Dermatofibrosarcoma Protuberans - A Diagnostic Dilemma on Cytology

Dermatofibrosarcoma protuberans (DFSP) is a subcutaneous soft tissue sarcoma with intermediate malignant potential and a characteristically indolent growth pattern. It often presents initially as a plaque-like lesion before progressing to a nodular mass. While histopathological examination remains the definitive diagnostic modality, fine-needle aspiration cytology (FNAC) is a rapid, minimally invasive technique that can provide an early diagnostic indication, particularly in superficial or recurrent lesions. We report the case of a 25-year-old female who presented with a slowly enlarging lump in the right flank. FNAC revealed a highly cellular lesion composed of spindle cells arranged in a storiform pattern, exhibiting mild pleomorphism, inconspicuous nucleoli, scant cytoplasm, and a collagenous stromal background, raising suspicion of an intermediate-grade spindle cell neoplasm, favouring DFSP. Histopathological evaluation demonstrated a characteristic storiform architecture of uniform spindle cells with diffuse CD34 immunopositivity. Although FNAC is valuable in the initial assessment of such lesions, cytological differentiation from other soft tissue tumours remain challenging due to significant morphological overlap with other spindle cell neoplasms of the skin and subcutis. This case highlights the diagnostic limitations of cytology in DFSP and underscores the importance of histopathological correlation.