Orbital dermatofibrosarcoma protuberans with intracranial extension preceded by recurrent leiomyoma of the orbit: a case report

INTRODUCTION: Dermatofibrosarcoma protuberans is a rare, locally aggressive cutaneous tumor of intermediate to low-grade malignancy. COL1A1-PDGFβ translocation is specific to dermatofibrosarcoma protuberans, where the abnormally fused COL1A1-PDGFβ gene directs formation of an abnormal combined (fusion) protein that researchers believe to ultimately function like the platelet-derived growth factor-beta protein. CASE PRESENTATION: In this report, we present a case of a 63-year-old Asian man with dermatofibrosarcoma protuberans of the right orbit with intracranial extension. He had a prior history of recurrent leiomyomas at the identical site. He underwent near-total en bloc resection of the tumor through a wide craniectomy with a 6cm rim of the frontal scalp, allowing the tumor to be resected en bloc, leaving negative margins. Microscopically, the tumor comprised spindle cells with mild nuclear atypia and a low mitotic index embedded in a spiraling pattern of decussating fascicles consistent with dermatofibrosarcoma protuberans. The lesion was positive for CD34 and BCL2. Following resection, the patient was started on imatinib mesylate therapy (800mg/day). CONCLUSIONS: We propose that platelet-derived growth factor, which has been implicated in the progression of leiomyomas by augmenting mitogenesis, may have acted in an autocrine manner to cause cell division, which may have led to the development of dermatofibrosarcoma protuberans in our patient. Further research is imperative to find certain molecular associations between the discussed soft tissue tumors. Also important is the effective utilization of platelet-derived growth factor receptor kinase inhibitors to prevent transformation to any platelet-derived growth factor–driven tumor, which in our patient was a dermatofibrosarcoma protuberans.