Hav Monirath, Lem Dara, Chhut Serey Vattana, Kong Rithy, Pauwels Patrick, Cuvelier Claude, Piet Pattyn
Department of Pathology, Ghent University Hospital, Belgium.
Malays J Pathol. 2009 Dec;31(2):137-41.
Solid-pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm reported to have a favourable prognosis because of its slow-growing behaviour. Ignored and misdiagnosed in the past, SPN has recently been increasingly studied. Its clear cell variant creates challenges in distinction from other clear cell tumours in the pancreas. We report a 31-year-old Cambodian woman who presented with abdominal pain and a palpable epigastric mass. Exploratory laparotomy revealed a 5.2 cm well-demarcated tumour in the head of the pancreas, which was treated with Whipple procedure. Microscopically, the tumour showed an extensive solid growth pattern consisting of cells with abundant clear cytoplasm, and papillary areas containing cells with eosinophilic cytoplasm, indicating a clear-cell solid-papillary neoplasm. Perineural and duodenal wall invasion was present. The tumour cells were immunonegative for chromogranin-A and synaptophysin but positive for CD56, cyclin D1, CD10, vimentin, and progesterone receptor. They showed strong nuclear and cytoplasmic expression and reduced membranous expression of beta-catenin protein. In the pseudopapillary area, they showed nuclear E-cadherin localization and absence of membranous staining. The patient was well without local recurrence or metastasis at one year follow-up. Difficulties are recognized in differentiating clear-cell SPN from "sugar" tumours, metastatic renal cell carcinoma, clear-cell variant of pancreatic endocrine neoplasm and ductal adenocarcinoma. When facing such difficulties, nuclear and cytoplamic beta-catenin, nuclear E-cadherin expressions and absence of membranous E-cadherin staining are useful in differentiating clear-cell SPN from other clear cell tumours in the pancreas. Although a rare neoplasm, it is important to recognize this entity for appropriate management.
胰腺实性假乳头状肿瘤（SPN）是一种罕见肿瘤，因其生长缓慢，据报道预后良好。过去该肿瘤常被忽视和误诊，近年来对其研究日益增多。其透明细胞变体在与胰腺其他透明细胞瘤的鉴别诊断中存在挑战。我们报告一名31岁柬埔寨女性，她因腹痛和上腹部可触及肿块就诊。剖腹探查发现胰腺头部有一个5.2 cm界限清楚的肿瘤，行Whipple手术治疗。显微镜下，肿瘤呈广泛实性生长模式，由富含透明细胞质的细胞组成，以及含有嗜酸性细胞质细胞的乳头状区域，提示为透明细胞实性假乳头状肿瘤。存在神经周围和十二指肠壁侵犯。肿瘤细胞嗜铬粒蛋白A和突触素免疫阴性，但CD56、细胞周期蛋白D1、CD10、波形蛋白和孕激素受体阳性。它们显示β-连环蛋白蛋白强核和细胞质表达及膜表达减少。在假乳头状区域，它们显示核E-钙黏蛋白定位且无膜染色。患者在随访一年时情况良好，无局部复发或转移。在将透明细胞SPN与“糖”瘤、转移性肾细胞癌、胰腺内分泌肿瘤透明细胞变体和导管腺癌鉴别时存在困难。面对这些困难时，核和细胞质β-连环蛋白、核E-钙黏蛋白表达及无膜E-钙黏蛋白染色有助于将透明细胞SPN与胰腺其他透明细胞瘤鉴别。尽管是罕见肿瘤，但认识这一实体对于恰当处理很重要。
