Psoas Abscess Secondary to Renal Tuberculosis in a Middle-aged Woman
A 45-year-old woman presented with dull aching abdominal pain in the right upper quadrant over the past 2 months. The pain was vague in character and nonradiating. She did not complain of fever or chills. There were no gastrointestinal or urological complaints. She had a history of mycobacterial cervical lymphadenitis in her twenties, which had been treated with antituberculous medications for 2 years.\nHer initial blood pressure was 120/70 mmHg and her body temperature was 36.6℃. A physical examination revealed a palpable mass in the right upper quadrant below the lower costal margin without obvious tenderness. No costovertebral angle tenderness was elicited. Initial hematological and biochemical tests showed no remarkable findings, except a decreased hemoglobin level (10.9 g/dL). Neither pyuria nor hematuria was shown in the urinalysis.\nAbdominal plain radiography showed extensive lobulated calcifications on the right renal shadow, suggestive of a tuberculous kidney (). Abdominal computed tomographic (CT) scan better demonstrated calcifications of the right kidney, right upper ureter, and retroperitoneal lymph nodes. There was no functioning parenchyma in the right kidney, and the dilated calyceal spaces were filled with low-attenuation contents. These abscess-like intrarenal collections extended to the right psoas muscle through the right posterior pararenal space. A CT scan showed apparent thick-walled collections measuring 6 cm×4 cm×8 cm in the right psoas muscle (). A percutaneous catheter was placed in the right posterior pararenal space to obtain contents for culture and to drain the abscess. A purulent, light gray material was drained from the catheter; however, no acid-fast bacilli were seen in the pus, and the pus culture yielded no bacteria. The results of polymerase chain reaction (PCR) for Mycobacterium tuberculosis in the pus were also negative. The patient was explored and subjected to a right nephrectomy to surgically remove the infectious source. The remaining psoas abscess, which had degenerated into a hard mass, was also removed. The histopathological examination of the nephrectomized specimen and the specimen from the remaining psoas abscess revealed chronic granulomatous inflammation with caseous necrosis, consistent with tuberculosis (). No acid-fast bacilli were detected by Ziehl-Neelsen staining of the specimens. Postoperatively, the patient took antituberculous drugs for 6 months. The patient is now asymptomatic at 2 years of follow-up.