Sequestration of active Cryptococcus neoformans infection in the parathyroid gland despite prolonged therapy in a renal transplant recipient.

Disseminated cryptococcal infection occurs mainly in the immunocompromised host, particularly in those with impaired cellular immunity. The treatment outcome depends not only on the duration and choice of antifungal therapy, but also on the activity of the organism to persist in different parts of the body despite therapy. We present a case of persistence of cryptococcal infection in the parathyroid gland in a kidney transplant recipient. A 38-year-old male renal transplant recipient diagnosed to have disseminated cryptococcosis was treated with discontinuation of immunosuppression, amphotericin B, and flucytosine for 2 weeks, and fluconazole subsequently. Dialysis was initiated when graft function deteriorated after discontinuation of immunosuppression. The patient showed no clinical signs of active cryptococcal infection on fluconazole therapy. One year after the diagnosis of cryptococcosis, and still on fluconazole, he underwent parathyroidectomy, for severe secondary hyperparathyroidism. Surprisingly, active cryptococcal infection with necrotizing granulomatous inflammation was demonstrated in the parathyroid, despite being on therapy. This patient illustrates that persistence of fungal infection despite prolonged therapy can occur in unusual sites such as the parathyroid and may be a source for future recurrence and dissemination.