Multisystemic Malakoplakia Revealed by 18F-FDG PET/CT: A Case of Concomitant Bilateral Osteomyelitis and Genitourinary Involvement

We present the case of a 43-year-old man with a history of myasthenia gravis on immunosuppressive therapy, mycophenolate mofetil, and recent hospitalization for prostatic abscess and recurrent left orchiepididymitis. 18F-FDG PET/CT demonstrated increased uptake in multiple intramedullary bone regions in the lower limbs, in the left testicle, in the prostate and in several retroperitoneal lymph nodes, all presenting with calcifications on CT. Based on PET/CT, prostate biopsy and bone bacterial cultures, a diagnosis of prostatic malakoplakia with concomitant testicular and lymph nodes involvement was made, complicated by bilateral lower limb osteomyelitis. This case highlights the potential value of 18F-FDG PET/CT in characterizing the extent of involvement and guiding the diagnosis of this rare multisystemic entity.