Diagnostic Challenges of Dermatofibrosarcoma Protuberans (DFSP), a Rare Spindle Cell Tumor of Breast.

Dermatofibrosarcoma protuberans (DFSP) is a low-grade, fibroblastic tumor that is rarely seen in the breast with only a few cases reported in the literature. DFSP poses a diagnostic challenge as there is significant cytomorphological overlap with other spindle cell lesions. We report a case of a 42-year-old female who presented with a nodule in the right breast. Histology revealed a hypercellular lesion composed of spindle cells infiltrating the fat. A diagnosis of spindle cell lipoma was made. However, two years later, the patient developed a recurrent mass in the right breast that was histologically consistent with DFSP with a predominant myxoid stroma obscuring the characteristic storiform architecture with a focal component of giant cell fibroblastoma. A careful histomorphological examination is warranted as DFSP tends to recur if not completely excised.