Systemic cryptococcosis with solitary cutaneous lesion in an immunocompetent patient

A 55-year-old white farmer from north-east Brazil presented with a 1-month history of headache and a solitary nodular lesion on his face. He was a smoker and had reported contact with pigeons. He did not complain of any other systemic symptom such as cough or pain. Physical examination of the skin lesion revealed a nodule measuring approximately 3 cm in diameter with central ulceration and overlying crust (Fig. 1). The lesion clinically resembled a keratoacanthoma. Routine admission blood investigations, including a full blood count, liver function tests, and renal electrolytes, were normal. Serology for human immunodeficiency virus (HIV) (enzyme-linked immunoabsorbent assay (ELISA) and Western blot) was negative. Intradermal cutaneous tests for Streptococcus, Staphylococcus, E. coli, candida, and trichophytin were negative, whilst tuberculin reaction showed a weakened reactor. Potassium hydroxide (KOH) examination and tissue culture of the skin lesion demonstrated Cryptococcus neoformans. Chest X-ray revealed hilar and perihilar tumor localized to the anterior mediastinum. Cytology of cerebrospinal fluid (CSF) from lumbar puncture revealed 90% monocytes and 10% polymorphs. Glucose (11 mg%) and protein (405 mg%) levels of the CSF were elevated, whilst flow cytometry of the CSF gave 125 cells/mm3. KOH examination and culture of the CSF were negative. Histologic examination of the cutaneous nodule demonstrated a dermal lymphohistiocytic infiltrate with a granulomatous reaction. On hematoxylin and eosin stained sections, microorganisms were seen, characterized by spores surrounded by a pale capsule. Alcian blue/periodic acid-Schiff (PAS) staining further highlighted fungal structures. The microscopic findings seen were characteristic of Cryptococcus neoformans (Figs 2 and 3). Cryptococcus neoformans was grown in tissue culture confirming the diagnosis of cutaneous cryptococcosis. After thoracotomy, biopsy of the chest tumor demonstrated a few fungus cells in a dense fibromatous tissue (Fig. 4) consistent with the diagnosis of a cryptococcoma. Surgical removal of this tumor was deemed inappropriate due to the proximity of the heart and major vessels. After 1 month of therapy with fluconazole intravenously (400 mg/day), we observed total resolution of the lesion on the face. Repeated lumbar puncture revealed normalization of the CSF protein, whilst skin biopsy from the previously affected site became negative on KOH examination and culture. We continued treating our patient with oral fluconazole for a period of 7 months. Despite obvious cutaneous improvement, the mediastinal mass on chest X-ray was unchanged. At a 3-year follow-up period, the patient had remained asymptomatic, with no evidence of cutaneous or visceral recurrence.