Major Salivary Glands Lecture PDF

MAJOR SALIVARY GLANDS Anatomical Techniques I Meghan Dorrell, MHS, PA(ASCP)  Robbins Chapter 16; pg. 747-752 Netter plates: 18, 70, 71 READINGS: Lester pg. 448 – 451 Hruban Chapter 7 (pg 43) ...

MAJOR SALIVARY GLANDS Anatomical Techniques I Meghan Dorrell, MHS, PA(ASCP)  Robbins Chapter 16; pg. 747-752 Netter plates: 18, 70, 71 READINGS: Lester pg. 448 – 451 Hruban Chapter 7 (pg 43)  Identify the major salivary glands and their ducts anatomically Differentiate between the type of salivary gland cells to include their secretions and functions Recognize the histological differences between the major salivary glands Compare and contrast common pathologies identified in the major salivary glands OBJECTIVES: Formulate a differential diagnosis based on gross photos of pathology in the salivary glands Summarize the clinical features of common salivary disorders Formulate a gross plan for dissecting a salivary gland resection Create a gross description for a salivary gland resection  Anatomy Histology Common Pathology OUTLINE: How to gross CAP considerations IOC considerations  How many major salivary glands SALIVARY GLANDS are there? Can you name them? Function: produce and secrete saliva Digestive and protective function Saliva solute components (0.5%): Ions Immunoglobulin A: decrease bacterial infrections Lysozyme: antibacterial enzyme Mucin Lingual Lipase: from minor salivary glands Salivary amalyse: enzyme breaks down carbohydrates DUCTS: Parotid gland: Stensen’s duct Submandibular gland: Wharton’s duct Sublingual gland: Bartholin’s duct  PA ROT I D G L A N D Weight: 15 – 30 grams Located anterior and inferior to ear; between skin and masseter muscle Stensen’s duct- empty into oral cavity opposite the second maxillary molar Intraparenhymal lymph nodes present Produces only serous secretions, only serous acini PA ROT I D G L A N D - FAC I A L N E R V E Facial nerve controls facial movement and expression Function can be lost/altered secondary to parotid pathology Divides the parotid gland into superficial and deep lobe SUBMANDIBULAR GLAND Weight 7 – 15 g Located inferior to the body of the mandible Wharton’s ducts empty into the floor of mouth on both sides of the lingual frenulum - Sublingual caruncle Produces serous and mucous (serous predominates) Received as part of Level 1B neck dissections SUBLINGUAL GLAND Weight: 2- 4 g Located inferior to the tongue and deep to the oral cavity mucosa Mixed mucinous and serous (predominately mucinous) Bartholin’s ducts empty into the floor of mouth lateral to the sublingual caruncle - Sublingual fold SALIVARY GLANDS: EMBRYOLOGY/AGING Salivary glands are of ectodermal origin Arise from solid epithelial buds of oral mucosa Aging: Generally, connective tissue diminishes with aging/maturation Myoepithelial cell function decreases → less secretion of saliva → dry mouth (xerostomia) → halitosis (bad breath) Function of acinar cells decreases → altered protein content and less saliva production  Anatomy Histology Common Pathology OUTLINE: How to gross CAP considerations IOC considerations  SALIVARY GLANDS:HISTOLOGY Function unit: terminal branched tubulo-acinar structure of serous or mucous cells Serous demilunes: semilunar serous cap on a mucous cell Acinar component can produce serous, mucinous or mixed secretions Myoepithelial cells: surround acini, mediate contractions/secretions Serous acini: Secrete proteins in isotonic Mucinous acini: watery fluid (serous fluid) Produces acid and neutral Pyramidal shaped cells: contain sialomucins PAS+ intracytoplasmic secretory Basally located, granules condensed nucleus Produces zymogen enzyme  SALIVARY GLANDS:HISTOLOGY Ducts - Intercalated ducts: lined by secretory cells cuboidal secretory cells - Striated ducts: ions are resorbed and secreted to produce hypotonic saliva  SALIVARY GLANDS: HISTOLOGY Minor Salivary Glands: found in lips, ginigva, floor of mouth (FOM), cheek, hard/soft palate, tongue, tonsils, oropharynx Von Ebner glands of the tongue: Serous acini only Base/lateral border of tongue and palate: Predominantly mucinous acini Lip, cheek, apex of tongue: Mixed serous and mucinous LEARNING CHECK: 1. Describe the location of the parotid gland? 2. What is the duct’s name for the submandibular gland? 3. Compare the histologic features of the parotid gland and the sublingual gland? 4. Define a serous demilune 5. What is the relationship of the facial nerve to the parotid gland 6. Which major salivary gland will you receive with a Level IB neck dissection?  Anatomy Histology Common Pathology OUTLINE: How to gross CAP considerations IOC considerations  Xerostomia Sialolithiasis COMMON PAT H O LO GY: Sialadenitis MAJOR SALIVARY Pleomorphic adenoma GLANDS Warthin tumor Mucoepidermoid Carcinoma XEROSTOMIA Dry mouth due to a decrease in saliva production Associated with: - Sjogren Syndrome (autoimmune disorder) - Radiation therapy of head and neck cancers - Side effect of prescription medication Presents as: - Dry mucosa and/or atrophy of tongue Complications include: - Increase dental caries - Candidiasis (fungal infection with candida) - Dysphagia (difficulty swallowing) - Dyspnea (difficulty breathing/shortness of breath) SIALOLITHIASIS (STONES) Stones related to obstruction of orifice by impacted food or local edema after injury Can lead to bacterial infections (MC Staph aureus) Leads to dilated ducts Clinical manifestation: Pain and swelling of gland Morphological: necrosis and edema of salivary gland can be present Can lead to chronic inflammation -> Sialadenitis (next slide) S I A L A D E N I T I S - I N F L A M M AT I O N Causes: trauma, viral, bacterial, autoimmune (Sjogren syndrome) MC viral cause is mumps Prevalent form is mucocele (CPT 88304) - Fluctuant swelling of lower lip with blue hue - Due to blockage/rupture of minor salivary gland duct - MC inflammatory salivary gland lesion SALIVARY GLAND NEOPLASMS 65 – 85% arise in the parotid gland; 10% submandibular Malignant potential is inversely proportional to gland size - Majority of sublingual tumors and 50% of minor salivary gland tumors are malignant - Majority of parotid tumors are benign - 40% of submandibular tumors are malignant MC neoplasm: Pleomorphic adenoma PLEOMORPHIC ADENOMA MC salivary gland neoplasm Benign; mixture of ductal, myoepithelial and mesenchymal cells Can arise from radiation exposure Make up 60% of parotid tumors Risk of malignant transformation increases with time Recurrence possible if unencapsulated Morphology: - round, well demarcated - Rarely excessed 6 cm - Cut surface: gray-white with myxoid and blue translucent areas of chondroid stroma PLEOMORPHIC ADENOMA: GROSS DIFFERENTIAL White, rubbery to firm, translucent or cartilaginous Diffuse infiltration/cystic degeneration = acinic cell or mucoepidermoid carcinoma Hemorrhage, necrosis, or frank invasion = carcinomas WARTHIN TUMOR Papillary Cystadenoma Lymphomatosum 2nd most common salivary gland tumor Mostly arises in parotid gland, inferior pole Benign, occur more frequently in men 8x increased risk in smokers WARTHIN TUMOR: GROSS DIFFERENTIAL Circumscribed, orange/tan, often cystic Thick brown/black fluid within cyst Cyst lined with papillary nodules Can be multifocal and 10% can be bilateral  Gross differential: MUCOEPIDERMOID CARCINOMA Low grade/intermediate grade: well The most common primary malignant salivary gland neoplasm circumscribed and cystic (cyst 60 – 70% occur in the parotid gland contain mucin) Account for large fraction of minor salivary gland tumors High grade: infiltrative and solid Pale gray-white  Anatomy Histology Common Pathology OUTLINE: How to gross CAP considerations IOC considerations  CPT: 88305 MINOR SALIVARY GLAND BIOPSY OF THE LIP Patients with Sjogren syndrome have labial biopsy of normal appearing mucosa for diagnosis Number of biopsies recommended: - > 0.2 cm: at least four - < 0.2 cm: minimum of size 3 levels are recommended What steps would you take to Let’s gross it! gross these mucosal biopsies?  Why would we receive a salivary SALIVARY GLAND RESECTION: gland resection in the gross CPT: 88307 room? Let’s gross it! Recommended sampling: - Tumor to soft tissue margins 1. Orientation (if present) - Tumor to uninvolved gland 2. _________ - Tumor to any grossly identified ducts/nerves 3. 3D measurement - RS of uninvolved gland 4. Describe outer surface: look for large nerves - Parotid: 5. Ink the outer surface What is the rule of thumb of how many sections of tumor to 6. Serially section perpendicular to long axis (2-3 submit? mm) 7. Describe lesion: 8. Describe remaining uninvolved cut surface 9. Take sections  E X A M P L E D I CTAT I O N : Received fresh labeled “patient’s name” and “parotid” is a 10 g, 6 x 5 x 3 cm unoriented parotid gland surrounded by adipose tissue that is 0.1 to 0.5 cm in thickness. The outer surface is roughed with a 0.5 cm in length and 0.2 cm in diameter nerve identified. The outer surface is inked black. Serially sectioning reveals a 4 x 3 x 3 cm firm tan white homogenous well circumscribed lesion within the gland that is 0.5 cm from the closest soft tissue resection margin. The lesion does not grossly involved the large nerve. The remaining parenchyma is tan yellow lobulated glandular tissue. No lymph nodes are grossly identified. Representative sections are submitted as follows: A1-2: Full face of lesion, bisected A3: lesion to closest soft tissue resection margin A4: lesion to large nerve A5: uninvolved gland  Anatomy Histology Common Pathology OUTLINE: How to gross CAP considerations IOC considerations CAP PROTOCOL: MAJOR SALIVARY GLANDS Per the synoptic report, what do you need to state in your gross dictation: Procedure: parotidectomy? Submandibular? Sublingual resection? Tumor: - Focality - Site - Laterality - Size (3D) Macroscopic tumor extent - pT3: Extraglandular soft tissue? - pT4a: Facial nerve? Skin? Ear Canal? Mandible - Pt4b: skull bases? Pterygoid plates? Carotid artery encasement? Margin status Lymph nodes - If positive: size of nodal metastatic deposit, ENE? What would be the rule for major salivary gland tumors? An easy way to remember it?  KEY POINTS TO REMEMBER FROM THE CAP PROTOCOL: Adenoid cystic carcinoma should NEVER be assigned low grade/biologic potential category (p15) Presence of perineural invasion (neurotropism) IMPT predictor of poor prognosis in H&N cancer. (p17) Facial nerve dysfunction and perineural involvement indicate a neck dissection, postoperative radiation therapy and affects survival rate (p17) Primary salivary gland carcinoma involving facial nerve associated with recurrent tumor and decreased survival (p18) Complete surgical excision with free surgical margin is primary mode of therapy for salivary gland cancers (p18) Cross section diameter of largest lymph node metastasis measured AT TIME OF GROSS is impt (p19) Selective neck dissection is 10 or more LN; radical/modified neck dissection is 15 or more LN (p19) Status of cervical lymph node is the single most important prognostic factor in aerodigestive cancer (p21) Extraparenchymal extension equals clinical or macroscopic evidence of invasion of soft tissue or nerve. Microscopic evidence alone does not count (p24) ***  Anatomy Histology Common Pathology OUTLINE: How to gross CAP considerations IOC considerations I O C C O N S I D E R AT I O N S : Why do you think we would receive a salivary gland tumor for IOC? ANY QUESTIONS?