PCCSOM 2026 Surgery 1: P.01.01 Skin and Subcutaneous Tissue (Part 1) PDF

PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) SURGERY LECTURE LAYERS OF THE SKIN LECTURER: Dr. Abraham Cinio DATE: August 6, 2024 TOPIC OUTLINE I...

PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) SURGERY LECTURE LAYERS OF THE SKIN LECTURER: Dr. Abraham Cinio DATE: August 6, 2024 TOPIC OUTLINE Introduction: Skin Anatomy and Histology of the Skin Skin Condition I. Epidermis INTRODUCTION: SKIN Outermost layer Complex organ encompasses the body’s surface and is Further divided into layers as a 30-day life cycle/turnover continuous with the mucous membranes. Accounting for from the innermost layer to the most superficial layer approximately 15% of total body weight, it is the largest An avascular layer and consists primarily of continually organ in the human body. regenerating keratinocytes Intact skin protects the body from external insults. Since the avascular layer all its nutrients come from the However, the skin is also the source of a myriad of dermis below through diffusion. pathologies that include inflammatory disorders, The tissue is stratified, forming four to five histologically mechanical and thermal injuries, infectious diseases, and distinct layers, depending on the location in the body benign and malignant tumors. - It is thinnest at the eyelids (75 to 150 μm) and thickest at the palms and soles (0.4 to 1.5 mm) ANATOMY AND HISTOLOGY OF THE SKIN Other cells found in this layer participate in cell immunity, skin pigmentation, and tactile sensation. Knowing the different layers of the epidermis can provide us with information on the management of certain pathologies arising from the skin including trauma. Layers of the epidermis that represent the different stages of the life cycle of a keratinocyte (from deep to superficial) are: 1. Stratum basale/Germinative Layer Composed of cuboidal to columnar epithelial cells Desmosomes bind keratinocytes together while hemidesmosomes connect it to other structures in the basement membrane This layer also lines the epidermal appendages that reside Figure 1. Schematic representation of the skin and its appendages. largely within the substance of the dermis and later serves Note that the root of the hair follicle may extend beneath the as a regenerative source of epithelium in the event of dermis into the subcutis. partial thickness wounds The skin is made up of tissues derived from both the For example in trauma, when you fall from a bike, or trip and get ectodermal and mesodermal germ cell layers. abrasions. We have classifications for the injuries occurred during It is a very versatile and highly adaptable organ with the process (superficial abrasions and thick abrasions) several characteristics affected by several factors like age, ethnicity, individual personal characteristics and others NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 1 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) Differences in skin pigmentation are based on the activity Superficial abrasion Thick (Full) abrasion of each individual melanocyte and not the number of management of for the melanocytes. abrasion will management, aside Tyrosinase is created and distributed into melanosomes – depend on until from cleaning the these are organelles that travel along the dendritic what layer of the wound, skin processes to eventually become phagocytized by epidermis is grafting is needed keratinocytes. It serves to protect the nuclear material of affected keratinocytes from damage by radiation. “In surgery, you don’t just cut and cut, we have to know Glutathione is a chemical commonly used in skin what we are cutting.” whitening which is commonly practiced in Asia Sometimes a simple lipoma can cause confusion or is Does the practice of skin whitening with glutathione increase the difficult to differentiate from other tumors arising from risk of the user to skin cancer? the skin and skin appendages. And of course, as mentioned, several diseases may arise from the skin. ★ With respect to cancer, glutathione metabolism is able to play Example: tumors arising from the nerves (neurons) but if both protective and pathogenic roles. It is crucial in the removal multiple, it is called neurofibromatosis and detoxification of carcinogens, and alterations in this pathway, 2. Stratum spinosum/Spiny Layer can have a profound effect on cell survival. This layer is from five to fifteen cells in thickness and is so named due to the spinous appearance of the intercellular Additional Notes: desmosomal attachments under the light microscopy Mechanism of Glutathione: Glutathione may affect skin The production of keratin in this cell layer is responsible pigmentation by inhibiting tyrosinase activity during for their eosinophilic appearance on hematoxylin and melanogenesis, either directly or indirectly. Direct eosin (H&E) staining. inactivation is done by binding to the active site of enzymes 3. Stratum granulosum containing copper ions, while indirect inactivation There are structures called lamellar granules within the eliminates free radicals and peroxides in antioxidative manners. During melanogenesis, glutathione converts cells that contain lipids and glycolipids that will ultimately eumelanin to pheomelanin and modulates depigmentation undergo exocytosis to produce the lipid layer around the of melano cytotoxic agents. cells It is in this layer that the keratinocytes manufacture many of the structures that will eventually serve to protect the 2. Langerhan Cells skin and underlying tissues from environmental insult 3-6% of the cells found in the epidermis At the superficial aspect of this layer, the keratinocytes These are monocyte-derived antigen presenting cells begin to undergo programmed cell death, losing all found usually on the stratum spinosum, and they cellular structures except for the keratin filaments and represent the adaptive immunity function of the skin their associated proteins They are impaired by ultraviolet B radiation and play a role 4. Stratum lucidum in the development of cutaneous malignancies Present in thick skin A differential diagnosis for rashes specially in children is Contain cells without cellular structures except for keratin the condition called “Langherans cell histiocytosis”, it is a filaments (translucent keratinocytes) rare disorder currently controversial with regards to the 5. Stratum corneum characterization of the cyst – whether it is a cancer or an Contains protein-rich keratinocytes surrounded by a lipid autoimmune disease and can be also seen on the lymph rich matrix nodes, lungs, liver CELLS OF THE EPIDERMIS: 1. Melanocytes Located in the stratum basale Responsible for the production of the pigment melanin It has a density of about 4 to 10 keratinocytes per melanocyte NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 2 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) Langerhans' cell and only few cases present with no apparent skin lesion. In histiocytosis the retroperitoneum there are only two cases reported in abnormal clonal the literature. proliferation of There are two possible explanations for what occurred in Langerhans' cells our patient. The most plausible theory is that the stimulus for retroperitoneal mass could be a massively enlarged lymph proliferation is node where precursor cells became neoplastic. This would unknown be consistent with a presumptive diagnosis of primary cutaneous nodal disease. Moreover, metastasis to the retroperitoneal involvement: 40% lymph nodes has been reported as relatively common blisters - reddish when compared to other sites such as liver, bone, brain bumps - rashes and skin. The less probable theory is the non-described “regression” phenomena of a cutaneous MCC, but we have 3. Merkel Cells not found a primary skin lesion. A.k.a. Merkel Ranvier Cells/Tactile Epithelial Cells fast-growing, painless nodule flesh-colored (shades of red, blue or purple o face, head or neck) areas not exposed to sunlight oval shaped mechanoreceptors light touch sensation Found usually in the digits, lips and bases of some hair follicles A very rare disorder associated with these cells is called “Merkel cell carcinoma” Merkel Cell Carcinoma/ Neuroendocrine Carcinoma/ Trabecular cancer 4. Lymphocytes It is the 2nd most common cause of skin cancer death. 65 years, prolonged sun exposure, Merkel cell polyomavirus, and immunosuppression Final Diagnosis: Skin lymphoma Diagnosis: do a biopsy in the particular region affected Remember: Different diseases of the skin can overlap. Be very cautious when treating. Make sure to check charts if patient’s condition is improving or not The origin of the cells of MCC arise from the amine 5. Toker Cells precursor uptake and decarboxylation cell system. Found in the nipple-areola complex Merkel cell carcinoma (MCC) is an aggressive cutaneous Sometimes associated with Paget's disease of the breast neuroendocrine carcinoma that affects elderly patients and Symptoms include appearance of erythema and scaly rash typically arises in sun-exposed skin. The disease is very rare on the skin of the nipple and areola NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 3 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) Further work up is indicated to rule out presence of c. Apoeccrine Glands invasive cancer Similar to an apocrine gland but opens directly to Complaints usually from nursing mothers the skin surface and does not present until puberty Paget's disease of the breast must be differentiated from Both types of glands are surrounded by a layer of atopic dermatitis, eczema, psoriasis, malignant melanoma, myoepithelial cells that can contract and assist in Bowen's disease, basal cell carcinoma, benign intraductal the excretion of glandular contents to the skin papilloma, nevoid hyperkeratosis of the nipple and areola surface (NHNA), squamous metaplasia of lactiferous ducts (SMOLD)/ Zuska's disease and pagetoid dyskeratosis. 2. Pilosebaceous Units Common Metastasis: Bone → The differential diagnosis of multicomponent unit made up of a hair follicle, Paget disease includes osteomalacia, which may be part of sebaceous gland, an erector pili muscle, and a the spectrum of osseous abnormalities accompanying sensory organ chronic renal insufficiency. Patients with mild osteomalacia these units are responsible for the production of may present with nonspecific bone pain and tenderness. hair and sebum They are lined by the germinal epithelium of the epidermis and thus serve as an important source of epidermal regeneration after partial- thickness Reading Assignments: injury or split-thickness skin graft Epidermal Appendages Derived from epithelial germ layer and lie These are specialized epithelial structures, obliquely in the dermis, with their deepest part connected to the surface epidermis but located reaching the hypodermis mainly within the dermis and hypodermis. 3. Nails Appendages serve functions that include They consist of three parts: (a) the root, covered lubrication, sensation, contractility, and heat loss. by the proximal nail fold, continuous with lateral Sources of new cells which can be used in re- nail folds; (b) the nail plate, comprised of hard epithelialization for SKIN GRAFTING keratin; and (c) the free edge, overlying the 1.Sweat Glands hyponychium a thickened epidermis. - Sweat glands are tubular exocrine glands, The nail lies on the nail bed, a richly vascular consisting of a secretory coil and an excretory connective tissue containing numerous duct. arteriovenous shunts. The proximal part of the nail bed is continuous Types: with the nail matrix, responsible for nail growth a. Eccrine Sweat Glands and adhesion. Main and most numerous sweat glands in humans These glands are the most effective means of temperature regulation in humans via evaporative heat loss BURN CLASSIFICATION Produce 10L per day of sweat in an adult Present almost everywhere on the skin (except A. Thermal mucous membranes), with a maximal density over 1. FLAME the palms, soles, axillae, and forehead Most common cause of hospital admission, Activated by the cholinergic system accompanied by inhalation injury and highest b. Apocrine Sweat Glands mortality Less abundant in humans 2. CONTACT Derived embryologically from the germ cells that 3. SCALD BURNS produce the pilosebaceous follicle and are, burns related to hot water therefore, structurally associated with it common in children; dangerous Found in the axillary, anogenital, and nipple regions, eyelids and external auditory canal B.CHEMICAL Consist of a secretory coil that is larger and more 3% of admitted burn Pt irregular in shape than that of eccrine glands Can potentially result in severe burns Activated by adrenergic system Acid: Coagulation necrosis (not all agents) & Secretion is initially odorless, but bacteria in the Eschar formation region may cause an odor to develop Alkali: Liquefactive necrosis & Deeper burns, will NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 4 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) make a hole-like burn Proper management of agents to prevent harmful 6 Degrees of Burn Depth (Pathological) reactions and systemic absorption Unique feature: After exposure Dupuytren (1832) Burn Wound Classification ★ need to immediately clean up or manage the chemicals a. First Degree – superficial that caused the burn to prevent further absorption and b. Second Degree - partial thickness reaction c. Third Degree - full thickness NOTE: It is best to dilute the agent than to neutralize it. d. Fourth Degree - involvement of underlying soft tissue Treatment for acidic or alkaline chemical burns are first and (muscle) foremost centered around dilution of the offending agent, e. Fifth Degree - burns go through muscle to bone typically using distilled water or saline for 30 minutes for f. Sixth Degree- charring bone acidic burns and 2 hours for alkaline injuries. Attempting To neutralize the offending agent is typically discouraged, as it Currently used classification does not offer an advantage over dilution and the neutralization reaction could be exothermic, increasing the amount of tissue damage. ELECTRICAL 3% of US hospital admissions Unique feature: has direct effects on the body such as the heart The heart is an electrical organ, it has the nerves and areas which offers the least resistance (blood vessels) SPECIAL CONCERNS 1. Cardiac arrhythmia: baseline ECG is recommended in ALL Pt. 2. Compartment syndrome with concurrent rhabdomyolysis: Common in high-voltage injuries; muscles are literally destroyed ➔ edema ➔ compartment syndrome Note: Vigilance for neurologic or vascular compromise, & fasciotomies should be done even in cases of moderate clinical suspicion 3. Long-term neurologic symptoms and cataract development: A. First Degree (Superficial Burn) neuro and ophtha consultations to define baseline only the epidermis is involved with noted: functions - Local pain Superficially there is just pinpoint burns; but we - Erythema need to know what’s going on inside the body - NO blister formation What’s happening inside the body is more - Systemic response is absent or mild important and extensive. Require no treatment (except for large burns of infants or the elderly) - Because of the presence of stratum germinativum, there Burn Assessment could be a source of reepithelization. B. Second Degree (Partial Thickness) I. Superficial Partial Thickness Epidermis and dermis Appear red, moist Blister formation Tactile and pain sensors are intact Heal in 14 to 21 days with minimal scarring NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 5 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) II. Dermis A mesoderm-derived tissue It consists primarily of three unique components: - A fibrous structure - Ground substance that surrounds the fibers - The cell population that is supported by the dermis The dermis houses the neurovasculature that supports the epidermis and facilitates interaction with the outward environment It is thinnest in the eyelids and thickest at the back 98% of its dry weight is composed of collagen II. Deep Partial Thickness Entire epidermis and most of dermis, leaving only the skin LAYERS OF THE DERMIS appendages intact. Because of the presence of appendages, it therefore 1. Papillary Layer (Superficial) – 20% provides the epithelial cells for resurfacing (takes time) Composed of areolar loose connective tissue Mottled appearance with areas of waxy- white injury Highly vascularized Surface is dry and anesthetic Dermal ridges (contribute to fingerprints) Heals spontaneously in 4-6 weeks Nerve endings and touch receptors (Meissner’s corpuscle) With unstable epithelium, may result in late hypertrophic are also shown in the dermis scarring and marked contracture formation 2. Reticular Layer/Deep – 80% Some can heal on its self (with the help of topical Dense irregular connective tissue treatment) and healing takes time as well - Collagen fibers: contributes to the strength of the skin - Elastic fibers: for stretch/recoil - Both types of fibers decrease in number as we age Less vascular (not literally lower in number but smaller compared to papillary layer) stretch marks: tears in dermis Additional information: 1. Langer Lines Langer’s lines are lines of tension or cleavage within the skin that are characteristic for each part III. Third Degree (Full Thickness) of the body Destruction of epidermis, dermis, and underlying In microscopic sections cut parallel with these subcutaneous tissue lines, most of the collagenous bundles of the Appear white, cherry red, black reticular layer are cut longitudinally, while in Thrombosed blood vessels may be visible sections cut across the lines, the bundles are in cross section Elasticity of burned dermis is destroyed The cleavage lines correspond closely with the Dry, leathery texture crease lines on the surface of the skin in most parts of the body These cleavage lines are of particular interest to the surgeon because an incision made parallel to the lines heals with a fine linear scar, while an incision across the lines may set up irregular tensions that result in an unsightly scar In other areas of the body, Langer’s lines are visible or can easily be seen by compressing the skin On the scalp, Langer’s lines are not obvious due to the presence of hair and thickness of the skin NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 6 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) These tumors arise primarily from melanocytes at the epidermal-dermal junction but may also originate from 2. Kraissl’s Lines Kraissl's lines are a set of anatomical skin lines mucosal surfaces differ from Langer's lines in that unlike Langer's Do a complete PE, especially rectal examination, in cases lines, which are defined in term of collagen of inguinal lymphadenopathy. One of the drainage system orientation, Kraissl's lines are are oriented of the perianal region is the inguinal region. It can perpendicular to the action of the underlying metastasize and become anal cancer muscles Kraissl's lines coincides with wrinkle lines, Case 3: A young taekwondo patient sought consult at the ER although not always, and tend to be perpendicular complaining of back pain after a tournament. Patient was to the muscle action evaluated, X-ray was done at the back, ultrasound was also done to Kraissl's lines are found by studying the direction rule out blunt trauma to the abdomen, kidneys, etc. Patient was of underlying muscle fiber prescribed a pain reliever ruled in as a case of soft tissue contusion Kraissl transposed wrinkle lines over diagrams of secondary to trauma. Patient was sent home. After a few hours, the underlying musculature and showed that patient returned due to severe back pain and was eventually these lines are mostly perpendicular to the admitted. Pertinent physical finding: positive costovertebral angle muscles tenderness on both sides. 10/10 pain scale. No history of He noted that the orientation of attachments hematuria and fever. Initial CBC and urinalysis were unremarkable. between the skin and muscle was largely CT scan was done and a lesion at the retroperitoneal area was perpendicular to the underlying muscle found which may indicate a possibility of bleeding. But upon Collagen runs generally parallel to wrinkle lines and is laid down parallel to scars assessment, draining was not needed and the patient was placed Therefore, in a scar placed perpendicular to the under observation. Patient’s vital signs were normal. Repeat CT underlying muscle, collagen will be laid down in scan was done after 5 days for assessment due to persistent, the same direction as is usual in the wrinkle lines intermittent pain (not lower than 5) but the same result was and the septa between skin and muscle obtained. The doctor decided to do a CT-guided aspiration of the presumed bleeding. The specimen was brought to the histopath. 3. Stretch marks (Striae) are a result of damage to the dermis FINAL Diagnosis: Melanoma in the retroperitoneal area Striae gravidarum – atrophic linear scars that Remember: Any trauma can manifest any symptom for the represent one of the most common connective tissue changes during pregnancy first 3 days – critical period of observation. Red stretch marks – striae rubrae For the taekwondo case: Advise the patient that the pain White stretch marks – striae alba reliever is a temporary medication Depending on the physical examination, always tell the Cells of the Dermis trauma patient that the first 3 days are critical. Observe 1. Fibroblast any hematuria, or changes in bowel habits. Fundamental cells of the dermis Responsible for producing all the dermal fibers and 2. Dermal Dendrocytes the ground substance within which the fibers reside Comprised of a variety of mesenchymal dendritic cells Workhorses of wound healing and provide the recognizable mainly by immunohistochemistry normal mechanical resistance of the skin Responsible for antigen uptake and processing for They are typically spindle- or stellate- shaped and presentation to the immune system, as well as the have a well-developed rough endoplasmic reticulum, orchestration of processes involved in wound healing and typical of cells engaging in active protein production tissue remodeling Typically found in the papillary dermis around vascular Case 2: An elderly male patient who complains of an enlarged structures as well as sweat glands and pilosebaceous units lymph node on his right inguinal area. There was no history of 3. Mast cells trauma and no manifestations associated with urinary tract Effector secretory cells of the immune system that are infection. responsible for immediate type I hypersensitivity reactions Pertinent PE: Pigmented lesion on the sole of the right foot. Apparently, the patient did not know any mole/nevus on the sole of his right foot. Full thickness biopsy of the lesion revealed melanoma. NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 7 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) Which collagen type predominates during wound healing? *Most of the time, ask the patient if there had been a mole in the affected area, and they usually say there was none Type I collagen is the major component of the Examine the extremities (such as the case about inguinal extracellular matrix in skin. Type III, becomes more lymphadenopathy), perform rectal exam prominent and important during repair process Do not forget to inspect and palpate Sometimes there will be no tumors; remember that melanoma will present with several features Question: Increased nevus production/appearance - Normally, nevus will increase in number as a person age - What is important is that a doctor must take note of how the observation of lesions is done - Ex. ABCDE mnemonic - Observe the criteria listed in the ABCDE; if present, the patient, ordoctor may opt for biopsy Skin lesions including nevi warrant close monitoring Assessment is via ABCDE and is simple A Asymmetry -Take note of the previous appearance -Pictures may help to compare B Border III. Hypodermis -Irregular or well-defined Fatty layer below the dermis C Color Functions in body processes of thermoregulation and -Changes from previous nevi energy storage -Is it lighter or has it become a different shade SKIN CONDITIONS D Diameter -Has it increased in diameter -Some books say that lesions larger than 6mm may have a. higher chance of developing skin cancer MELANOMA E Evolution Individuals with a dysplastic nevus have a 6-10% overall -Changes noted from when the lesion was initially noted lifetime risk of melanoma with tumors arising from pre- existing nevi Congenital nevi increase the risk of melanoma in proportion to its size The American cancer society: - 6th most common cancer in males, - 7th most common cancer in females The most common sites of metastasis of melanoma are the lung and liver. These are followed by the brain, gastrointestinal tract, distant skin, and subcutaneous tissue. Incidence: - Men are more commonly affected than females Management of melanoma (and other skin malignancies): - In females: lower extremities Tissue diagnosis - In males: head and trunk - Confirms type of lesion or cancer through full-thickness *In practice, doctor is yet to encounter a patient with a biopsy of the skin melanoma from a dysplastic nevus - Ex. Punch, excision, or incision biopsies NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 8 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) skin that is removed) or rotation flaps of skin from other sites may be used to cover the wound resulting from the wide local excision, but most cutaneous melanoma excisions can be closed without placement of a skin graft. Sentinel Lymph Node Biopsy: The removal of the sentinel lymph node (the first lymph node to which the cancer is likely to spread). A radioactive tracer and/or blue dye is injected near the tumor before surgery in a process called lymphatic mapping (or lymphoscintigraphy). The radioactive tracer or dye flows through the lymph channels in the skin to first draining lymph nodes in the region(s) around the melanoma. The injection of the radioactive tracer is performed in the Nuclear Medicine Department either the evening before surgery or several hours before surgery. A body scan is then performed to help the surgeon localize the sentinel lymph node before beginning the operation. This first lymph node(s) to receive the tracer is removed for biopsy. A pathologist then views the tissue under a microscope to look for cancer cells and often uses additional tissue stains (immunostains) to determine whether microscopic evidence of melanoma is evident in the regional lymph nodes. If cancer cells are not found, no further surgery is necessary. When the type of skin cancer is identified, the appropriate management is next including staging of the disease Local, internal and distal spread is evaluated and risk factors are explained to the patient to let them know the plan for their case For every lesion where malignancy is entertained, do a biopsy/’taking a part” - Patients may be hesitant at agreeing to undergo biopsy - Explain to the patient that it is not a very complicated procedure For smaller lesions: Punch Biopsy: Punch biopsies involve taking a deeper - Excisional biopsy is done/total removal sample of skin with a biopsy instrument that removes a - Incision means taking a small part short cylinder, or "apple core," of tissue. After a local - Punch, core biopsies still take a part but uses an anesthetic is administered, the instrument is rotated on instrument the surface of the skin until it cuts through all the layers, For skin lesions more than 6mm, sometimes when it including the dermis, epidermis, and the most superficial grows too quickly, it is considered as Evolution, and parts of the subcutis (fat). surgical excision is done Excisional and Incisional biopsy: When the entire tumor is For increasing number of nevi, it is genetic removed, the procedure is called an excisional biopsy. If - Not all cases of increasing numbers of nevi are normal only a portion of the tumor is removed, the procedure is - Ex. If nevi have been found to be numerous since birth and referred to as an incisional biopsy. When possible, has been on a steady rise as the person ages, it may be excisional biopsy is the preferred method when melanoma is suspected. An excisional biopsy, also called a wide local questionable and is subject to evaluation incision, involves surgical removal of a tumor and some For large lesions: normal tissue around it. The amount of normal tissue taken - Excise a part of the lesion (also called the clinical margin) depends on the thickness of - Look for a suitable edge/border the tumor. In the case of possible melanoma, skin grafting - The border of the lesion will include normal tissue (taking skin from another part of the body to replace the - Full thickness must be removed as much as possible NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 9 | 14  PCC SOM 2026 SURGERY 1 - P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) The subcutaneous may be excised - Ex. An incisional biopsy that is positive for melanoma will require staging as soon as possible CANCER STAGING & DIAGNOSIS Melanoma is staged according to depth and size For any cancer, staging is for prognostication and risk stratification For elderly patients: These patients may have comorbidities like heart failure. Will the management be aggressive? Consider risk stratification Clinical Staging Melanoma in the foot with inguinal lymphadenopathy and has subsequent lung metastasis. How will we approach this? Stage I and II: no evidence of metastases (localized disease) These are the two most common references used for Stage III: clinical or radiographic evidence cancer staging: Stage IV: distant metastases 1. American Joint Committee of Cancer (AJCC): Tumor, Node, Metastases(TNM) Pathologic Staging Most cancers are staged according to this committee Stage I and II: no evidence of metastases No longer considers the Clark Level which is the staging - Cutaneous lymphoscintigraphy system that describes the depth of melanoma as it grows - Lymphatic mapping in the skin - Sentinel lymph node biopsy Full thickness biopsy is done to check the depth of Stage III: Regional lymph node and intralymphatic sites invasion of melanoma stage IV: Distant metastases -histologic documentation - The deeper the melanoma has invaded, the higher the chance of metastases Lymphoscintigraphy is a special type of nuclear medicine imaging that provides special pictures of the lymphatic system, which 2. NCCN (National Comprehensive Cancer Network) transports fluid throughout your immune system. is also a cancer staging instrument Lymphoscintigraphy is often used to identify the sentinel lymph node, or the first node to receive the lymph drainage from a tumor. Management is a multi-disciplinary approach May include different departments like oncology and surgery In radiology, different diagnostics and imaging modalities are included to assess the lesion depending on the pre- operative assessment NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 10 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) SENTINEL LYMPH NODE BIOPSY (SLNB) (FNA) biopsy is the removal of tissue, fluid, or very small pieces from a tumor using a thin needle. Local anesthetic is A technique which identifies the first draining sometimes used to numb the area, but the test rarely lymph node from the primary lesion which is causes much discomfort and leaves no scar. A small needle called the sentinel lymph node is inserted into the abnormal area in almost any part of the A standard staging procedure to evaluate body, guided by imaging techniques, to obtain a tissue regional nodes for patients with clinically known biopsy. This type of biopsy can provide a diagnosis without negative malignant melanoma surgical intervention. FNA is not used for diagnosis of a SLN is common in breast cancer suspicious mole, but may be used to biopsy large lymph nodes near a melanoma to see if the melanoma has metastasized (spread). A computed tomography scan (CT or CAT scan)—an X-ray procedure that produces cross- sectional images of the body—may be used to guide a needle into a tumor in an internal organ such as the lung or liver. Diagnostics: Ultrasound: - Evaluates lesions and differentiates them whether cystic or solid, or a combination Diagnostics: X-ray/Mammogram - Gives other information regarding the breast lesion - If the breast is mixed cystic and solid, perform FNAB and send fluid to the laboratory - Cystic lesions: If the fluid is clear, the doctor may or may not send it to the lab, but this depends Back to the example: core needle biopsy turned out malignant Perform a sentinel lymph node evaluation - Assess the breast and inject a certain dye and a radioactive substance to the lesion - The first lymph node (affected lymph node) that the dye attaches to is considered the sentinel LN The radiation produced by the dye and the radioactive substance will be detected by a radioactive detector High level of radiation produced means positive, excise the lesion and the SLN E.g. Patient came in seeking consult due to breast mass. On a Clinically, for sentinel node, no lymph node can be palpated physical exam, the mass is most likely malignant. Indication for SLNB: no lymph node is palpated during PE The first thing to do to evaluate breast tumors: ultrasound but positive biopsy and then do a biopsy If the LN is palpable, this could already be positive for The most common is core needle biopsy for solid tumors cancer and does not need to go through a SLN evaluation If the ultrasound shows cystic lesions, do a fine needle - Take a sample instead aspiration biopsy (FNAB) - Do a core biopsy (large lymph node) or cautery Puncture and remove the cyst (tumor that is fluid-filled) Clinically, if the cancer is metastatic, there is also no need for a SLN Core Biopsy: A core biopsy is the removal of tissue using a evaluation, as this evaluation is for very early cancers wider hollow needle. Most are performed with local SLNB includes pre-operative lymphoscintigraphy with anesthetic and sedation only without the need for general intradermal injections of: anesthesia. Patients go home with nothing more than a band-aid. - Technetium 99-labeled sulfur colloid to delineate Fine needle aspiration Biopsy: A fine-needle aspiration lymphatic drainage; and NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 11 | 14  PCC SOM 2026 SURGERY 1 - P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) Intraoperative intradermal injection of isosulfan or Measures the depth of penetration of the lesions from the methylene blue dye near the tumor/site top of the granular layer of the epidermis into the dermal - If the lesion is small and the surgeon removed it, the dye layer maybe directly injected on the site of the excised lesion Directly related to the risk of disease progression The radioactive tracer-dye combination allows the SLN to be identified in 98% of cases An incision over the lymph node basin of interest allows nodes to be excised and studied with H&E and IHC Before it spreads to the LN: 99% survival rate Survival rate decreases to 15% for patients with advanced disease Presence of tumor ulceration, histopathologic finding of mitotic rate of > 1 per mm2,and metastasis are all associated with worse prognosis In the presence of regional node metastasis, the number of nodes affected is the most important prognostic indicator For stage IV disease, the site of metastasis is strongly associated with prognosis, and elevated lactate Image shows injection of radioactive technetium-99-labeled sulfur dehydrogenase (LDH) is associated with a worse prognosis colloid tracer at the primary cutaneous melanoma site. A: Lymphoscintigraphy of a malignant melanoma of the right heel; GROWTH PHASES SNL in both right popliteal fossa and inguinal region. B: Lymphoscintigraphy of a malignant melanoma of posterior upper Some types of melanomas are aggressive; while some arm ; SNL in the right axillary region. C: Lymphoscintigraphy of a types take years to develop metastasis facial melanoma; SNL in the submandibular region. INTRALYMPHATIC LOCAL & REGIONAL METASTASES A. Satellite Metastases Grossly visible cutaneous and/or subcutaneous metastases occurring within 2cm of the primary melanoma B. Microsatellites Microscopic and discontinuous cutaneous and/or subcutaneous metastases found on pathologic 1. Radial Growth Phase examination adjacent to a primary melanoma Melanoma appears as an irregular plaque C. In Transit Metastases Cells may invade the dermis but do not form a nodule Clinically evident cutaneous and/or subcutaneous 2. Vertical Growth Phase metastases identifies at a distance greater than 2cm from When there is vertical growth phase, the risk of chances of the primary melanoma metastatic spread is higher because lymphatics and vascular structures are located in the reticular Breslow Tumor Thickness subcutaneous tissue. Replaced the Clark's level as the most important prognostic indicator for melanoma staging NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 12 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) 3. Lentigo Maligna Melanoma (10%) TYPES OF MELANOMA Least aggressive type Sun-exposed areas of the skin Men < Women >3cm, areas of regression Precursor lesion: lentigo maligna or Hutchinson freckle - radial growth phase only 4. Acral Lentiginous Melanoma 2-8% Whites 35-60% Blacks, Hispanics, Asians Palms, soles, subungual Some types of melanomas are aggressive, while some types take Irregular pigmentation years to develop metastasis >3cm Long radial growth phase 1. Superficial Spreading Melanoma Most common; 70% of cases Arise in a pre-existing nevus Early radial growth phase Management of Melanoma 2. Nodular Melanoma (15%-30%) Most aggressive type Typically does not arise from a pre-existing nevi Vertical growth phase is a hallmark feature Men 2x > Women 5% of the lesions are amelanotic (no pigment) which may lead to a delay in the diagnosis Wide excision recommended margin: 0.5 - 1 cm If melanoma is at least 4mm, then at least 2 cm margin from the edges of the melanoma should be excised NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 13 | 14  PCC SOM 2026 SURGERY 1 P.01.01 SKIN AND SUBCUTANEOUS TISSUE (Part 1) This becomes a problem when the melanoma is located in CHECKPOINT the face or nose. Some form of reconstruction is needed if a curative intent of melanoma is planned 1. It is the 2nd most common cause of skin cancer death. Staging is needed A. Merkel cell carcinoma Included in the management, especially in melanomas B. Cutaneous lymphoma found in the extremities are isolated limb perfusion and C. Basal cell carcinoma infusion 2. The production of keratin in this layer of epidermis is The purpose is to administer high doses of chemotherapy responsible for their eosinophilic appearance on hematoxylin and eosin (H&E) staining. usually/commonly melphalan to an affected limb while A. Stratum Basale avoiding systemic drug toxicity B. Stratum spinosum The most common non-cutaneous site of metastasis of is C. Stratum granulosum ocular melanoma 3. Which layer of the epidermis contains protein-rich Melanoma of the mucous membranes most commonly keratinocytes surrounded by a lipid rich matrix presents in the oral cavity, oropharynx, nasopharynx, A. Stratum basale paranasal sinus, anus, rectum, and female genitalia. B. Stratum spinosum Patients with this presentation have a worse prognosis C. Stratum corneum (10% 5-year survival) than patients with cutaneous 4. Layer of dermis which composed of areolar loose connective melanomas tissue, and it is highly vascularized A. Papillary Layer In patients with stage Ill or greater disease, there is a high B. Reticular Layer risk for distant metastasis, and imaging is recommended 5. These are monocyte-derived antigen presenting cells found for baseline staging. These patients should receive usually on the stratum spinosum, and they represent the additional imaging that includes CT (with IV contrast) of adaptive immunity function of the skin the chest, abdomen, and pelvis; whole-body position A. Markel cells emission tomography (PET)-CT; or brain magnetic B. Langerhan cells resonance imaging (MRI). C. Melanocytes 6. Effector secretory cells of the immune system that are responsible for immediate type I hypersensitivity reactions READING ASSIGNMENT A. Dermal dendrocytes 1. Isolated Limb Perfusion B. Mast cells A surgical treatment for in-transit metastases C. Markel cells It involves cannulation of the main artery and the 7. Multicomponent unit made up of a hair follicle, sebaceous vein of the affected limb, connecting these gland, an erector pili muscle, and a sensory organ cannulas to a cardiopulmonary bypass machine, A. Pilosebaceous Units and applying a tourniquet to that extremity. B. Apocrine sweat Glands 2. Isolated Limb Infusion C. Eccrine Sweat Glands A regional technique used to treat advanced 8. A technique which identifies the first draining lymph node from melanoma or sarcoma confined to an arm or leg the primary lesion Chemotherapy medications are injected into an A. Sentinel Lymph Node Biopsy artery of the affected arm or leg while the limb’s B. Core Biopsy blood supply is temporarily cut off with a C. Fine Needle aspiration Biopsy tourniquet. 9. Most aggressive type of Melanoma A. Superficial Spreading Melanoma B. Nodular Melanoma C. Lentigo Maligna Melanoma 10. Least aggressive type of Melanoma A. Superficial Spreading Melanoma B. Nodular Melanoma C. Lentigo Maligna Melanoma NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 14 | 14