Benign Tumours (2) PDF

BENIGN TUMOUR S I. Epithelial Tumours 1. Papilloma Definition: benign epithelial tumour of surface epithelium. Grossly: non-capsulated papillary growth, rarely sessile but more commonly pedunculated. Mi...

BENIGN TUMOUR S I. Epithelial Tumours 1. Papilloma Definition: benign epithelial tumour of surface epithelium. Grossly: non-capsulated papillary growth, rarely sessile but more commonly pedunculated. Microscopically: branched core of vascular connective tissue covered by hyperplastic [………] epithelium. basement membrane is intact. Types: according to covering epithelium, it is divided into: Squamous cell papilloma: Transitional cell papilloma: Columnar cell papilloma:  2. Adenoma Definition: benign epithelial tumour of glandular epithelium. Sites: all endocrine and exocrine glands + GIT. Grossly: well defined, round or ovoid, capsulated mass. Cut section may be solid, cystic or cystic with papillae. Microscopically: several types are known: Simple adenoma: epithelial cells arranged in solid masses or acini separated by delicate connective tissue stroma. Fibroadenoma: epithelial cells arranged in acini separated by thick connective tissue stroma. It is a mixed adenoma showing proliferation of fibrous tissue between epithelial cells. Best example is fibroadenoma of the breast. Cystadenoma: secretions formed inside acini are retained forming cystic spaces. Best example is cystadenoma of the ovary. Papillary cystadenoma: the epithelium lining cysts continues to proliferate to form papillae. Best example is papillary cystadenoma of the ovary. Effects: may function [endocrine glands] or change into adenocarcinoma.  II. Benign Tumours of Mesenchymal Origin A. Connective Tissue Tumours 1. Fibroma Definition: benign mesenchymal tumour of fibrous tissue. Sites: Subcutaneous and submucous tissues. Intermuscular septa, fascia, ligaments. Fibrous stroma of any tissue as ovary, breast, etc.. Grossly: well defined, round or ovoid, capsulated mass. Cut section is whorly & may be soft & pink [soft fibroma] or hard & gray [hard fibroma]. Microscopically: tumour is made up of fibroblasts [spindle-shaped cells with spindle-shaped nuclei] separated by collagen bundles. In soft fibroma, cells > collagen. In hard fibroma, collagen > cells. Secondary changes: hyaline and myxoid degeneration, calcification, ossification and malignant change into fibrosarcoma. Desmoid Tumour: recurring fibroma of the muscular aponeurosis of the anterior abdominal wall. Commonly seen in females with repeated delivaries. The tumour is noncapsulated, infiltrates the surroundings, recurs after removal, does not show cellular features of malignancy and does not give metastatsis.  2. Lipoma Definition: benign mesenchymal tumour of fatty tissue. Sites: Subcutaneous and submucous tissues. Intermuscular septa, fascia, ligaments. Fatty stroma of any tissue as ovary, breast, etc.. Grossly: well defined, round or ovoid, capsulated mass. Cut section is yellow, greasy & lobulated. Microscopically: tumour is formed of lobules of fat cells separated by delicate fibrous stroma. Fat cells appear as empty spaces with signet ring nuclei. Secondary changes: malignant change into liposarcoma is very rare.  3. Chondroma Definition: benign mesenchymal tumour of hyaline cartilage. Sites: Short bones of hand and feet. Flat bones as ribs, sternum, etc. Ends of long bones. Grossly: well defined, round or ovoid, capsulated mass. Cut section is bluish & lobulated. Microscopically: tumour is formed of lobules of hyaline cartilage separated by delicate fibrous stroma. Cartilage cells appear as empty spaces with central nuclei separated by bluish hyaline matrix Secondary changes: may turn into chondrosarcoma.  B. Muscle Tumours Leiomyoma Definition: benign mesenchymal tumour of smooth muscles. Sites: Uterus, is the most common site. May occur in wall of stomach, intestine & urinary bladder. Grossly: the following is the description of uterine myoma:  Number: single or multiple.  Site: subserous, submucous or intramural.  Size: from few mm to several cm.  Shape: round, ovoid or pedunculated.  Secondary changes: common.  Capsule: absent, there is a false capsule formed of compressed surroundings.  Consistency: firm.  Colour: grayish white.  Cut surface: whorly. Microscopically: tumour is formed of interlacing smooth muscle and fibrous tissue bundles. The muscle fibre is spindle-shaped with rod- shaped nucleus. The fibroblast is spindle-shaped with spindle-shaped nucleus. Secondary changes: common.  C. Vessel Tumours Capillary Haemangioma Cavernous Haemangioma Developmental malformation formed Developmental malformation formed of vascular channels full of blood. of vascular channels full of blood. Skin all over the body. Skin all over the body. Mucous membranes [lips & Mucous membranes [lips & tongue]. tongue]. Liver, kidney, spleen and brain Liver, kidney, spleen and brain Well defined, non-capsulated, Well defined, non-capsulated, slightly raised red area. It is raised and compressible red usually described as birth mark. area. In tongue  macroglossia. In lips  macrocheilia.  Capillary Haemangioma Cavernous Haemangioma Tumour is formed of small capillary Tumour is formed of large cavernous spaces lined by one layer of flat spaces lined by one layer of flat endothelial cells and filled with blood. endothelial cells and filled with blood. Stroma is delicate. Tumour is non- Stroma is delicate. Tumour is non- capsulated capsulated Capillary Lymphangioma Cavernous Lymphangioma Developmental malformation formed Developmental malformation formed of vascular channels full of lymph. of vascular channels full of lymph. Skin all over the body. Skin all over the body. Mucous membranes [lips & tongue]. Mucous membranes [lips & tongue]. Liver, kidney and spleen Liver, kidney and spleen Well defined, non-capsulated, slightly Well defined, non-capsulated, raised raised skin-coloured area. It is usually and non-compressible skin coloured described as birth mark. area. In tongue  macroglossia. In lips  macrocheilia  Capillary Lymphangioma Cavernous Lymphangioma Tumour is formed of small capillary Tumour is formed of large cavernous spaces lined by one layer of flat spaces lined by one layer of flat endothelial cells and filled with endothelial cells and filled with lymph. Stroma is delicate. Tumour is lymph. Stroma is delicate. Tumour is non-capsulated. non-capsulated. Malignant Tumours Carcinoma Sarcoma Malignant tumour of epithelial tissues. Malignant tumour of mesenchymal tissues. More common. Less common. Middle and old age Adolescents and young age Slower rate of growth. Faster rate of growth. Grows more by infiltration. Grows more by expansion. Does not form a bulky mass. Usually forms a bulky mass. Usually hard, rarely soft. Usually soft, rarely hard. [carcinos = crapes]. [sarc = flesh]. Either fungating, infiltrating, An apparently defined, non- malignant ulcer or annular capsulated fleshy mass. stricture. Reddish gray with more hge and Grayish white with less hge and excess necrosis. less necrosis. Groups of cells separated by Individual cells separated by stroma. stroma. Cells show less anaplasia. Cells show more anaplasia. Blood vessels are less in number Blood vessels are more in number and better formed. and poorly formed. Classified into well, moderately, poorly and Classified into differentiated and undifferentiated undifferentiated, according to cell arrangement. sarcoma, according to cell secretion. Slower spread Faster spread. Mainly by lymph. Rare and late by blood, except Mainly by blood. Ver rare by lymph. 122122111. S 0 : microscopic size. Usually not applicable. S I : confined to organ. S II : local removable spread. S III: fixed to surroundings. S IV : distant spread. TNM system: considers size of tumour, lymph node & distant spread.  Comparison Between Squamous and Basal Cell Carcinoma Squamous Cell Carcinoma Basal Cell Carcinoma Malignant epithelial tumour of stratified squamous Locally malignant epithelial tumour of the basal cell epithelium. layer. Skin all over the body. Skin of the face above a line extending from the angle Mucous membranes lined by stratified squamous of the mouth to lobule of ear, especially around angles epithelium. of eye, sides of nose and angles of mouth. Other mucous membranes after squamous metaplasia. Exposure to sunlight, carcinogens Exposure to sunlight, especially in irradiation and chronic irritation. white races due to ozone depletion. Polypoid mass: Begins as red papule then forms a depressed ulcer with Infiltrating mass: rough necrotic floor, rolled-in beaded edges and 3I. Malignant ulcer: 3 R + 3 I. Annular stricture. Dermis is infiltrated by masses Dermis is infiltrated by masses of malignant sq. cells [cell nests] of malignant basal cells [solid that tend to be arranged in same blue masses] that tend to show manner like the normal stratified peripheral palisade arrangement squamous epithelium. of the outer most layer. Outer layer basal cell-like. Middle layers polyhedral-like Central whorly masses of keratin [keratin pearls]. Cells show all features of Cells show all features of malignancy. malignancy Broder’s Grading System: Not applicable Grade I: 75%-100% of masses show keratin pearls. Grade II: 50%-75% of masses show keratin pearls. Grade III: 25%-50% of masses show keratin pearls. Grade IV: 00%-25% of masses show keratin pearls. Spread: Direct, lymph and blood. Spread: Direct only.  Glandular Carcinoma Definition: malignant epithelial tumour of glandular epithelium. Sites: all endocrine and exocrine glands, especially breast, stomach, intestine, liver, ovaries, etc…. Types: A. Adenocarcinoma: Definition: malignant tumour of glandular epithelium in which the tumour cells are arranged in acinar pattern. Sites: GIT, pancreas, endometrium, prostate, ovary, etc…. Grossly: polypoid mass, infiltrating mass or ulcerating mass [describe]. Microscopically: the tumour is formed of malignant acini lined by malignant cells. Malignant acini are variable in size and shape, lined by more one layer of cells and have irregular eccentric lumina. Malignant cells show… … …. Adenocarcinoma may function producing mucin, thyroxin, etc…. Secretion may distend the acini resulting in the formation of cystadenocarcinoma or papillary cystadenocarcinoma. B. Mucoid Carcinoma = Colloidal Carcinoma: Definition: malignant tumour of glandular epithelium in which the tumour cells produce excess mucin. Sites: GIT, breast and bronchi. Grossly: ill-defined noncpasulated soft jelly-like mass. Microscopically: the tumour is formed of malignant acini lined by malignant cells. The cells are distended with pale mucin and the nucleus is compressed at one side [signet ring appearance]. Sometimes acini rupture and malignant cells are separated by mucin lakes.  Carcinoma In Situ = Intra-epithelial Carcinoma Definition: early malignant changes in epithelial cells before invasion of the basement membrane [carcinoma stage 0]. Gross picture: difficult to be seen by the naked eye. Slight thickening may be seen. Microscopic picture: epithelial cells show loss of polarity, pleomorphism of cells and nuclei, hyperchromatism, increased N/C ratio, frequent mitosis, prominent nucleoli and may be tumour giant cells along the full thickness of the covering epithelium, but without invasion of the basement membrane. Fate: changes into invasive carcinoma after few years.  Types of Sarcoma 1. Fibrosarcoma: Definition: malignant mesenchymal tumour of fibrous tissue. Sites: Subcutaneous and submucous tissues. Intermuscular septa, fascia, ligaments. Fibrous stroma of any tissue as ovary, breast, etc. Grossly: an apparently-defined noncapsulated bulky, soft mass with areas of haemorrhage and necrosis. Microscopically: the tumour is formed of malignant spindle-shaped fibroblasts with spindle-shaped nuclei separated by collagen bundles. The cells show… …. 2. Leiomyosarcoma: Definition: malignant mesenchymal tumour of smooth muscles. Sites: Uterus mainly. Wall of GIT and Wall of urinary bladder, etc. Grossly: an apparently-defined noncpasulated bulky, soft mass with areas of haemorrhage and necrosis. Microscopically: the tumour is formed of malignant spindle-shaped leiomyoblasts with rod- shaped nuclei separated by scanty stroma. The cells show… ….  Locally Malignant Tumours Definition: group of malignant tumours that spread only locally. Characterized by:  Relatively slow rate of growth.  Microscopic features of malignancy.  Local spread only. No lymph or blood spread. Examples include:  Basal cell carcinoma: skin. Craniopharyngioma: base of skull  Osteoclastoma = giant cell tumour: bone Carcinoid tumour: GIT.  Adamantinoma: mandible Astrocytoma [grade II] : CNS  Pigmented Tumours Benign Melanoma of Skin = Naevus = Mole Definition: benign tumour of melanocytes. It is considered as hamartoma since it is present since birth and stops growth after puberty. Gross picture: single or multiple, small [rarely large] flat or slightly raised lesions. Colour ranges from light brown to black. Surface may show hairs. Microscopic picture: noncapsulated lesion, formed of round to oval naevus cells collected in small groups and contain variable amount of melanin. The position of naevus cells varies according to type: Junctional naevus: naevus cells are located in the lower most part of epidermis at the dermo-epidermal junction. It does not turn malignant. Intradermal naevus: naevus cells are located in the upper part of dermis. The covering epidermis may show hyperplasia or atrophy. It does not turn malignant. Compound naevus: naevus cells are located both in the lower most part of epidermis at the dermo-epidermal junction & in the upper part of dermis. May turn malignant. Malignant Melanoma of Skin May arise de novo or on top of a benign melanoma. The following signs point to malignant change of a benign melanoma:  Rapid changes in rate of growth.  Rapid change of colour.  Surface ulceration and bleeding on touch.  Fixation and induration.  Loss of hair [in hairy naevus].  Enlargement of draining lymph nodes. 4. Nodular malignant melanoma: Arises any where in the form of dark brown ulcerating nodule. Microscopic picture: malignant melanocytes with excess intracellular and extracellular melanin. Cells may be arranged in small groups separated by stroma [melano-carcinoma] or singly scattered cells separated by stroma [melano-sarcoma]. Cells show … … …. Spread: direct, lymphatic and blood. Excess melanin may appear in blood [melanaemia] and may filter in urine [melanuria].  Teratoma Definition: composite tumour formed of tissues derived from ectoderm, mesoderm and endoderm. Tissues of teratoma are foreign to tissue of origin [abnormally arranged abnormal structures]. Origin: derived from: Germ cells of ovary and testis. Totipotent cells that escape the effect of primary organizer. Sites: ** Common sites: Ovary and testis. ** Rare sites: base of skull, mediastinum, retro-peritoneum and sacroccocygeal region.  Hamartoma Definition: developmental tumour-like malformations characterized by: They are present since birth. Stop growth at puberty. Non capsulated. Formed of abnormally arranged normal structures, not foreign to tissue of origin. They include: All haemangiomas All osteomas. All benign melanomas. Neurofibroma. Lung [bronchial] hamartoma and kidney hamartoma.  Prognosis in Malignant Tumours Depends upon the following factors: 1. Type of tumour: malignant melanoma has a poor prognosis than squamous cell carcinoma. 2. Tumour stage: the extent of local and distant spread are the most important factors. 3. Tumour grade: well differentiated tumours have a better prognosis. 4. Host-immune response: patient with immunodeficiency have very poor prognosis. 5. Tumour radiosensitivity: radio-sensitive tumours have a better prognosis. 6. Other factors: age, anatomical site and duration.