Pituitary and pineal gland metastases from pulmonary neuroendocrine carcinoma: A case report and literature review.

Neuroendocrine neoplasms are a group of tumors originating from neuroendocrine cells that can occur in endocrine or non-endocrine organs. Metastatic pituitary neuroendocrine carcinomas are uncommon in clinical practice, with female breast cancer and male lung cancer being the most common primary sources of pituitary metastases. Pituitary and pineal gland metastases from pulmonary neuroendocrine tumors are extremely rare. The current study describes the case of a 68-year-old male patient who first presented with a headache and a small and limited pituitary lesion on saddle MRI, which was initially considered to be a primary pituitary microadenoma and was recommended to be reviewed on an ongoing basis. A total of 4 months later, the patient presented again after worsening of the headache and visual disturbances with diabetes insipidus. On review of the saddle MRI, which showed a significantly enlarged pituitary and pineal regions, the patient was treated with transsphenoidal surgery to completely excise the tumor. However, histopathological and immunohistochemical results suggested a pituitary metastasis from a pulmonary neuroendocrine tumor. Although the pineal region lesion did not undergo surgical pathology to confirm its origin from a pulmonary neuroendocrine tumor, it was highly suspected to be homologous to a pituitary metastasis in combination with the monist diagnostic and treatment concepts, and the imaging manifestations of the lesion. This case highlights the importance of the differential diagnosis of invasive lesions in the saddle region combined with the pineal region. Clinicians should be alert to this rare disease and a multidisciplinary consultation should be performed should be performed.