胰腺实性假乳头状瘤临床病理特征及免疫组化表型观察

Solid-pseudopapillary tumor of pancreas: a clinicopathological and immunohistochemical study

目的探讨胰腺实性假乳头状瘤(SPTP)的临床病理特征及免疫组化表型.方法对12例SPTP进行临床病理、免疫组化观察并随访2～44个月.结果12例SPTP占同期胰腺肿瘤4.7%;男女之比为1:11;平均年龄29岁;仅6例有临床症状;其中6例大体呈囊实性,6例呈实性;7例有肉眼可见的完整包膜.镜下11例肿瘤见纤维性包膜;肿瘤由形态相对一致的中等大小细胞构成;部分细胞可见核沟;肿瘤细胞排列成实性巢片状、假乳头状,伴发囊性变,并可见灶性及成片的出血坏死,另见多种其他结构,包括嗜酸性小球、瘤细胞黄瘤样变、间质黏液样变、伴有异物巨细胞反应的胆固醇性针样结晶,部分有浸润周围胰腺的现象.瘤细胞vimentin、AAT弥漫(+),部分病例Syn、CD56、CD10、AE1/AE3、PR局部(+),CgA均(-);嗜酸性小球PAS(+),且可抗淀粉酶消化;12例术后随访2～44个月,所有患者均术后无瘤生存,未发现复发及转移.结论胰腺实性假乳头状瘤多发于年轻女性,具有多种组织学结构、细胞形态及多向分化的免疫组化表型.该肿瘤发展缓慢,生存时间长,但少数可复发、转移,为低度恶性肿瘤.

Objective To study the clinicopathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas （SPTP）. Methods Clinicopathological observation and immunohistochemical staining （En Vision two-step method） were used to analyse 12 cases of SPTP and the patients were then followed up for 2 to 44 months. Results 12 SPTP patients accounted for 4.7% of the 256 pancreatic tumors seen from 1999 to 2003. Ratio of female to male was 11 ： 1 ; average age was 29.0 years. Only 6 patients had symptoms. Grossly, 6 cases were solid-cystic, and 6 cases were solid. 7 cases appeared encapsulated. Histopathologically, 11 cases appeared to exhibit a fibrous capsule surrounding the tumors. Tumor cells were uniform and medium-sized. Some tumor cells had typical nuclear grooves. The cells arranged in sheets and nests and pseudopapillary patterns. In cystic areas, hemorrhage and necrosis were often seen. Other special forms were seen, including eosinophilic globules, some tumor cells exhibiting prominent cytoplastic vacuolization like xanthoma cell, myxoid change in the stroma,and clolesterol clefts with muhinuclear giant cell reaction. Immunohistochemical studies demonstrated that all the tumor cells reacted positively with vimentin and αAT. Staining for CD56, CD10, Syn, AE1/AE3 and PR were focal or faint. But CgA was not expressed. Eosinophilic globules were positive with PAS stain, resistant to diastase. 12 cases were followed-up for 2 to 44 months after operation, and all patients were alive without recurrence or metastasis. Conclusions SPTP is a tumor predominantly occurring in young women, and characteristically has various histological patterns and multiple morphogenetic cells with different immunophenotype in different regions. SPTP grows slowly and patients with SPTP have long-term survival. Though its recurrence and metastasis are rare, SPTP is regarded as a tumor with low malignant potential.