Cytopathological study of cutaneous and subcutaneous mycosis presenting as soft-tissue swellings: A 5-year retrospective study from a tertiary care center in South India

Abstract

Objectives: Cutaneous and subcutaneous mycosis can mimic skin and soft-tissue neoplasms clinically and pose diagnostic challenge to pathologists on cytology. Since there are a limited number of studies on this topic from South India and etiological agents vary with geographic region, in this paper, we present clinical and cytological features of the same the objective of this study is to review and evaluate clinical and cytological features of subcutaneous and cutaneous mycosis with histopathological correlation wherever available. Materials and Methods: This was an observational and retrospective study of 5-year duration. All cases diagnosed as mycosis on cytology were retrieved from pathology records. Cytology slides along with special stains for fungus were reviewed. Review of histopathology slides and culture correlation was done whenever available. Statistical analysis was done using frequencies and percentages. Results: There were 39 cases during the study period (male – 34 and female – 5). On aspiration, all cases yielded pus; microscopy revealed necrotic debris in 39 cases, inflammatory infiltrate in 39 cases, epithelioid granulomas with multinucleated giant cells in 25 cases, and negative staining hyphal forms in 37 cases. Special stains for fungus showed septate hyphal forms suggestive of Aspergillus species in 34 cases, and yeast and pseudo hyphal forms of candida species in one case. A broad category as fungal infection without subtyping was given in four cases. Culture did not yield growth but fungus was identified on KOH mounts. Histopathology showed fungus in 13 of 14 cases done. Conclusion: Subcutaneous mycosis should be suspected when aspiration yields pus and appropriate special stains must be done. Aspergillus species was the most common etiological agent in our study.