ThinPrep liquid‐based cytologic diagnosis of hepatic entomophthoromycosis (basidiobolomycosis) with Splendore‐Hoeppli phenomenon

Abstract Zygomycotic fungal infections are increasingly recognized in immunocompetent and immunocompromised patients in nonendemic countries because of the increased global travels. One of the emerging fungal infections is Entomophthorales which cause deep visceral infections that clinically and radiologically mimic malignancies because they form invasive obstructing masses. A quick diagnosis is life‐saving. The current standard diagnosis relies on histopathologic examination and microbiology culture which are time consuming. Cytologic examination is a rapid reliable alternative diagnostic tool. There are a few reports of a primary cytologic diagnosis of zygomycotic and Aspergillus fungi of the lungs based on conventional smear and SurePath™ liquid‐based cytology. We report a case of an immunocompetent adult female who presented with a liver mass that was clinically and radiologically diagnosed as cholangiocarcinoma. Fine‐needle aspiration cytology revealed the cytopathologic features of basidiobolomycosis in ThinPrep® cytology. The ThinPrep® slide revealed broad thin‐walled widely branching septate hyphae with sporangiophores and zygospores. The background revealed bile‐stained granular necrotic debris intermixed with inflammatory cells, degenerate hepatocytes, and highly eosinophilic glassy crystal‐like structures suggestive of Splendore‐Hoeppli phenomenon. The cytologic diagnosis was hepatic entomophthoromycosis (basidiobolomycosis) with Splendore‐Hoeppli phenomenon. This was confirmed by subsequent tissue biopsy and microbiology culture. The detailed cytomorphologic features in the ThinPrep® slide allowed the correct cytologic diagnosis and proper classification of the filamentous fungi. The ThinPrep® cytology was superior to tissue biopsy because it was faster and revealed the characteristic pauciseptate fungal hyphae, sporangiophores and zygospores. Liquid‐based cytology is a valuable quick tool in the diagnosis of fungal mass‐forming lesions.