Iwasaki H, Ohjimi Y, Ishiguro M, Isayama T, Kaneko Y, Yoh S, Emoto G, Kikuchi M
Departments of Pathology, Fukuoka University School of Medicine, Japan.
Cancer Genet Cytogenet. 1996 Oct 1;91(1):46-52. doi: 10.1016/s0165-4608(95)00315-0.
Epithelioid sarcoma is a peculiar soft-tissue neoplasm of uncertain origin, which is characterized by an epithelioid morphology of tumor cells coexpressing epithelial (keratin) and nonepithelial (vimentin) antigens. We herein report a new cytogenetic abnormality with der(22)t(18;22)(q11;p11.2) in a case of epithelioid sarcoma that occurred in the elbow of a 75-year-old man. Histologically, the tumor demonstrated a multinodular proliferation of epithelioid cells, with positive immunostaining for keratin, epithelial membrane antigen (EMA), and vimentin. Cultured tumor cells obtained from fresh surgical materials were frozen in plastic ampules and stocked in a liquid nitrogen freezer. Six years after surgery, the cells were recovered from the freezer and utilized for both morphologic and cytogenetic analyses. These cultured cells both before and after the freezing exhibited essentially the same epithelioid morphology and immunophenotypes as those of the original tumor. A chromosome analysis, together with fluorescence in situ hybridization (FISH), demonstrated a 61-67 modal population, and a characteristic clonal abnormality with der(22)t(18;22)(q11;p11.2). Other clonal abnormalities included numerical (-3, -4, +7, -13, -14, -16, -18, +20, -22) and structural (8p+, 9p+, 12p+, i(21q)) aberrations. Some variant clones also demonstrated i(18q). Since the breakpoint at 18q11 is similar to that reported in synovial sarcoma, this finding may support the presence of a histogenetic relationship between epithelioid sarcoma and synovial sarcoma. Our study thus indicates that the storage of frozen cells is useful for both morphologic and cytogenetic analyses of soft tissue tumors.
上皮样肉瘤是一种起源不明的特殊软组织肿瘤，其特征是肿瘤细胞具有上皮样形态，同时共表达上皮（角蛋白）和非上皮（波形蛋白）抗原。我们在此报告一例发生于一名75岁男性肘部的上皮样肉瘤，其存在一种新的细胞遗传学异常，即der(22)t(18;22)(q11;p11.2)。组织学上，肿瘤表现为上皮样细胞的多结节性增殖，角蛋白、上皮膜抗原（EMA）和波形蛋白免疫染色呈阳性。从新鲜手术材料中获取的培养肿瘤细胞被冻存于塑料安瓿中，并保存在液氮冷冻箱中。手术后六年，细胞从冷冻箱中复苏，用于形态学和细胞遗传学分析。这些冷冻前后的培养细胞与原始肿瘤细胞表现出基本相同的上皮样形态和免疫表型。染色体分析结合荧光原位杂交（FISH）显示，核型众数为61 - 67，存在特征性的克隆性异常der(22)t(18;22)(q11;p11.2)。其他克隆性异常包括数目异常（-3、-4、+7、-13、-14、-16、-18、+20、-22）和结构异常（8p+、9p+、12p+、i(21q)）。一些变异克隆还表现出i(18q)。由于18q11处的断点与滑膜肉瘤中报道的相似，这一发现可能支持上皮样肉瘤与滑膜肉瘤之间存在组织发生学关系。因此，我们的研究表明，冷冻细胞的保存对于软组织肿瘤的形态学和细胞遗传学分析是有用的。
