A Gastric Composite Tumor with an Adenocarcinoma and a Neuroendocrine Carcinoma: A Case Report

Abstract

A 70-year-old woman was admitted to our department with epigastric discomfort and nausea over the duration of 1 month. An esophagogastroduodenoscopy showed the presence of a 1.0×1.0 cm-sized flat lesion with central ulceration at the greater curvature side of the antrum. A biopsy demonstrated the presence of an adenocarcinoma of well differentiated, intestinal type in the stomach. Endoscopic submucosal dissection was done and the diagnosis of a composite neuroendocrine carcinoma with an adenocarcinoma of the stomach was confirmed. We report a case of a gastric composite tumor with an adenocarcinoma and neuroendocrine carcinoma confirmed by endoscopic submucosal dissection with a review of the literature.

Mast cell and plasma cell collision tumor in the spleen of a dog

“…Although some definitions imply a diagnosis of collision tumor requires histopathology, this case provides compelling support that in some instances a collision tumor can be diagnosed cytologically. The cytology smears collected from each splenic mass showed an intimate association, and intermingling of neoplastic mast cells and plasma cells supporting that 2 distinct neoplasms coexisted in the same anatomic location; this meets the definition of collision tumor described in the majority of articles reviewed …”

“…In the majority of articles reviewed, a collision tumor is defined as the coexistence of 2 or more completely distinct cell types. independent neoplasms adjacent to each other at the same anatomic site . The coexistence often results in intermingling of cellular growth which is described as “collision” …”

“…A collision tumor should be differentiated from a composite/complex or mixed tumor, which is a tumor arising from one cell type or clone that differentiates into 2 or more distinct cell lineages (eg, canine mammary carcinoma‐complex type, canine mammary carcinoma‐mixed type) . This is important since this may have an impact on patient management/treatment.…”

Intramucosal Gastric Mixed Adenoneuroendocrine Carcinoma Completely Resected with Endoscopic Submucosal Dissection

“…Even in the early stage of the disease, the neuroendocrine carcinoma component is detected in the deeper portion of the mucosal or submucosal layers (8)(9)(10), suggesting that most cases of MANEC are diagnosed as advanced carcinoma. In the current case, biopsy specimens of the tumor showed only adenocarcinoma, as the neuroendocrine carcinoma component was primarily located in the deeper portion of the mucosal layer and the superficial layer of the neuroendocrine carcinoma was covered with nonneoplastic mucosa or adenocarcinoma.…”

“…Three patients with early gastric MANEC treated with ESD have been reported in Asian countries (8)(9)(10). In each case, all tumors had invaded the submucosal layer.…”