Subcutaneous Phaeohyphomycosis: A Clinical Mimic of Skin and Soft Tissue Neoplasms-A Descriptive Study from India.

BACKGROUND: Phaeohyphomycosis is a fungal infection caused by heterogenous group of fungi known as phaeoid or dematiaceous fungi. It manifests in four clinical forms-cutaneous, subcutaneous, systemic and cerebral phaeohyphomycosis. The subcutaneous form is the most common presentation. Clinically these subcutaneous swellings resemble benign skin and soft tissue neoplasms like lipoma, sebaceous cyst or neurofibroma. Histopathology serves as a very useful tool in diagnosing these cysts by identifying the fungal elements.

METHODS: A retrospective review of all cases diagnosed as phaeohyphomycosis in the department of Pathology at a tertiary care centre in South India over 9 years (January 2009-December 2017) was done. The clinical, histopathological findings of these cases were reviewed and analysed.

RESULTS: Sixty-six cases of subcutaneous phaeohyphomycosis were reported during the 9 year period. Sixty-two per cent of these patients were diagnosed as skin and soft tissue neoplasms. In 94% cases, the extremities were affected. Multiple cysts were seen in 11% of patients. Fine needle aspiration cytology was done in 29 cases with fungal hyphae identified in all cases on cytology.

CONCLUSION: Subcutaneous phaeohyphomycosis mimics benign skin and soft tissue neoplasms clinically. Histopathological examination along with cytology plays a major role in diagnosis of phaeohyphomycosis and thus helps in appropriate patient management.