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

Abstract

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.

Dermatofibrosarcoma protuberans: Case series in a tropical setting and review of literature

“…The translocation represents the fusion of Collagen type1 Alpha1gene (COL1A1) on chromosome 17 and PDGFB gene on chromosome 22 that ultimately results in overproduction of PDGF, thus highlighting the rationale for the use of targeted therapy with Imatinib in the treatment of DSFP. 11 , 18 In cases without the COLIA1/PDGFB translocation, a different chromosomal translocation still involving PDFGB on chromosome 22 has been demonstrated. 7 In 10–20% of patients with this tumour, trauma at the site seems to be incriminated 15 , 16 as alluded to by some patients.…”