An 82-year-old woman presented to our hospital with a deep skin ulcer in her right lower limb. Although the skin biopsy showed necrosis and neutrophil infiltration, we could not initially detect any pathogen. Chest radiography showed multiple nodules despite the lack of respiratory symptoms or fever, and the serum latex agglutination test for cryptococcus showed an elevated titer (1:512). Considering these findings, we performed additional stains of periodic acid-Schiff reaction and Grocott to the skin-biopsy specimen and detected multiple yeast-like fungi. The cultures of the skin and lung-biopsy specimens revealed Cryptococcus neoformans. In this case, it is suggested that a large deep skin ulcer can be an initial manifestation of systemic cryptococcosis, as, in some cases, pulmonary cryptococcosis may be asymptomatic. Second, cutaneous cryptococcosis of an unexposed area such as the thigh can contribute to the diagnosis of systemic cryptococcal infection because it is attributable to bloodstream dissemination from other organs.
Keywords: Cryptococcus neoformans; Glucocorticoids; Skin ulcer; Systemic cryptococcosis.