Cerebral Abscess Masquerading as Tuberculoma in a Post-Renal Transplant Chronic Kidney Disease Patient: A Diagnostic and Therapeutic Challenge.

Solid organ transplant recipients are at increased risk of acquiring serious infections. We present a case of a 48-year-old male with a history of renal transplantation in 2012, chronic kidney disease (CKD) Stage 4, hypertension, uncontrolled diabetes mellitus, and prior tuberculous pleural effusion. Laboratory investigations revealed significant renal impairment, persistent hyponatremia, hypokalemia, and subtherapeutic tacrolimus levels (2.50 ng/mL), reflecting challenges of CKD and chronic immunosuppression with mycophenolate mofetil and tacrolimus. Given his immunocompromised state and TB history, initial suspicion centered on intracranial TB reactivation. Brain MRI with contrast revealed a rim-enhancing lesion in the right parieto-occipital region with central diffusion restriction, suggestive of a cerebral abscess. Magnetic resonance spectroscopy (MRS) demonstrated elevated lactate (1.33 ppm) and amino acid peaks, confirming the diagnosis and excluding tuberculoma or high-grade glioma. Treatment included intravenous ceftriaxone, dexamethasone, and a CKD-adjusted anti-TB regimen (rifampicin, isoniazid, ethambutol, pyrazinamide), alongside phenytoin and continued immunosuppressants. This case underscores the diagnostic complexity of distinguishing cerebral abscesses from tuberculomas in post-transplant patients, highlighting the pivotal role of multi-modal imaging (MRI, MRS) and tailored therapy to manage infection, immunosuppression, and comorbidities effectively.