Zhou Jun, Xu Jingjing, Jiang Guozhong, Ma Yihui, Qi Jingwen, Li Wencai, Zhang Dandan
Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.
Oncol Lett. 2017 Feb;13(2):887-892. doi: 10.3892/ol.2016.5486. Epub 2016 Dec 12.
Gastric plexiform fibromyxoma (PF) is a rare mesenchymal tumor with a histologically distinctive multinodular pattern, dissimilar to conventional gastrointestinal stromal tumor (GIST). The current study presents one case of gastric PF, and one case of GIST with a platelet-derived growth factor receptor α () mutation mimicking PF, and discusses their differential diagnoses. The two patients were a 51-year-old male with PF and a 47-year-old female with GIST, each of whom presented with an occupying lesion in the gastric antrum. Histologically, the two cases shared a rare and approximately unanimous morphological pattern of a prominent multinodular and plexiform figuration in the gastric wall, including mucoid matrix, short spindle cells and small caliber vascular elements, and areas of stromal tumor cells exhibited an epithelioid appearance. Immunohistochemistry revealed that the PF tumor cells were positive for smooth muscle actin (SMA), but negative for mast/stem cell growth factor receptor (KIT), GIST-1 (DOG1), cluster of differentiation (CD) 34, S-100, desmin and cytokeratin AE1/AE3. The case of GIST expressed KIT and DOG1, but was negative for SMA, CD34, S-100, desmin and AE1/AE3. In addition, the GIST case, which was observed to harbor a D842V mutation in exon 18 of , was demonstrated to be genetically distinct from PF. The cases presented in the current study were uncommon in that GIST exhibited a plexiform appearance that mimicked the histology of the rare PF tumor; therefore, GIST must be considered and discounted first when determining a differential diagnosis for a gastrointestinal mesenchymal neoplasm.
胃丛状纤维黏液瘤（PF）是一种罕见的间叶性肿瘤，具有组织学上独特的多结节模式，与传统的胃肠道间质瘤（GIST）不同。本研究报告了1例胃PF以及1例具有血小板衍生生长因子受体α（）突变且形态类似PF的GIST病例，并讨论了它们的鉴别诊断。这两名患者分别是1名患有PF的51岁男性和1名患有GIST的47岁女性，两人均表现为胃窦部占位性病变。组织学上，这两例病例在胃壁中均呈现出一种罕见且大致一致的形态模式，即显著的多结节和丛状形态，包括黏液样基质、短梭形细胞和小口径血管成分，且部分间质肿瘤细胞呈上皮样外观。免疫组织化学显示，PF肿瘤细胞平滑肌肌动蛋白（SMA）呈阳性，但肥大/干细胞生长因子受体（KIT）、GIST-1（DOG1）、分化簇（CD）34、S-100、结蛋白和细胞角蛋白AE1/AE3呈阴性。GIST病例表达KIT和DOG1，但SMA、CD34、S-100、结蛋白和AE1/AE3呈阴性。此外，该GIST病例在的第18外显子中检测到D842V突变，显示出与PF在基因上不同。本研究中呈现的病例并不常见，因为GIST呈现出一种丛状外观，类似于罕见的PF肿瘤的组织学表现；因此，在对胃肠道间叶性肿瘤进行鉴别诊断时，必须首先考虑并排除GIST。
