Molecular diagnosis of an unusual aetiology of chronic abdominal pain with ascites.

An immigrant woman in her 60s with a complex medical history and remote occupational exposure to patients with tuberculosis (TB) presented with abdominal pain, early satiety, bloating and weight loss. Physical exam showed abdominal distention and ascites. Diagnostic paracentesis revealed low serum ascites albumin gradient and elevated ascitic lymphocytic count. However, fluid cytology, bacterial and mycobacterial cultures were negative. An interferon-gamma release assay for TB was indeterminate. MRI of the abdomen and pelvis showed a thickened endometrial stripe. Endometrial biopsy demonstrated non-caseating granulomatous endometritis. No organisms were identified on Grocott methenamine silver or acid-fast bacilli special stains. A tissue block from the endometrial biopsy submitted for DNA sequencing was positive for mycobacterium tuberculosis (MTB) complex Urine mycobacterial cultures were obtained and the patient was started on isoniazid, rifampin, ethambutol and pyrazinamide, with significant improvement in her symptoms. Urine mycobacterial cultures were eventually positive for pansusceptible MTB.