BACKGROUND: Microcystic adnexal carcinoma (MAC) is a subset of sweat gland carcinoma first described as a specific entity by D. J. Goldstein, R. J. Barr, and D. J. Santa Cruz (Cancer 1982;50:566-72). We report the first case of MAC occurring on the vulva and review the literature pertaining to this rare tumor. CASE: A 43-year-old multiparous black woman presented initially to Kings County Hospital Medical Center with a chief complaint of a vulvar lesion arising on the left labia majora which she had noted for 4 years prior to presentation. Aside from increasing paresthesia in the area, she denied any constitutional symptoms. Her past medical history was significant only for hyperthyroidism and mild hypertension and surgical history was noncontributory. Gynecologic history was unremarkable, with sporadic care over the last 20 years. Physical examination revealed a 1.5 x 2.0-cm raised, well-circumscribed, firm mobile lesion on the left labia majora. It was noted to be yellow in color with the surrounding tissue being unremarkable in character. The remainder of her gynecologic examination and lymph node survey was unremarkable. Preoperative chest X ray was negative as was the CAT scan of the abdomen and pelvis. All laboratory values were within normal limits. A Pap smear done preoperatively was significant for atypical squamous and glandular cells of undetermined significance. Subsequent colposcopic examination of the cervix was remarkable for cervicitis and was adequate, with the entire transformation zone visualized. Both endocervical curettage and endometrial biopsy were normal. Initially, an excisional biopsy was performed with final pathology demonstrating microcystic adnexal carcinoma with positive surgical margins. She subsequently underwent a left radical hemivulvectomy with bilateral inguinal groin lymph node dissection. At the time of surgery, the left labia majora was noted to be well healed, with a residual surgical scar easily discernible. No areas of discoloration were noted and digital palpation of the area was unremarkable. Microscopic residual tumor was noted; however, all surgical margins and lymph nodes were negative for tumor. Her postoperative course was unremarkable. The patient has continued to do well since the time of her surgery and is being followed conservatively. CONCLUSION: Radical vulvectomy should be performed when MAC occurs in the vulva to secure negative margins of resection. Groin dissection should be reserved for cases in which the inguinal lymph nodes are clinically suspicious or in cases of tumor recurrence.
