Filiform polyposis represents a rare but recognised manifestation on the varied spectrum of histopathology in colonic tuberculosis. We report a case of filiform polyposis secondary to colonic tuberculosis presenting as colo-colonic intussusception diagnosed on an abdominal computed tomography (CT) scan. The patient required urgent hemicolectomy and defunctioning ileostomy. Examination of the resected bowel lesions revealed filiform polyposis. Induced sputum samples from the patient grew
Diagnosing colonic tuberculosis may present many challenges in practice. In general, gastrointestinal tuberculosis may have wide variation in presenting complaint, pattern of distribution of lesions, gross macroscopic appearance of lesions, and histological findings [
A 44-year-old previously fit and well Caucasian man presented with a one-day history of severe, unremitting, and diffuse colicky abdominal pain with absolute constipation. He had a four-month history of similar but less severe pain, preceded by loose stools with mucus and frequent PR bleeds on a background of poor appetite and 7 kg weight loss over six months. Family history was notable for colorectal cancer in his uncle at 71 years of age. Social history was significant for 10 cigarettes a day, 70 units of alcohol a week, and extensive travel history to Thailand. On examination, the lower abdomen was distended and diffusely tender with tinkling bowel sounds but no guarding or rigidity.
A plain supine abdominal radiograph showed a hugely dilated caecum (maximum diameter: 15 cm) and transverse colon (maximum diameter: 10 cm) with paucity of gas in the descending colon (Figure
Abdominal X-ray at presentation showing hugely dilated caecum and transverse colon with paucity of gas in the descending colon.
CT scan of abdomen (coronal section) showing intussusception of a polypoid lead point (
CT scan of chest (coronal section) showing bilateral cavitating lesions in the lung apices (indicated by arrows).
An urgent exploratory laparotomy revealed an irregular mass in the distal transverse colon and another adjacent mass in the splenic flexure with apparent spontaneous resolution of the intussusception seen on CT. Widespread lymphadenopathy was noted in the transverse colon mesentery. A left hemicolectomy was undertaken with excision of the left-sided omentum, followed by a side-to-side anastomosis with a defunctioning loop ileostomy.
A Mantoux test yielded 16 mm induration, albeit in the context of prior BCG vaccination 30 years ago. However, alcohol and acid-fast bacilli (AAFB) were not detected in sputum samples. HIV test was negative.
Histology sections from the colonic lesion showed an area of florid filiform polyposis (Figure
Section from left hemicolectomy showing a constricting mass in the distal transverse colon (Label A) and an adjacent synchronous mass in the proximal descending colon (Label B). Filiform polyps (F) are seen within both lesions.
H&E histology slide 50x magnification showing subserosal lymphoid aggregates in a rosary pattern. S = serosa,
Despite the absence of AAFB on sputum microscopy and colonic histology, the Infectious Disease (ID) team treated the patient empirically for tuberculosis on a 6-month course of rifampicin (10 mg/kg/day up to 600 mg/day), isoniazid (5 mg/kg/day up to 300 mg/day), pyrazinamide (30 mg/kg/day up to 2 g/day), and ethambutol (15 mg/kg/day) on the basis of the cavitating lung lesions and positive Mantoux test. The patient recovered and was discharged from hospital a week later.
Serial sputum cultures eventually grew fully sensitive
Filiform polyposis is a rare entity that is most often encountered in the colon of patients with a history of inflammatory bowel disease (IBD) [
Diagnosing colonic tuberculosis may present many challenges in practice. Colonic tuberculosis can often mimic IBD, in particular Crohn’s disease. Macroscopically, colonic tuberculosis can result in IBD-like lesions such as segmental ulcers, generalised colitis, mucosal nodules, polyps, strictures, perforation, and fistulae [
The histopathology of colonic tuberculosis may, however, represent a varied spectrum rather than a well-defined entity. Multiple biopsy samples may confirm granulomas that are typically located in the submucosa [
It is important to note that prior BCG vaccination in childhood does not preclude the development of subsequent tuberculosis. In a meta-analysis of BCG vaccine trials, BCG vaccination showed an overall 86% efficacy in protecting against miliary and meningeal tuberculosis and only heterogeneous efficacy against pulmonary tuberculosis [
In our patient, his travel history, cavitating pulmonary lesions, and multiple segmental colonic involvement were all suggestive of tuberculosis. Although his colonic histology showed nonspecific inflammatory features with absence of AAFBs and granulomas,
In conclusion, this case illustrates filiform polyposis as a rare but recognised manifestation on the varied spectrum of histopathology in colonic tuberculosis. This case also highlights the difficulties in diagnosing colonic tuberculosis and the importance of initiating early anti-tuberculous treatment in patients with a high index of suspicion for tuberculosis despite negative histology and/or microbiological culture.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors thank Dr. Arun Gupta, Consultant Radiologist, St. Mark’s Hospital, for his opinion on the radiological images in this case.