Histoplasmosis and subcutaneous nodules in a kidney transplant recipient: erythema nodosum versus fungal panniculitis.

Erythema nodosum (EN)-like lesions are a rare occurrence after solid organ transplantation. Differential diagnosis includes infective panniculitis, which can be a feature of progressive disseminated histoplasmosis (PDH), an uncommon but severe form affecting primarily immunocompromised hosts. We report on a fatal case of PDH, which presented as fungal panniculitis masquerading as EN in a renal allograft recipient 25 years after transplantation. We discuss the clinical, histopathological, and microbiological characteristics of this rare complication, with focus on its distinction from EN. This case emphasizes the central role of biopsy in transplant recipients presenting with cutaneous lesions, and the importance of clinicopathologic correlation and complementary microbiological investigations.