Case Report DOI: 10.18231/2348-7682.2017.0015 Panacea Journal of Medical Sciences, January-April,2017;7(1): 53-55 53 Malignant perivascular epithelioid cell neoplasm of uterus: A great mimic of fibroid Vaishali Walke 1,* , S. Kawathalkar 2 , R. Rane 3 , M. Goel 4 , WK Raut 5 1 Assistant Professor, 2 Associate Professor, 3,4 Resident, 5 Professor & HOD, Dept. of Pathology, Govt. Medical College, Nagpur, Maharashtra *Corresponding Author: Email: drvaishaliw@yahoo.com Abstract Perivascular epithelioid cell (PEC) neoplasms are an unusual group of mesenchymal tumors which arise from the perivascular epithelioid Cell that characteristically expresses melanocytic and muscle markers. These neoplasms show a wide range of morphologic spectrum and have been described in multiple anatomical locations which includes uterus. We report a 46- year-old patient diagnosed as uterine fibroid on ultrasonography in whom the hysterectomy specimen unveiled characteristic features of intramural PEComa consisting of small nests and sheets of clear epithelioid cells particularly present around the blood vessels in a background of loose oedematous stroma along with the foci of mature adipose tissue which exhibits myometrial infiltration. The correct diagnosis is crucial as there is an emerging role of mTOR inhibitors which can provide a ray of hope to the patients of PEComa. Keywords: PEComa of uterus, Angiomyolipoma, Uterine epithelioid cell tumour. Introduction Perivascular epithelioid cell tumor (PEComa) is a collection of rare neoplasms defined by the World Health Organization as mesenchymal tumors which on histology and immune staining reveal distinctive melanocytic and smooth muscle differentiation. Hence thought to be derived from perivascular epithelioid cell. (1) The PEComa family of tumorincludes AML(angiomyolipoma), CCST(clear cell sugar tumor), LAM (lymphangiomyomatosis), and less well-defined PEComa of other anatomic locations called perivascular epithelioid cell tumor not otherwise specified (PEComa-NOS). (2) Most of the published literature on PEComa-NOS is as case reports and series, which emphasize on its presentation and morphology. Here we report a case of uterine PEComa misdiagnosed as fibroid clinico-radiologically. We will discuss this case to stratify it along the risk stratification criteria which may help to improve upon its management. Case History A 46-year-old married female visited hospital complaining of abnormal uterine bleeding of 5 months duration. Her past medical history was unremarkable. There was no history of contraceptives use or hormonal therapy. On clinical examination, the uterus was enlarged approx. 24 wks with moderate tenderness in lower abdomen. Ultrasonography showed 14 cm ×12 cm × 8 cm sized, hypoechoic lesion in the uterus with mild vascularity and necrotic changes suggestive of degenerative fibroid. Her hemoglobin level was 8.0gm%, rest all laboratory findings were within normal limits. She underwent total abdominal hysterectomy and bilateral salpingo-oopherectomy. On gross the uterus with cervix was of size 15 cm × 12 cm × 7cm. Endometrial cavity was distorted by the tumor of size 12 cm ×10 cm ×7 cm. It was well circumscribed; the cut surface was solid, greyish white and fleshy. There was also a cyst in the left ovary of size 5 cm × 4 cm × 1.5cm. On cut section, cyst contained sebaceous material and hair. On histology, the tumor revealed two cell types. There was admixture of epithelioid to spindled shaped tumor cells (Fig. 1). Fig. 1: Tumor composed of epithelioid, cells in diffuse sheets, groups of fat cells and thick walled blood vessels (10X) The individual cells had eosinophilic to clear cytoplasm with central to eccentric, round to oval nuclei with fine chromatin and inconspicuous nucleoli (Fig. 1a).