Mucin-secreting gastric adenocarcinoma with Rhabdoid areas

SMARCB1/INI1-Deficient Poorly Differentiated Carcinoma of the Colon With Rhabdoid Features-A Rare Tumor With Serrated Phenotype: Case Report and Review of Literature

Poorly differentiated colonic carcinoma with rhabdoid features is a rarely described entity. Our knowledge regarding the molecular phenotype of the tumor is evolving. We herein report a similar tumor with rhabdoid differentiation identified in the splenic flexure, which on histological examination showed a poorly differentiated phenotype with epithelioid to spindled morphology, tumor giant cells, and rhabdoid differentiation. The tumor was mismatch repair-proficient, deficient of INI1/SMARCB1, KRAS mutated (A146×), BRAFV600E mutated (c.1799T > A), and NRAS wild-type, indicating serrated differentiation in the tumor. The patient died after 3.5 months post-surgery. INI1-deficient poorly differentiated carcinoma of the colon is a rare, aggressive colonic malignancy showing a serrated phenotype. Routine identification and subtyping are important keeping in mind the distinct tumor phenotype, resistance to conventional chemotherapy, and dismal prognosis.

Switch/Sucrose Non-Fermentable Complex-Deficient Rhabdoid Carcinoma of Stomach: A Rare Case Report and Literature Review

Gastric undifferentiated/rhabdoid carcinoma is a rare highly invasive tumor of epithelial origin. Due to mutations in the switch/sucrose non-fermentable (SWI/SNF) complex, these tumor cells are usually dedifferentiated, presenting a characteristic rhabdoid profile. In this report, we present a gastric rhabdoid carcinoma in a 77-year-old man who presented with intermittent epigastric pain. Gastroscopy revealed a giant ulcer in the antrum, which proved to be a malignant tumor in the biopsy. Therefore, he was admitted to our hospital and underwent laparoscopic radical gastrectomy and D2 lymphadenectomy. The resected neoplasm contained a variety of rhabdoid cells that lacked well-differentiated elements. Immunohistochemical staining revealed that SMARCA4/BRG1 expression was absent in tumor cells. Finally, the patient was diagnosed with undifferentiated/rhabdoid carcinoma of the stomach. The patient was treated with tegafur-gimeracil-oteracil potassium capsules postoperatively. There were no signs of imaging changes observed at the 18-month follow-up. We reviewed similar cases in previous reports. These tumors are more likely to affect older male adults and usually lack typical symptoms. Histologically, most tumor cells are poorly cohesive and rhabdoid, and differentiated compositions of various degrees can occasionally be seen. Positive staining for vimentin was seen in all tumor cells. Epithelial markers are positive in the majority of tumors. SWI/SNF mutant tumors tend to be associated with a poor prognosis. In this review, more than half of the patients died within one year after surgery. The treatments for these diseases are still being explored.

Imaging Findings of a Malignant Rhabdoid Tumor in the Stomach: A Case Report

악성 횡문근양 종양은 주로 영유아의 신장에서 발생하는 공격적인 종양이다. 신장 이외의 조직에서 발생한 경우 신외성 악성 횡문근양 종양이라 하고 중추신경계, 간, 뇌, 피부, 연조직 등에서 드물게 보고되었다. 위에서 발생한 악성 횡문근양 종양은 매우 드물다. 저자들은 흑색변을 주소로 내원한 72세 남자의 위에서 발견된 악성 신외성 횡문근양 종양이 림프종과 유사한 영상 소견을 보인 예를 경험하여 보고한다.

Gastric adenocarcinoma with rhabdoid morphology

Extrarenal rhabdoid tumors (ERRTs) are very rare neoplasms and have been reported in a range of organs, including sixteen cases in the stomach. We describe a woman aged 86 years who had an advanced gastric tumor with lymph node metastasis. The tumor mostly showed a diffuse arrangement with a small glandular region. The tumor cells were non-cohesive and had polygonal morphology with eccentric vesicular nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm, i.e. they showed rhabdoid features. Immunohistochemically, the rhabdoid tumor cells were strongly positive for cytokeratins and vimentin. However, a candidate tumor suppressor gene of rhabdoid tumors, the INI1 gene, showed no mutations or loss of expression in the tumor cells. Although ERRTs typically have an aggressive clinical course, the patient was still alive without any evidence of recurrence or metastasis at 26 months after surgery. The rhabdoid features of the present case seemed to be a variant of gastric adenocarcinoma.