"Malignant" Uterine Perivascular Epithelioid Cell Tumor, Pelvic Lymph Node Lymphangioleiomyomatosis, and Gynecological Pecomatosis in a Patient With Tuberous Sclerosis

Abstract

We report a case of uterine perivascular epithelioid cell tumor (PEComa) with malignant histological features in a 59-year-old woman with tuberous sclerosis (TBS). The patient also had extrapulmonary lymphangioleiomyomatosis involving pelvic lymph nodes, myometrium, cervix, and ovary ("pecomatosis"). The uterine tumor measured 2.6 cm and had marked nuclear pleomorphism, necrosis, and 2 mitoses per 50 high-powered field, with an occasional atypical mitosis and infiltrative borders. The nonneoplastic myometrium, the cervical wall, and the hilum of the ovary had multiple clusters of bland-looking epithelioid clear cells that ranged from 1 to 5 mm (pecomatosis). The uterine tumor cells were positive for HMB-45 (90%), Melan-A (70%), smooth muscle actin (50%), and estrogen receptor (30%). Of the 16 pelvic lymph nodes excised, 3 were involved with lymphangioleiomyomatosis that was positive for HMB-45 and estrogen receptor. This is only the second reported PEComa associated with pecomatosis and the fourth PEComa described in a patient with TBS. The clinical significance of pecomatosis is still uncertain but seems to be seen only in patients with TBS.