背景:血管周围上皮样细胞肿瘤(PEComas)很少见,间充质肿瘤由表现肌源性和黑素细胞分化的上皮样细胞组成。子宫是罕见的受累部位。最常见的组织病理学模拟物包括平滑肌肉瘤,子宫内膜间质肉瘤,未分化子宫肉瘤,还有恶性黑色素瘤.准确的组织病理学诊断至关重要,由于预后和治疗的影响。
方法:一名65岁绝经后妇女出现绝经后出血,腹痛,和沉重的过去四个月。腹部超声显示大的子宫肿块取代了子宫内膜腔。她接受了全腹部子宫切除术和双侧附件卵巢切除术。
结果:微观,肿瘤细胞排列成片状,交错成束,散布着细小的毛细血管网络,被看见了。单个肿瘤细胞为上皮样至纺锤形,中度多态性,圆形原子核,囊泡染色质,突出的大核,和中等细胞质。有丝分裂为2-3/50HPFs。关于免疫组织化学,肿瘤细胞HMB-45,Melan-A,和平滑肌肌动蛋白,对h-caldesmon呈阴性,TFE3、S-100、CD10和泛细胞角蛋白。根据组织病理学和免疫组织化学特征,最终诊断为恶性子宫PEComa。
结论:本索引报告描述了恶性子宫PEComa的特征性组织病理学和免疫组织化学特征,并强调了其与其他常见组织病理学模拟物的显著特征。
BACKGROUND: Perivascular epithelioid cell tumors (PEComas) are rare, mesenchymal neoplasms composed of epithelioid cells exhibiting myogenic and melanocytic differentiation. The uterus is an infrequent site of involvement. The most common histopathologic mimics include leiomyosarcoma, endometrial stromal sarcoma, undifferentiated uterine sarcoma, and malignant melanoma. Rendering an accurate histopathologic diagnosis is essential, owing to the prognostic and therapeutic implications.
METHODS: A 65-years-old post-menopausal woman presented with post-menopausal bleeding, abdominal pain, and heaviness for the last four months. Ultrasound abdomen revealed a large uterine mass replacing the endometrial cavity. She underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy.
RESULTS: Microscopically, a circumscribed tumor with tumor cells arranged in sheets and interlacing fascicles, with interspersed fine capillary network, was seen. The individual tumor cells were epithelioid to spindle with moderate pleomorphism, round nuclei, vesicular chromatin, prominent macronucleoli, and moderate cytoplasm. Mitosis was 2-3/50 HPFs. On immunohistochemistry, tumor cells were positive for HMB-45, Melan-A, and smooth muscle actin and were negative for h-caldesmon, TFE3, S-100, CD10, and pan-cytokeratin. Based on the histopathologic and immunohistochemical features, a final diagnosis of malignant uterine PEComa was rendered.
CONCLUSIONS: This index report describes the characteristic histopathologic and immunohistochemical features of malignant uterine PEComa and highlights the salient features that distinguish it from other commonly encountered histopathologic mimics.