Lee So Jung, Hwang Chung Su, Kim Ahrong, Kim Kyungbin, Choi Kyung Un
Department of Pathology, Pusan National University Hospital, Busan 49241, Republic of Korea.
Department of Pathology, Pusan National University Yangsan Hospital, Yangsan, Gyeongsangnam 50612, Republic of Korea.
Oncol Lett. 2016 Aug;12(2):1287-1292. doi: 10.3892/ol.2016.4758. Epub 2016 Jun 22.
Leiomyomas and schwannomas of the gastrointestinal tract (GIT) are mainly comprised of spindle-shaped tumor cells and should always be differentiated from gastrointestinal stromal tumors (GISTs). Mast/stem cell growth factor receptor Kit (KIT) and discovered on GIST-1 (DOG1) are well-known diagnostic markers for the detection of a GIST by immunohistochemical staining. The aim of the present study was to assess the prevalence and significance of spindle cell tumors of the GIT with KIT- or DOG1-positive spindle-shaped cells, presumed to be interstitial cells of Cajal (ICCs), other than GISTs. A total of 71 leiomyomas and 35 schwannomas were examined and clinicopathological information was obtained. KIT and DOG1 immunostaining was performed to determine the proportions of positive cells. Mutation screening of KIT exons 9, 11, 13 and 17, and platelet-derived growth factor receptor α (PDGFRA) exons 12 and 18 was performed in cases with a relatively high proportion of either KIT- or DOG1-positive cells. The frequency of leiomyomas and schwannomas with KIT- and DOG1-positive ICCs was 35.2% (25/71 cases) and 5.7% (2/35 cases), respectively. Among the esophageal leiomyomas with KIT- and DOG-positive ICCs (14/25; 56.0%), 5 leiomyomas involved the muscularis mucosa and 9 leiomyomas involved the muscularis propria. All gastric leiomyomas with KIT- and DOG1-positive ICCs (11/25; 44%) involved the muscularis propria. All schwannomas with an increased proportion of KIT- or DOG1-positive ICCs were of gastric origin. No KIT or PDGFRA mutations were detected in 7 leiomyomas and 2 schwannomas. In conclusion, the majority of leiomyomas and the minority of schwannomas in the GIT had a significant portion of KIT- and DOG1-positive cells. All of the tumors were located in the upper GIT, and could be present in the muscularis propria or muscularis mucosa. The tumors represented a non-neoplastic proliferation of KIT- and DOG1-positive cells in the GIT. Careful evaluation of KIT- or DOG1-positive cells in spindle cell tumors of the GIT can assist in forming the correct diagnosis by differentiation from a GIST.
胃肠道（GIT）的平滑肌瘤和神经鞘瘤主要由梭形肿瘤细胞组成，应始终与胃肠道间质瘤（GIST）相鉴别。肥大/干细胞生长因子受体Kit（KIT）和GIST-1发现蛋白（DOG1）是通过免疫组织化学染色检测GIST的著名诊断标志物。本研究的目的是评估GIT中具有KIT或DOG-1阳性梭形细胞（推测为Cajal间质细胞（ICC））的梭形细胞肿瘤（而非GIST）的患病率及意义。共检查了71例平滑肌瘤和35例神经鞘瘤，并获取了临床病理信息。进行KIT和DOG1免疫染色以确定阳性细胞的比例。对KIT外显子9、11、13和17以及血小板衍生生长因子受体α（PDGFRA）外显子12和18进行突变筛查，针对KIT或DOG1阳性细胞比例相对较高的病例。KIT和DOG1阳性ICC的平滑肌瘤和神经鞘瘤的频率分别为35.2%（25/71例）和5.7%（2/35例）。在具有KIT和DOG阳性ICC的食管平滑肌瘤中（14/25；56.0%），5例平滑肌瘤累及黏膜肌层，9例平滑肌瘤累及固有肌层。所有具有KIT和DOG1阳性ICC的胃平滑肌瘤（11/25；44%）均累及固有肌层。所有KIT或DOG1阳性ICC比例增加的神经鞘瘤均起源于胃。在7例平滑肌瘤和2例神经鞘瘤中未检测到KIT或PDGFRA突变。总之，GIT中的大多数平滑肌瘤和少数神经鞘瘤有相当一部分KIT和DOG1阳性细胞。所有肿瘤均位于GIT上部，可存在于固有肌层或黏膜肌层。这些肿瘤代表GIT中KIT和DOG1阳性细胞的非肿瘤性增殖。仔细评估GIT梭形细胞肿瘤中的KIT或DOG1阳性细胞有助于通过与GIST鉴别形成正确诊断。
