Nishimori Isao, Kohsaki Takuhiro, Tochika Naoshige, Takeuchi Tamotsu, Minakuchi Tomoko, Okabayashi Takehiro, Kobayashi Michiya, Hanazaki Kazuhiro, Onishi Saburo
Department of Gastroenterology and Hepatology, Kochi Medical School, Nankoku, Kochi, Japan.
Pathol Int. 2006 Nov;56(11):707-11. doi: 10.1111/j.1440-1827.2006.02034.x.
Solid-pseudopapillary tumor (SPT) is an unusual pancreatic neoplasm that is characterized by a mixture of solid and cystic components and a fibrous capsule. Recently, the tumorigenesis of SPT has been reported to be associated with gene mutations of beta-catenin, which is a molecule participating in the Wnt signaling pathway. Reported herein is the case of a 53-year-old woman with SPT. The tumor, approximately 3 cm in diameter in the pancreas body, had a clear margin and central calcification but had neither a cystic component nor fibrous capsule. Several lines of pathological findings in the surgically resected specimen indicated SPT: (i) pseudopapillary proliferation of eosinophilic polygonal cells with oval nuclei; (ii) positive expression of several marker molecules indicating differentiation into acinar and endocrine cells; and (iii) zymogen granule-like structures in the cytoplasm on electron microscopy. Further, the tumor cells had intense nuclear accumulation of beta-catenin and an activating mutation, (34)Gly(GGA) to Arg(AGA), in exon 3 of the beta-catenin gene, as previously reported in most SPT. These findings suggest that association of the beta-catenin phenotype with development of the rare phenotype of SPT, a non-cystic and unencapsulated tumor, is unlikely.
实性假乳头状肿瘤（SPT）是一种不常见的胰腺肿瘤，其特征为实性和囊性成分混合以及有纤维性包膜。最近，据报道SPT的肿瘤发生与β-连环蛋白的基因突变有关，β-连环蛋白是一种参与Wnt信号通路的分子。本文报道了一例53岁患有SPT的女性病例。该肿瘤位于胰体部，直径约3 cm，边界清晰，有中央钙化，但既无囊性成分也无纤维性包膜。手术切除标本的多项病理结果提示为SPT：（i）嗜酸性多边形细胞呈假乳头状增生，细胞核呈椭圆形；（ii）多种标记分子呈阳性表达，表明向腺泡和内分泌细胞分化；（iii）电镜下细胞质中有酶原颗粒样结构。此外，肿瘤细胞中β-连环蛋白有强烈的核内积聚，且β-连环蛋白基因第3外显子有激活突变，即由（34）甘氨酸（GGA）突变为精氨酸（AGA），这与之前大多数SPT报道的情况一致。这些发现表明，β-连环蛋白表型与SPT罕见表型（非囊性且无包膜肿瘤）的发生之间不太可能存在关联。
