Subcutaneous Phaeohyphomycosis Cyst Associated with Medicopsis romeroi in an Immunocompromised Host

An 88-year-old man, receiving prednisolone for sarcoidosis, presented with a discrete keratotic lesion on the dorsum of his right hand following the placement of an intravenous cannula a month prior to its appearance. Medicopsis romeroi was isolated from the tissue and identified by sequencing the internal transcribed spacer region ITS-1 and the D1-2 fragment of the 28S rDNA gene. Histopathological examination showed fungal hyphae in the internal inflammatory cells layer and within the histocyte-macrophage layer, highly suggestive of deep mycosis. The patient was successfully treated with surgical excision of the cyst. M. romeroi exhibited high MIC values for echinocandin drugs in vitro, but appeared susceptible to newer triazole agents, amphotericin B and terbinafine. This is the first report of a subcutaneous phaeohyphomycotic cyst occurring following the placement of an intravenous cannula. This report highlights the potential role of M. romeroi as an emerging cause of deep, non-mycetomatous infection in immunocompromised patients.