Gastric Salivary Gland Heterotopia

A 77-year-old male presented with epigastric discomfort. Contrast-enhanced abdominal computed tomography revealed a non-enhancing mass in the gastric cardia (Figure 1A, yellow arrow). Upper gastrointestinal endoscopy demonstrated a submucosal tumor at the same location without erosion or ulceration (Figure 1B). Endoscopic ultrasonography demonstrated a hypoechoic lesion measuring approximately 1.2 cm in diameter, located within the submucosal layer (Figure 1C). As the nature of the lesion could not be clearly determined, endoscopic submucosal dissection was performed to ensure complete resection. Histological examination (Figure 2) revealed gastric epithelium (red arrow) and lobular structures (black arrow) with ducts (green arrow) located in the submucosa, which were distinct from gastric glands. These lobular structures were composed of mucinous acini. Alcian Blue/Periodic Acid-Schiff (AB/PAS) staining (Figure 3) revealed acidic mucins within the acini (yellow arrow), in contrast to the neutral mucins present in gastric glands (blue arrow), indicating different tissue origins. On high-power magnification, the acinar architecture closely resembled that of salivary gland tissue, without evidence of cytological atypia (Figure 4A). Immunohistochemistry revealed that the acini were negative for MUC5AC and MUC6 (Figure 4B, C), and calponin-positive myoepithelial cells were observed surrounding the acini (Figure 4D). Based on these histological and immunohistochemical features, a definitive diagnosis of gastric salivary gland heterotopia was established. The patient recovered fully and showed no evidence of recurrence during follow-up. (A) A non-enhancing mass (yellow arrow) was identified in the gastric cardia on abdominal computed tomography. (B) Upper gastrointestinal endoscopy revealed a submucosal tumor in the gastric cardia. (C) Endoscopic ultrasonography demonstrated a hypoechoic mass in the submucosal layer, approximately 1.2 cm in size. Hematoxylin-Eosin staining revealed gastric epithelium (red arrow), and lobular structures (black arrow) with ducts (green arrow) in the submucosa. Alcian Blue/Periodic Acid-Schiff (AB/PAS) staining confirmed acidic mucins in acini (yellow arrow), contrasting with the neutral mucins of gastric glands (blue arrow). (A) High-power magnification revealed an acinar architecture closely resembling that of salivary gland tissue, without evidence of cytological atypia. (B–D) The acini were negative for MUC5AC and MUC6, while calponin-positive myoepithelial cells were observed surrounding the acini. Gastric salivary gland heterotopia is a rare condition likely originating from developmental anomalies or metaplastic processes 1, 2. It may present as a choristoma and can be misdiagnosed endoscopically as lymphomas, gastrointestinal stromal tumors, or leiomyomas 3. Histopathological examination is essential for diagnosis. We are grateful to Dr. Qing-ke Huang and Dr. Hua-qin Guan from the Department of Gastroenterology, the First Affiliated Hospital of Wenzhou Medical University, for their significant contributions to the clinical management of the patient. Written informed consent was obtained from the patient. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.