Gastric carcinoid with metastasis to a regional lymph node in a dog: case report.

Gastric neuroendocrine neoplasms (NENs), historically termed gastric carcinoids, are rare in dogs and poorly characterized in veterinary medicine. A 13-year-old spayed female Maltese dog was evaluated for an incidentally detected abdominal mass. Computed tomography revealed a contrast-enhancing gastric body mass and an enlarged regional lymph node suspicious for metastasis. Surgical excision and histopathology confirmed a well-differentiated gastric NEN with regional lymph node metastasis. Immunohistochemical findings supported neuroendocrine differentiation and helped exclude major differential diagnoses. Despite relatively low mitotic activity and an intermediate proliferative index, metastatic spread was documented. This case highlights that histologically well-differentiated canine gastric NENs may exhibit malignant behavior and emphasizes the importance of thorough nodal assessment for accurate staging.