King Edward Memorial Hospital - Departments: Radiology

Radiology

Case of the Month

Case No. :	05
Month :	May
Year :	1999
Contributor :	Dr. Rina Dhakappa

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Case History | Diagnosis | Discussion | Radiological Findings

Case History
Diagnosis
Discussion
Radiological Findings

Case History :

A 27 years old man presented with a three months history of generalized abdominal pain and weight loss of 6 kgs. Clinical examination revealed a firm, non-tender lump in the right iliac fossa. Laboratory investigations were non-contributory except for raised erythrocyte sedimentation rate (ESR: 65mm/hr). Chest radiograph was normal. Double contrast barium enema
( Fig 1, Fig 2, Fig 3 ) was performed to characterize the right iliac fossa lump.
This study demonstrates a circumferential narrowing over a 5 cm long segment of the proximal ascending colon with "shouldering" and mucosal irregularity. There is marked dilatation of the terminal ileum and its terminal most portion appears to be narrowed. The cecum is "spastic".

Exploratory laparotomy revealed a hard mass in the cecum, ascending colon and surrounding the terminal ileum with dilatation of the terminal ileum.The rest of the colon was normal. A right hemicolectomy with ileo-transverse anastomosis was performed. Histopathological examination of the resected specimen showed caseating granulomas. However, acid fast bacilli were not identified. However, Lowenstein-Jensen culture grew Mycobacterium tuberculosis, thus providing conclusive proof of tuberculous etiology. The patient received four drug anti-tuberculous chemotherapy for six months. The patient has been asymptomatic for the last nine months.


Fig 1	Fig 2	Fig 3

Diagnosis :

Ileo cecal and proximal colonic tuberculosis.

Discussion :

The gastrointestinal tract is a common site of extrapulmonary tuberculosis. It commonly affects young adults in the second and third decades. There is a marked female preponderance. Small bowel is the commonest site of affection in gastrointestinal tuberculosis. Colonic tuberculosis occurs in 3% of patients with intestinal TB.
Mycobacterium tuberculosis is the most common offending organism. Gut TB due to M. bovis has considerably decreased in incidence with the introduction of pasteurisation of milk. The GI tract is affected by tuberculosis secondary to swallowing of infected sputum (25% of patients with GI TB have pulmonary TB), infected milk or due to lympho-haematogenous spread. Following the entry of mycobacteria into the tubular mucosal glands of the colon, ulceration may occur. The ulcers may become confluent and circumferential and a girdle ulcer with undermined edges can develop, which then undergoes fibrosis producing a stricture, thereby mimicking an annular carcinoma.
Most patients of colonic tuberculosis present with abdominal pain and subacute intestinal obstruction. The various pathologic processes produced by the Mycobacteria give rise to various radiologic patterns of affection seen in colonic TB.
The patterns of affection of colonic TB have been classified according to the barium enema appearances into three broad groups; hyperplastic, ulcerative and ulcero-hyperplastic. Tuberculosis at times masquerades as malignancy.

Radiological Findings :

There may be shallow ulcers with elevated margins seen as fine collections of barium, sometimes presenting a stellate appearance. These ulcers are frequently arranged perpendicularly to the colonic longitudinal axis. Girdle ulcers may be seen as short and symmetrical circular stenosis. Small ulcers and polyps may be seen on the mucosal surface of the stenoses. Deformed and retracted cecum is usually accompanied by a fixed, irregular and frequently gaping and incompetent ileocaecal valve producing the Fleischner sign and the Steirlin's sign with a coned cecum..
Colonic tuberculosis may be long (> 5 cm) or short segment. Long segment affection always affects the IC region. Synchronous segmental affection of the colon is not uncommon. Short segment strictures are most commonly situated around the hepatic flexure. They are circumferential and have a longitudinal funnelling narrowing distally. Inflammatory polypi are at times seen in colonic TB. The ulcerations are circumferential or of the girdle type.
Associated involvement of the ileo-cecal region is usually present (as in the present case) and this association may serve as a useful pointer in differentiating tuberculosis from malignancy and other diseases of the colon such as- Crohn's disease, ulcerative colitis, ischaemic colitis, amebiasis and malignancy.
Colonic tuberculosis has to be entertained in the differential diagnosis of isolated colonic pathology in the presence of raised ESR, documented past history of tuberculosis, radiological evidence of associated ileo-cecal affection.
A patient with small bowel TB will present with pain, vomiting, constipation, sensation of a lump in the abdomen, diarrhea or malabsorption. The complications include obstruction, perforation, abscess, intussusception or massive GI hemorrhage.
It is important to differentiate colonic TB from Crohn's colitis. Anal involvement and internal fistulae are more common in Crohn's disease, while free perforation is more common in TB. The ulceration in TB is circumferential, while that in Crohn's is along the mesenteric border.