Dermatofibrosarcoma protuberans (DFSP) of the vulva is a rare, slow-growing, low-to-intermediate-grade malignant tumor of the dermis layer of the skin classified as a sarcoma that usually invades the subcutaneous tissue and muscles (1-3). Although the exact cause of the DFSP of the vulva is unknown, studies have implicated a chromosomal translocation (4-6). The incidence of DFSP was 4.1 per million per year during 2000-2010 (7) or approximately 0.1% of all cancers and less than 1% of all sarcomas (8, 9). The tumor is seldom found in the vulva, with less than 50 cases currently reported in the medical literature (8, 10). The DFSP rarely leads to metastasis (fewer than 5% of cases). Vulvar DFSP is typically observed in middle-aged and older women and is diagnosed by biopsy. In most patients, it can be diagnosed using magnetic resonance imaging (MRI). The DFSP of the vulva grows slowly and presents for years before being noticed. They are painless when they are small, while large tumors can cause pain and discomfort due to pressure on the adjoining tissues and structures. The standard treatment techniques for resectable DFSP are complete surgical excision with wide the local excisions of 2 or 3 cm tumor-free margins (9, 11-13). Unresectable DFSPs are treated with radiation therapy. The prognosis of the DFSP of the vulva is good and depends on the cancer stage, as well as the overall health of the individual. Here, we present the clinical symptoms, radiological features, pathological characteristics, treatment, and prognosis of two cases with vulvar DFSP.

 

Case Presentation

One of the patients was a 37-year old Iranian woman presented at the Gynecology Oncology Department of Shahid Beheshti Hospital affiliated to Isfahan University of Medical Sciences, Iran, with a non-tender nodular 3×2 cm² lesion of solid texture without ulceration and treatment history. The tumor was located in labia major (Figure 1), and lymphadenopathy was not noted. The patient stated that mass was present for at least 6 months and grew slowly. Preoperative pelvic MRI showed a small mass with heterogeneous enhancement in the right side of the vulva vagina. However, the cervix and uterus body were unremarkable and had subtle secretion in the canal cavity. In chest computerized tomography (CT) and abdominopelvic ultrasonography, no metastatic disease was revealed. All routine blood tests and Pap smears were normal. Surgery was performed with wide local excision to obtain a 2 cm margin from the tumor. The patient had an uneventful postoperative recovery and was discharged after 2 days. The excised lesion of 7×6×3 cm³ contained multiple nodular lesions, and the largest with the diameter of 2 cm was sent for histopathology showing DFSP. Histological examination demonstrated a storiform and honeycomb pattern, positively stained for CD 34 and vimentin indicating DFSP (Figure 2). After 11 months of follow-up, she was disease-free, and there is no evidence of recurrence.

The second case was a 35-year-old woman who presented to a gynecologic oncologist for a recurrent 2 cm mass lesion in labia major one year after the surgical resection of a nodular mass lesion. On clinical examination, a 3×3 cm, non-tender, pink, nodular lesion of solid texture was present on the right labium major without ulceration (Figure 1). Lymphadenopathy was not observed, and pathological examination reported DFSP. Ultrasonography revealed a heterogeneous mass of 35×9 mm² in labia major, which contained solid cyst with ill-defined area and infiltration in subcutaneous fat. All routine blood tests and Pap smears were normal. Chest and abdomen CT showed no evidence of metastasis. The lesion was removed with 2 cm clear margins using a wide local excision technique. The excision involved the superficial and deep facial layers of the vulva. The remaining defect measured 6×3×2 cm and involved the right labium major and right upper inner thigh. The defect site was then repaired without the need for graft, and she was discharged home after 2 days. Specimens were sent for pathological examination, and DFSP was reported with a negative margin. This patient was followed for 3, 6, and 9 months (Figure 3) and was disease-free after 9 months.

Figure 3. Postoperative photograph demonstrating healing at 9-month and 11-month follow-up