Subcutaneous cryptococcosis due to Cryptococcus diffluens in a patient with sporotrichoid lesions case report, features of the case isolate and in vitro antifungal susceptibilities

Abstract

Environmental fungi, in particular primary pathogens and Cryptococcus spp. can be responsible for skin lesions mimicking sporotrichosis. In this paper, we report a case of subcutaneous cryptococcosis in an apparently healthy, young male patient due to a non-C. neoformans Cryptococcus species, C. diffluens. The isolate showed in vitro phenotypic switching that may affect virulence and host inflammatory and immune responses, and in vitro resistance to amphotericin B and 5-flucytosin. This species shares several phenotypic traits with C. neoformans, and, therefore, decisive diagnosis should be based on biopsy and culturing results followed by molecular identification.

Fig. 1

(A–F) Clinical appearance of the lesions, (A, B) before treatment, (C, D) at 10 days after treatment and (D, E) after 25 days of therapy.

Fig. 2

Imprinted tissue biopsy preparation showing encapsulated yeast cells (Giemsa stain, 100×).

Fig. 3

Microscopical morphology of the isolate: encapsulated yeast cells (India ink, 100×).

Fig. 4

Sectored colony with mucoid (MC) and wrinkled (WR) colony parts after growth on SDA for 72 h.

Fig. 5

Indirect immunofluorescens with Mab 2H1 of wrinkled (WR) and mucoid (MC) cells respectively (upper panel: 100× and lower panel: 40×).