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In Situ Hybridization is a Valuable Diagnostic Tool in Cutaneous Deep Fungal Infections
Author(s) -
Abbott J.J.,
Hamacher K.L.,
Bridges A.G.,
Ahmed I.
Publication year - 2005
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/j.0303-6987.2005.0320a.x
Subject(s) - dimorphic fungus , blastomycosis , pathology , histoplasmosis , in situ hybridization , biology , cryptococcosis , dermatology , paracoccidioidomycosis , mycosis , medicine , immunology , biochemistry , gene expression , genetics , gene , yeast
Dimorphic fungal infections (histoplasmosis, blastomycosis, coccidiomycosis, and cryptococcosis) can occur in immunocompromised and healthy individuals. Cutaneous involvement is often secondary and may be the presenting sign of systemic disease. These ominous infections are frequently clinically indistinct and their prognosis is influenced by their timely diagnosis and treatment. Morphological differentiation between these organisms is not definitive and tissue cultures represent the diagnostic gold standard in current day practice. However, not uncommonly tissue cultures are not obtained and merely represent an afterthought in seemingly unsuspecting cases. Furthermore, when performed, they may take several days to weeks for completion. In situ hybridization (ISH) utilizing oligonucleotide probes directed against fungal ribosomal RNA represents a rapid and accurate assay for the diagnosis of dimorphic fungi in paraffin‐embedded tissue sections. We present 7 patients in whom ISH both prospecitively and retrospectively confirmed the presence of a cutaneous infection (2 histoplasmosis, 2 blastomycosis, 1 coccidiomycosis, 2 cryptococcosis). In all of the skin sections analyzed, dimorphic fungi were morphologically apparent but not diagnostically discernable. In summary, ISH represents a valuable tool in the prompt diagnosis of cutaneous deep fungal infections.