GIT-9Miscellaneous

Dr.CSBR.Prasad, M.D.,

Hemorrhoids

• Variceal dilations of the anal and perianal venous plexuses form collaterals that connect the portal and caval venous systems

• Affect about 5% of the general population Causes:– PHT– Constipation (straining at stool)– Venous stasis of pregnancy

Types

• External hemorrhoids: Dilatation of collateral vessels within the inferior hemorrhoidal plexus [located below the anorectal line]

• Internal hemorrhoids: those that result from dilation of the superior hemorrhoidal plexus within the distal rectum

Hemorrhoids

Histology

• Thin-walled, dilated, submucosal vessels that protrude beneath the anal or rectal mucosa

• They are subject to trauma:– Inflammation– Thrombosis– Superficial ulceration

Thin-walled, dilated, submucosal vessels

Thin-walled, dilated, submucosal vessels

Clinical Features

• Pain• Rectal bleeding– Hematochezia

Tumors of the Anal CanalThree types of epithelia lines the anal canal– Upper ⅓ - Columnar type of epithelium– Middle ⅓ - Transitional epithelium / Cloacogenic– Distal ⅓ - Stratified squamous epithelium

Carcinomas:– Adenocarcinoma– Cloacogenic – Transitional cell carcinoma / Basaloid– Squamous cell carcinoma

• HPV associated• Precursor lesion: Condyloma accuminatum

– Mixed carcinomas

Ca. Anal canal

Squamous cell carcinomaSquamous cell carcinoma

AdenocarcinomaAdenocarcinoma

Basaloid (Cloacogenic) CarcinomaBasaloid (Cloacogenic) Carcinoma

Cloacogenic tumor H&E 200x

Basaloid (Cloacogenic) CarcinomaBasaloid (Cloacogenic) Carcinoma

Positive staining with HMWCK in tumor cells (HMWCK antibody), ×200

Paget’s disease of the perianal skinPaget’s disease of the perianal skin

Buschke–Löwenstein tumour

Acute AppendicitisAcute Appendicitis

• Most common in adolescents & young adults• Males• DDs:• Mesenteric lymphadenitis• Acute salpingitis• Ectopic pregnancy• Mittelschmerz • Meckel diverticulitis

Pathogenesis:•Progressive increases in intraluminal pressure that compromise venous outflow– Fecalith– Gall stones– tumor – Mass of worms

•Ischemic injury and stasis of luminal contents:– Favor bacterial proliferation– Trigger inflammatory responses

Fecalith

Morphology• Congested serosal blood vessels• Normal glistening serosal surface turns into a dull, granular

and erythematous• Hall mark of Acute appendicitis:

• Diagnosis of acute appendicitis requires neutrophilic infiltration of the muscularis propria

• Other features:• Mucosal ulceration• Luminal exudation• Fibrinopurulent exudate on the serosa

• Acute suppurative appendicitis• Acute gangrenous appendicitis

Hall mark of Acute appendicitis:Diagnosis of acute appendicitis requires neutrophilic

infiltration of the muscularis propria

Clinical Features• Pain:– Early acute appendicitis: Periumbilical – Later: Localizes to the right lower quadrant

• Classic physical finding is McBurney's sign• Complications of appendicitis:– Perforation– Pyelophlebitis– Portal venous thrombosis– Liver abscess and – Bacteremia

Tumors of the AppendixCarcinoidCarcinoid

• The most common tumor of the appendix is the carcinoid

• Usually discovered incidentally • Usually involves the distal tip of the appendix• 2 to 3 cm in diameter• Nodal metastases are infrequent, and distant

spread is rare

Carcinoiod of appendix

Carcinoid of appendix

Carcinoid of appendix

Carcinoid of appendix

Tumors of the AppendixOthersOthers

• Mucocele• Mucinous cystadenoma – Pseudomyxoma peritoneii

• Mucinous cystadenocarcinoma

Mucocele from mucinous cystadenoma of the appendix

Pseudomyxoma peritonei

Peritoneal disease

Inflammatory DiseasePeritonitis may result from bacterial invasion or chemical irritation and is most often due to: •Leakage of bile or pancreatic enzymes, which produces sterile peritonitis – Perforation or rupture of the biliary system– Acute hemorrhagic pancreatitis

•Foreign material•Endometriosis•Ruptured dermoid cysts •Perforation of abdominal viscera

TumorsTumorsPrimary tumors: •Mesotheliomas – Asbestos exposure

•Desmoplastic small round cell tumor (DSCRT)– t(11;22)(p13;q12)

Secondary tumors: quite common•Ovarian adenocarcinoma•Pancreatic adenocarcinoma•Gastric carcinoma •Appendiceal mucinous carcinomas •Wide variety of tumors of extra-abdominal origin

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