Metastatic pulmonary tumor from type 3 gastric neuroendocrine tumor

• Main Authors: Shuta Ohara, Atsushi Yasuda, Shigeki Shimizu, Kenichi Suda, Tetsuya Mitsudomi
• Format: Article
• Language: English
• Published: Elsevier 2021-03-01
• Series: Human Pathology: Case Reports
• Subjects: Metastatic pulmonary carcinoid; Gastric endocrine cell tumor; Submucosal tumor; Thyroid transcription factor-1
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214330021000109

Type 3 NETs are reported to metastasize to other organs or lymph nodes; however, there are few reports of gastric NETs causing isolated pulmonary metastasis. We report a rare case of primary gastric neuroendocrine tumors (NETs) with lung metastasis. The patient presented with multiple gastric submucosal tumors (SMTs) and a solid nodule in the S1 + 2 of the left lung. Endoscopic mucosal resection of the stomach and a left upper lobectomy of the lung were successfully performed. The histopathological findings of the gastric SMTs and lung tumor revealed type 3 gastric NETs and a metastatic pulmonary tumor, although TTF-1 is positive in the stomach and the lung. In this time, we reported a rare case of a metastatic pulmonary tumor from gastric type 3 NETs. In addition, we also realized the limitations of immunohistochemistry in identifying the site of origin for NETs and the need to rely on morphologic and clinical features.