Left Acetabular Osteoarticular Cryptococcosis in an Immunosuppressed Renal Transplant Recipient: A Case Report and Literature Review

In individuals with weakened immune systems, opportunistic fungal infections remain a major clinical challenge, particularly among solid organ transplant recipients. A 60‑year‑old post‑renal transplant patient with diabetes and hypertension presented with fever and escalating pain in the left hip. Imaging revealed an osteolytic lesion of the left acetabulum, initially suggestive of osteomyelitis. Fine needle aspiration cytology demonstrated encapsulated yeast forms, and special stains confirmed Cryptococcus species. Culture and targeted next‑generation sequencing identified Cryptococcus neoformans. The patient was treated with liposomal amphotericin B and high‑dose fluconazole, with therapy modified due to amphotericin‑associated nephrotoxicity. Clinical improvement was achieved following a tailored antifungal regimen and close monitoring of renal function. This case highlights the diagnostic difficulties posed by cryptococcal osteomyelitis in transplant recipients, where musculoskeletal symptoms can mimic bacterial or neoplastic conditions. It emphasizes the role of advanced molecular diagnostics for species confirmation when conventional methods are inconclusive, and the importance of individualized antifungal therapy in patients with renal compromise. Our report contributes to the limited documentation of acetabular involvement and reinforces the need to consider fungal etiologies in immunosuppressed patients presenting with atypical bone lesions.