Primary Tuberculous Intramuscular Abscess in a Diabetic Elderly Male: An Unusual Case Report

Tuberculosis (TB) primarily affects the lungs, but extrapulmonary manifestations, such as musculoskeletal TB, account for 15-20% of cases. Isolated intramuscular TB abscesses are exceedingly rare cases of extrapulmonary TB. Predisposing factors, such as diabetes mellitus, immunosuppression, and advanced age, increase the risk of such atypical presentations. This report presents a rare case of a primary tuberculous intramuscular abscess in an elderly diabetic male, emphasizing diagnostic challenges and the importance of a multidisciplinary approach.

A 63-year-old male with uncontrolled type 2 diabetes presented with a 2-month history of right thigh pain and progressive swelling. Examination revealed an 8×9 cm, nontender, firm lump in the right thigh with normal overlying skin. Imaging with 3T MRI showed a multilobulated fluid collection in the thigh's upper third region, predominantly in the adductor and anterior compartments, with surrounding muscle edema and multiple enlarged inguinal lymph nodes. Histopathological examination of drained material revealed caseating granulomas with Langhans giant cells, consistent with tuberculosis. CBNAAT confirmed rifampicin-sensitive Mycobacterium tuberculosis. The patient was diagnosed with a primary tuberculous abscess and initiated on a 6-month antituberculosis therapy. He showed significant clinical improvement at the 1-month follow-up and successfully completed his 6-month ATT without any intolerance.

This case underscores the importance of considering TB in atypical presentations, particularly in endemic regions and high-risk populations. Prompt diagnosis through advanced imaging, histopathology, molecular testing, and appropriate surgical and pharmacological interventions is critical for optimal outcomes in such rare presentations.