Malignant Perivascular Epithelioid Cell Tumor of the Uterus with Lung Metastasis

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Perivascular epithelioid cell tumor (PEComa) is an extremely rare mesenchymal tumor, which can arise in a wide array of ana­ tomic locations, and is characterized by its myelomelanocytic phenotype and unpredictable natural history. Specifically, PEC­ omas, which occur in non­classic anatomic distributions, are known as PEComa–not otherwise specified (PEComa‐NOS). 1 To the best of our knowledge, a total of 234 cases of PEComas­ NOS have been reported in English published reports. Of those, 47 were uterine PEComas cases, which included 31 tumors of benign behavior and 16 tumors of locally aggressive behavior with distant metastasis to liver, lungs, intestines, bone, and lymph nodes. Here, we report a very rare malignant uterine PEComa with lung metastasis in a 49­year­old unmarried woman, de­ spite adjuvant chemotherapy after initial surgery. A 49­year­old unmarried woman visited a gynecologist com­ plaining of her abnormal uterine bleeding, which had lasted for 1 week. Her past medical history was unremarkable. Upon vag­ inal examination, the uterus was slightly enlarged and there was a moderate tenderness in the lower abdomen. Ultrasonography showed a 9.5 cm×8.0 cm×7.5 cm­sized tumor with high vas­ cularity, arising from the anterior wall of the uterine corpus. Vi­ tal signs were within normal range. The initial laboratory find­ ings were normal, except for a low hematocrit level of 28%. The chest X­ray showed no active lung lesions (Fig. 1A). Under the diagnosis of uterine leiomyoma, she was taken to the operative room the following day. During the explorative laparotomy, a large, fungating, vascular mass arising from the anterior wall of the uterine corpus was noted. Myomectomy was performed be­ cause of her desire to preserve the uterus. The specimen was sent to a pathologist for frozen section. The pathologist conformed that the mass was highly suspicious for malignancy with high mitotic figures and marked nuclear anaplasia. Consequently, a total abdominal hysterectomy and bilateral salpingo­oophorec­ tomy was perform ed. On gross examination, the tumor was an ovoid firm myomatous nodule (8.5×8.0×6.5 cm). On section, the cut surface of the mass showed yellow white fish­fleshy ap­ pearance with multifocal necrosis (Fig. 2A). Microscopic review revealed that the tumor cells were predominantly composed of epithelioid cells with eosinophilic cytoplasm. Also, …