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33 Cards in this Set
- Front
- Back
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How do Proximal Colon Tumours Exist? |
Polypoid exophytic masses Rarely obstruct lumen Invasion of bowel walls as firm, white serosal or subserosal masses |
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How do Distal Colon Tumours Exist? |
Annular encircling growth pattern/lesion 'NAPKIN RING CONSTRICTION' Irregular, beaded, heaped borders with ulcerated, necrotic centre Often markedly narrowed lumen with prox. distended segment Again, invade bowel wall as firm, white serosal or subserosal masses |
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How do colon tumours appear on radiology? |
Ba enema (with air via rectum) + X-ray 'Apple-core' lesion |
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Histology of Colorectal Carcinoma |
Tall columnar cells (like Adenocarcinoma) to disordered anaplastic masses Many cells produce mucin INVASIVE TUMOUR = STRONG DESMOSPLASTIC STROMAL RESPONSE > FIBROSIS |
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How do RIGHT-sided Colorectal Carcinoma's present? |
Fatigue Weakness IRON-DEFICIENCY ANAEMIA |
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What's the significance of Fe-Deficiency anaemia? |
IN AN OLDER MALE, GI CANCER TIL PROVEN OTHERWISE |
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How do LEFT-sided colorectal carcinomas present? |
Crampy LLQ pain, altered bowel habit & OCCULT BLOOD |
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What are the systemic manifestations of Colorectal carcinoma? What do they indicate? |
Malaise, weight loss, weakness Indicate more advanced/extensive disease |
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How do colorectal tumours spread? |
All eventually invade adj structures Spread to distal structures via lymphatic & blood vessels Common sites of metastases: Liver, Bone, Lung, Serosal Layer of Peritoneal Cavity, Brain, Local lymph nodes |
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What staging is used for Colorectal carcinoma? |
Dukes' Staging A = Confined to muscle or submucosa - 90%+ 5-year survival B = Spread through muscle layer, but no lymph node involvement - 70% + 5-year survival C = Lymph node involvement = 35% 5-year survival |
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What is the origin of carcinoid tumours |
Endocrine cells |
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Where do Carcinoid tumours occur? |
SI - Mainly Ileum Stomach, Colon, Rectum MAINLY APPENDIX |
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Who is most often affected by Carcinoids? |
Over 60's |
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What is aggressive behaviour of Carcinoids associated with? |
Location of origin Size Depth of local penetration Histological features of necrosis & mitosis |
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What type of lesions are Carcinoids? |
Often lone lesions BUT MULTICENTRIC IN ILEUM & STOMACH |
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How common are Carcinoids? |
2% Colorectal Malignancies Nearly 1/2 of SI malignancies |
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What is the macroscopic appearance of Carcinoids |
Polypoid or plateau-like lesions <3cm (raised by Intramural or submucosal masses) SOLID YELLOW-TAN APPEARANCE ON TRANSECTION |
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Histological Appearance of Carcinoids |
Neoplastic cells form discrete islands, stands, glands, trabeculae & undifferentiated sheets Tumour cells monotonously similar with pink & granular cytoplasm & round-oval stippled nuclei Electron Microscopy shows membrane-bound secretory granules with cytoplasmic dense-core granules |
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Do Carcinoids cause local symptoms? |
Rarely Associated with angulation or stricture of SI |
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What is Carcinoid Syndrome? |
Excess Serotonin - 5,HT First sign = Cyanosis Cutaneous flushing Cramps, diarrhoea, N/V Cough, Wheeze, Dyspnoea |
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What Carcinoids Metastasise? Which don't? |
Appendix & RECTAL carcinoids don't metastasise 90% of gastric, ileal & colonic carcinoids that have penetrated half of the muscle layer, have spread to distal likes like liver & lymph nodes @ time of diagnosis |
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Prognosis for Carcinoids? |
90% 5-year survival Sensitive to radio- & chemotherapy |
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What are GI Lymphomas? |
Show no signs of Mediastinal lymph node, liver, spleen, bone marrow involvement @ time of diagnosis B-Cell & T-Cell Lymphomas |
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What are B Cell Lymphoma Classes? |
Burkitt's Lymphoma Immunoproliferative SI Disease (IPSID) - Mediterranean Lymhpoma Mucosa-Ass. Lymphoid Tissue - MALT Lymphoma 55-60% MALT Lymphomas in stomach |
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What is prognosis for B cell lymphoma? |
85% 10-year survival with localised mucosal or submucosal disease |
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T cell Lymphoma Prognosis & Association |
11% 5-year survival Associated with long-standing malabsorption syndrome |
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Mesenchymal Tumours of Colon & Rectum |
Arise from stroma Lipoma Leiomyoma Leiomyosarcoma |
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Describe Lipoma |
Well-demarcated, small firm nodules, <4cm from muscularis propria or submucosa |
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Describe Leiomyosarcoma |
Large, bulky intramural mass As big as footballs, or pregnancy-like Eventually fungates & ulcerates into lumen or subserosally into abdominal |
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Prognosis for Leiomyosarcoma |
50-60% 5-year survival |
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Lining of anal canal |
Upper 1/3 = Rectal mucosa Middle 1/3 = Transitional Lower 1/3 = Stratified Squamous |
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Most common benign neoplasm of anus |
Warts - condyloma acuminata Often caused by HPV |
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Malignant CARCINOMAS of Anal Canal |
Basaloid Pattern - Immature proliferative cells from basal layer of stratified sq. epithelium Adenocarcinoma of Anal Canal = Extension of rectal adenocarcinoma Malignant Melanoma = V rare Squamous Cell Carcinoma = Ass. with Chronic HPV infection |
