A Rare Case of Intestinal Tuberculosis with Chronic Partial Small Bowel Obstruction in a 37-Year-Old Ethiopian Man

Tuberculosis (TB) is a chronic granulomatous inflammatory disease that affects any part of our body. TB is a significant problem in developing countries. Intestinal TB accounts for 2% of TB cases worldwide. Terminal ileum and cecum are the two commonly affected regions because of abundant lymphoid tissue, physiologic stasis, limited digestive activity and increased fluid and electrolyte absorption rate. Intestinal obstruction is the leading complication of intestinal TB, and it occurs because of intestinal luminal narrowing, multiple strictures or adhesions. The clinical presentation of patients with intestinal TB and post-TB intestinal obstruction is non-specific. It can be acute, chronic, or acute on chronic. Uncomplicated cases of intestinal TB can be managed medically. Surgery is reserved for complicated cases of intestinal TB, which includes peritonitis, intestinal obstruction and perforations. Here, we present a 37-year-old man who presented with long-standing, intermittent crampy abdominal pain and vomiting. He was diagnosed with chronic partial small bowel obstruction secondary to possibly small bowel carcinoma. We did segmental ileal resection and end-to-end ileo-ileal anastomosis. Postoperatively, the histopathology result turned out to be intestinal TB. This case report aims to make physicians aware of the rare condition of small bowel obstruction secondary to intestinal TB. Clinicians need to have a high index of suspicion in any patient with long-standing symptoms of partial obstruction and consider surgery and anti-TB once diagnosed.

Recent updates in diagnosis of abdominal tuberculosis with emphasis on nucleic acid amplification tests

INTRODUCTION

Abdominal tuberculosis (TB) is a common epitome of extrapulmonary TB (EPTB), wherein peritoneal and intestinal TB are the most prevalent forms. Diagnosis of abdominal TB is a daunting challenge owing to variable anatomical locations, paucibacillary nature of specimens and atypical clinical presentations that mimic other abdominal diseases, such as Crohn's disease and malignancies. In this review, we made a comprehensive study on the diagnosis of abdominal TB.

AREA COVERED

Various modalities employed for abdominal TB diagnosis include clinical features, imaging, bacteriological tests (smear/culture), histopathological/cytological observations, interferon-gamma release assays and nucleic acid amplification tests (NAATs). Among NAATs, loop-mediated isothermal amplification assay, PCR, multiplex-PCR, nested PCR, real-time PCR and GeneXpert® MTB/RIF were discussed. Identification of circulating Mycobacterium tuberculosis cell-free DNA by real-time PCR within ascitic fluids is another useful approach.

EXPERT OPINION

Several novel molecular/immunological methods, such as GeneXpert Ultra, aptamer-linked immobilized sorbent assay, immuno-PCR (I-PCR) and nanoparticle-based I-PCR have recently been developed for detecting pulmonary TB and several EPTB types, which may also be explored for abdominal TB diagnosis. Precise and prompt diagnosis of abdominal TB may initiate an early therapy so as to reduce the complications, i.e. abdominal pain, ascites, abdominal distension, intestinal obstruction/perforation, etc., and avoid surgical involvement.Plain Language SummaryAbdominal tuberculosis (TB) is a manifestation of extrapulmonary TB (EPTB), where peritoneal and intestinal TB are two major forms. Diagnosis of abdominal TB is difficult owing to low bacterial load present in clinical samples and non-specific clinical presentations as it mimics other diseases such as inflammatory bowel diseases, abdominal malignancies, etc. Bacteriological tests (smear/culture) almost fail owing to poor sensitivities and it is not always possible to get representative tissue samples for histopathological and cytological observations. In recent years, molecular tests i.e. nucleic acid amplification tests (NAATs), such as PCR/multiplex-PCR (M-PCR), nested PCR and GeneXpert are widely employed. Markedly, PCR/M-PCR and nested PCR exhibited reasonable good sensitivities/specificities, while GeneXpert revealed low sensitivity in most of the studies but high specificity, thus it could assist in differential diagnosis of intestinal TB and Crohn's disease. Further, novel molecular/immunological tests employed for pulmonary TB and other EPTB types were described and those tests can also be utilized to diagnose abdominal TB. Reliable and rapid diagnosis of abdominal TB would initiate an early start of anti-tubercular therapy and reduce the severe complications.