具有实体结构的嗜酸细胞性乳头状肾细胞癌3例临床病理分析

Clinicopathologic features of oncocytic papillary renal cell carcinoma with solid architecture

目的探讨具有实体结构的嗜酸细胞性乳头状肾细胞癌(OPRCC)的临床病理特点、免疫表型及鉴别诊断。方法对3例具有实体结构的OPRCC进行临床、组织形态学和免疫组化分析,并复习文献。另外选取10例经典型乳头状肾细胞癌和10例嗜酸细胞瘤作为对照。结果 3例OPRCC均为老年女性,年龄78～79岁。临床上均因体检发现。巨检:瘤组织边界清楚,2例可见包膜,切面灰褐色或棕色。镜检:瘤组织主要呈弥漫实性生长,局部可见管状、裂隙样结构和发育不全的乳头状结构;瘤细胞体积较大,圆形或多边形,胞质丰富,强嗜酸性颗粒状,核圆形或不规则,核分裂象罕见或无。2例可见局灶性坏死,1例可见泡沫状巨噬细胞,2例可见砂砾体。免疫组化:瘤细胞均呈vimentin和AMACR弥漫强(+);表达CD10和CK18不同程度(+),CK7、RCC和E-cadherin各有1例(+);所有肿瘤CD117和EMA均(-)。结论具有实体结构的OPRCC是一种非常罕见的肾细胞癌,形态学上与嗜酸细胞瘤有重叠,免疫组化染色有助于诊断和鉴别诊断。

Objective To study the clinicopathological features,immunophenotype and differential diagnosis of oncocytic papillary renal cell carcinoma（OPRCC） with solid architecture.Methods Three cases of OPRCC with solid architecture were investigated by clinical findings,histopathology and immunohistochemistry,and the related literature was also reviewed.Additionlly,10 cases of papillary renal cell carcinoma（PRCC） and 10 cases of oncocytoma（RO） were selected as controls.Results All 3 patients were elderly female aged 78 and 79 years.The tumors were all detected incidentally during health examination.Grossly,the tumors presented as well-circumscribed masses,of which two cases were surrounded by a thin regular capsule.The cut surface of the tumors was grayish to brownish tan.Histologically,the tumors were predominantly composed of large,round to polygonal shaped cells with abundant oncocytic cytoplasm,arranged in solid growth pattern.Tubular,clefts structures and focal abortive papillary structures were also present.The nuclei were round or irregular.None or very few mitotic figures were observed.Focal necrosis presented in two cases.In addition,foamy macrophages and psammoma bodies were seen in one and two cases,respectively.Immunohistochemically,all cases displayed strong and diffuse reactivity for AMACR and vimentin,but varying reactivity for CD10 and CK18;CK7,RCC and E-cadherin were positive only in 1 case,respectively.But all tumors were negative for CD117 and EMA.The above immunohistochemical profile was similar to the common type of PRCC.Conclusion OPRCC with solid architecture is a very rare renal cell carcinoma,which possesses overlapping histological features with oncocytoma.Immunohistochemical staining is helpful for its diagnosis and differential diagnosis.