Contributed by Jennifer Picarsic, MD and Mamatha Chivukula, MD, FASC, FCAP
A 35-year-old G2P2, presented at nine-months post-partum to her gynecologist for increased left labial swelling over a 2-month period. Pertinent medical history included two spontaneous vaginal deliveries, menorrhagia with known uterine fibroids, and no abnormal Pap smears. Physical examination at that time demonstrated a painless 7 cm mass in the area of the left Bartholin gland. An incision and drainage performed by the primary gynecologist revealed expression of gelatinous material. The mass recurred over the next two months, and the patient transferred her care to our institution. A radical vulvectomy with additional deep margins was performed at our institution.
Gross examination revealed a well-circumscribed mass, partially encapsulated with a tan-yellow mucinous appearance, without evidence of hemorrhage or necrosis. The original aggregate measurement of the mass on incisional biopsy was 7.0 cm. The follow-up excisional mass measurement at our institution was 2.5 x 1.5 x 1.5 cm (Figure 1).
Microscopic evaluation showed interlacing fascicles of spindle cells intermixed with acellular mucinous (myxoid) areas (Figure 2). In some areas the tumor was highly cellular with epithelioid areas composed of round-to-oval cells with bizarre nuclear features but displayed a low mitotic count (< 2 per 10 high power fields) (Figure 3). There were occasional medium-sized hyalinized vessels and an inflammatory infiltrate with eosinophils and lymphocytes. Rare giant cells with foreign body reaction were seen (Figure 4). The immunohistochemical staining profile showed positivity for desmin (Figure 5), vimentin (Figure 6), estrogen receptor (Figure 7) and progesterone receptor (Figure 8); but was negative for smooth-muscle actin, muscle specific actin (HHF35), caldesmon, CAM 5.2, AE1/AE3, CD68, CD34, HMB-45, S100.