Gastric glomus tumors (GGTs) are rare mesenchymal tumors. Most glomus tumors occur in the distal parts of the extremities. Here, we retrospectively analyzed the features of GGTs from two institutions. The histologic and clinical findings of all GGT cases from 2009 to 2018 were reviewed. The most common location was the antrum, the mean age of patients was 49.3 years, and the mean tumor size was 2.1 cm. Microscopically, small, round cell nodules surrounded the expansion of blood vessels in a nest pattern. Immunohistochemical assays for vimentin and smooth muscle actin (SMA) were positive, and assays for H-caldesmon and calponin were partially positive. GGT is rare and easily misdiagnosed before operation. However, immunohistochemistry is useful for the differential diagnosis. The majority of GGTs are benign, and local surgery achieving complete resection is the most effective treatment method.

Carcinosarcoma is a rare malignant neoplasm, consisting of both epithelial and mesenchymal component. Primary gastric carcinosarcoma is rare and poorly understood. We reported clinicopathologic features of 4 cases and analysis of 76 cases published in the literature. Clinical symptoms were nonspecific with epigastric pain, weight loss, and melena, as the most common complaints. The prognosis of patients was dismal with high mortality. The tumor commonly occurred in the upper stomach in Chinese patients, whereas, it was more prevalent at the lower stomach in Japanese and other populations. The two malignant components of this rare cancer showed considerable histological heterogeneity with a wide range of differentiation. We propose that carcinosarcomas be divided in two main subtypes: conventional carcinosarcoma and carcinosarcoma, not-otherwise-specified (NOS). Such distinction may provide useful information for targeted treatment of various sarcomatous components of this tumor. Immunohistochemistry should be routinely applied in the diagnosis of this rare tumor.

Compared with early gastric intramucosal carcinoma, submucosal carcinoma is known to have a higher risk for lymph node metastasis (LMN), but risk factors in submucosal carcinoma remain elusive. In this multicenter study with 621 radical gastrectomies for submucosal early gastric carcinoma, we investigated tumor budding and other risk factors of LMN that were identified in 172 cases (27.7%). Overall, independent high-risk factors for LMN included lymphovascular invasion (odds ratio, 3.9; 95% confidence interval, 2.5-6.1), tumor budding (odds ratio, 3.3; 95% confidence interval, 1.9-5.9), mixed tubular/papillary adenocarcinoma with poorly cohesive carcinoma (odds ratio, 2.1; 95% confidence interval, 1.0-4.3), and female sex (odds ratio, 1.6; 95% confidence interval, 1.0-2.6), whereas gastric cardiac submucosal carcinomas had a significantly lower risk for LMN (odds ratio, 0.5; 95% confidence interval, 0.3-0.9). In 276 well/moderately differentiated tubular or papillary submucosal early gastric carcinomas, independent risk factors were tumor budding (odds ratio, 3.7; 95% confidence interval, 1.6-8.7), deep submucosal (SM2) invasion (odds ratio, 3.1; 95% confidence interval, 1.3-7.6), and lymphovascular invasion (odds ratio, 2.7; 95% confidence interval, 1.3-5.6). In 174 cases without tumor budding and lymphovascular invasion, no LMN was identified in 47 cardiac tumors, and 15 tumors <1.0 cm in size. In conclusion, tumor budding, lymphovascular invasion, mixed tubular/papillary adenocarcinoma with poorly cohesive carcinoma, and female gender were found to be significant high-risk factors for LMN in submucosal early gastric carcinoma, while submucosal gastric cardiac carcinoma had a significantly lower risk for nodal metastasis.