Vulvar dermatofibrosarcoma protuberans masquerading as angiomyxoma: A case report and review of 85 cases.

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous mesenchymal locally aggressive sarcoma with high recurrence. We report a case of recurrent vulvar DFSP, and a literature review was performed with a PubMed search using the terms "Dermatofibrosarcoma protuberans" and "vulva." Total 85 cases with vulvar DFSP were analyzed for their clinicopathological features among fibrosarcomatous DFSP (FS-DFSP) and non-FS-DFSP. Listless asymptomatic growth had resulted in delay in presentation of 2.3 years. Tumor size was significantly more in FS-DFSP (P 0.005). Higher mitotic rate is found to have strong association with FS-DFSP (P 0.0001). FS-DFSP has more recurrences compared with non-FS-DFSP (P 0.0001). DFSP with FS transformation was more aggressive as there was significant difference in metastasis (P 0.073, OR 0.18) and mortality (P 0.210, OR 0.19). To investigate the risk of outcome, 59 cases were included following the exclusion of <6 months follow-up. Age (>50 years) was found to be a risk for metastasis and death from the disease. Tumor size (>5 cm) and mitosis (≥5/10-HPF among non-FS-DFSP) were found to be the risk for the LR. Different histological diagnosis was made initially in 32%, and local excision was performed without margins in 65% of vulvar DFSP because of initial incorrect diagnosis. Therefore, pre-treatment biopsy or re-biopsy should be performed with immunohistochemistry for definitive diagnosis to exclude histologic mimics. The optimal treatment is wide local excision with 3-cm margin or with margin assessment for both primary and recurrent DFSP. As most recurrences occur within the first three years of wide excision in DFSP, regular follow-up visits are advocated.