Specialespecifikt kursus i Patologisk Anatomi 2009: Fordøjelseskanalens patologi APPENDIX

Appendix Occurrence of lesions (%) Acute appendicitis 72 Normal 16 Fibrosis 3 (Cyst-)Adenoma 3 Diverticulitis 2 Periappendicitis 1 Hyperplastic polyp 1 Chronic appendicitis 1 Metastatic carcinoma 1 Carcinoid tumour 0.4 Endometriosis 0.3 Granulomatous inflam. 0.2 Adenocarcinoma 0.1 Aalborg 1993-2002: ~ 4,400 elective appendectomies Primary diagnosis only

Appendix - examination Lenght Normal: 5 12 cm (2 20) Diameter Normal: ~ 0.7 cm Serosal and cut surface Discoloration and exsudate Diverticula Tumor Fecalith

Appendix - examination Alternating longitudinal and transverse sections

Appendix - examination

Idiopathic acute appendicitis Life time risk: 5% Peak age: 10-25 y Range: From neonatal to ancient Pathogenesis: Luminal obstruction infection Fecalith, food fragments, lymphoid hyperplasia, tumour

Gross: hyperaemia fibrinopurulent ex. black pus in lumen ectatic lumen ulceration perforation

Idiopathic acute appendicitis Histology (classic) Erosion Crypt abscesses Ulceration Mucosal neutrophilic infiltration Transmural neutrophilic infiltration Myocytolysis

Idiopathic acute appendicitis Acute superficial Acute (NOS) Acute phlegmonous Acute necrotitizing Gangrene

Complications of acute appendicitis Perforation 25% (higher in young and old) Periappendiceal absces 5% Pylephlebitis Hepatic absces

Protracted inflammation Resolution Crypt distortion Chronic inflammation Granulomatous inflammation Submucosal fibrosis Luminal obliteration Neuronal hyperplasia

Appendix diverticulitis 90% of diverticuli acquired Often secondary to luminal obstruction Often multiple Localized inflammation Early perforation Older patients Protracted course

Appendix infections Bacterial infections Yersinia spp. Salmonella Shigella Campylobacter Actinomyces Viral infections Morbilli Parasitic infections Enterobius vermicularis

Appendiceal infections Enterobius

Appendiceal infections Yersiniosis

Appendix Chronic inflammatory bowel disease Crohn s disease 25-50% of Crohn s patients have granulomas in appendix <5% of granulomatous appendix have Crohn s disease Isolated appendiceal Crohn s disease dubious entity! Ulcerative colitis may appear without right colon involvement!

Appendix endometriosis & endosalpingiosis MLH1 MSH2

Hyperplastic polyp of appendix Varying from small to involving the whole mucosa Normal nuclei No stratification

Appendix tubular adenoma Rare Associated with colon adenomas and FAP

Appendix tubular adenoma

Appendix villous adenoma Female preponderance (20-) 60 80 y Gross: Mucosal thickening, mucocele Histology: Diffuse mucosal involvement Cystadenoma Complication: Pseudomyxoma peritonei

Appendix villous adenoma

Appendix villous adenoma & pseudomyxoma

Appendix villous adenoma & pseudomyxoma appendix serosa CK20 bladder wall

Appendix villous adenoma & pseudomyxoma

Appendix adenocarcinoma Classic colon like adenocarcinoma cystadenocarcinoma Goblet cell carcinoid = crypt cell carcinoma Signet ring cell carcinoma Complication: Pseudomyxoma peritonei

Appendix adenocarcinoma

Appendix adenocarcinoma MLH1 MSH2

Appendix mucocele Etiology Hyperplastic polyp Villous adenoma Adenocarcinoma

Appendix other neoplasms: B-cell lymphoma MLH1 T-cell rich B-cell lymphoma MSH2 IgKappa