Division of Gastroenterology and Hepatology, St. Marianna University School of Medicine, Kawasaki, Japan.
World J Gastroenterol. 2012 Oct 21;18(39):5645-8. doi: 10.3748/wjg.v18.i39.5645.
We present a rare case of a gastrointestinal stromal tumor (GIST) in the stomach with prominent calcification at presentation. A 61-year-old woman visited our hospital because of epigastric discomfort. A spherical calcified lesion with a diameter of about 30 mm was incidentally shown in the left upper quadrant on an abdominal X-ray. Computed tomography demonstrated that the tumor was growing from the upper gastric body, with calcification in the peripheral ring area. A laparoscopic partial gastrectomy was performed, and the resected specimen revealed a well-circumscribed tumor with exophytic growth from the gastric muscularis propria. Microscopic examination revealed spindle-shaped tumor cells with calcification and hemorrhage. Additionally, positive immunoreactivity of the tumor to KIT and CD34 and a low mitotic index resulted in the diagnosis of very low risk GIST. There are a few case reports of heavily calcified GIST, although solitary or punctate calcification of primary GIST has been reported in several case series. Dystrophic calcification of necrotic or degenerative tissue is the supposed cause of primary calcified GISTs. In contrast, appearance of calcification after administration of imatinib mesylate, which may be one indicator of disease response, is possibly caused by a different mechanism.
我们报告了一例罕见的胃固有层间质瘤（GIST），其在表现时存在明显的钙化。一位 61 岁女性因上腹部不适就诊于我院。腹部 X 线检查偶然显示左上象限有一个直径约 30 毫米的球形钙化病变。计算机断层扫描显示肿瘤从胃上部生长，外周环区有钙化。行腹腔镜胃部分切除术，切除标本显示从胃固有肌层向外生长的边界清楚的肿瘤。显微镜下观察显示有钙化和出血的梭形肿瘤细胞。此外，肿瘤对 KIT 和 CD34 的免疫反应阳性，且有低有丝分裂指数，导致诊断为极低风险 GIST。尽管已有几例关于原发性 GIST 单发或点状钙化的病例报道，但存在少数重度钙化 GIST 的病例报告。推测原发性钙化 GIST 的原因是坏死或退行性组织的营养不良性钙化。相比之下，甲磺酸伊马替尼治疗后出现钙化，这可能是疾病反应的一个指标，其出现的机制可能不同。
