A 23-year-old male presented with mild intermittent peri-umbilical pain and low-grade fever for 3 months. There was a history of loss of appetite and weight loss (4 kg over 3 months). The patient's bowel and bladder habits were normal. There was no significant medical or surgical history.
On examination, the patient's vitals were stable and his physical examination was normal except for a well-circumscribed, non-tender mass, about 5 x 5 cm in size, which was palpable in the infra-umbilical area. A routine hemogram, serum biochemistry, liver function, and renal function tests were within normal limits. A chest X-ray revealed no abnormality. Urinalysis revealed occasional pus cells, but the culture was sterile.
Contrast-enhanced computed tomography (CT) of the abdomen was suggestive of a smooth-walled, cystic mass measuring 5 x 5 x 6 cm, located above the bladder (Fig. 1). Fine-needle aspiration cytology revealed necrotic material.
With a clinical diagnosis of an urachal abscess, surgical excision was planned. At surgery, the mass was located in the pre-peritoneal space, just above the bladder. It was filled with white pultaceous material. With gentle blunt and sharp dissection, the mass was separated from the bladder and could be excised en bloc (Fig. 2).
On histopathological examination, urothelium was found along with multiple granulomas, caseation, and epitheloid and Langhans cells, suggestive of urachal tuberculosis (Fig. 3). On the basis of these results, the patient was started on combination anti-tubercular therapy with rifampicin, isoniazid, ethambutol, and pyrazinamide, which were given for 2 months.
Culture of the pultaceous material on Lowenstein-Jensen media confirmed the presence of Mycobacterium tuberculosis; the bacilli were sensitive to isoniazid, rifampin, and ethambutol. Blood, sputum, and urine cultures performed three times during the post-operative period were sterile.
The patient was then continued on a combination of rifampicin and isoniazid for 4 months, according to national guidelines. The patient completed the treatment and is doing well. Follow-up CT of the abdomen after the completion of anti-tubercular treatment revealed no evidence of disease.