Dermatofibrosarcoma Protuberans Presenting in a Patient With Neurofibromatosis Type 1: Potential Implications on Treatment.

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma. Neurofibromatosis type 1 (NF1) is a neurocutaneous syndrome that affects multiple organ systems. We present the case of a 47-year-old African American male with a two-year history of a slowly enlarging right lower back lesion. Upon workup, the 3 × 2 cm mass was biopsied confirming a diagnosis of DFSP. This was identified in concert with axillary freckling, café-au-lait spots, and pedunculated plaques evaluated with biopsy. The findings were consistent with neurofibromas, leading to a new diagnosis of NF1. The patient was definitively treated with wide local excision of the DFSP lesion without tumor recurrence over six years. DFSP has a favorable prognosis when treated with wide local excision and negative surgical margins. However, lesions may recur with inadequate margins. Although deferred in our patient, treatment with imatinib mesylate, a tyrosine kinase inhibitor, may be employed in the setting of advanced disease, metastasis, positive surgical margins, or irresectable locations. Imatinib has also been used to treat NF1. Hence, we posit that the concomitant presentation of these two disease entities in our patient highlights a potentially unique treatment with imatinib mesylate. To our knowledge, this is the second reported case of both entities in the same patient.