Metastatic bronchial neuroendocrine tumor to the pineal gland: a unique manifestation of a rare disease.

Metastatic Neuroendocrine Tumor (NET) to the pineal gland is a unique manifestation previously unreported in the literature. We describe an unusual case of metastatic bronchial NET to the pineal gland in a 71-year-old male patient. His primary NET had been resected six years previously and there was no indication of the presence of disseminated metastatic disease at that time. Due to increased uptake by the pituitary gland on the post-operative 111Indium-pentetreotide scintigraphy (Octreoscan), an intra-sellar mass was diagnosed and excised using a transsphenoidal approach; histology revealed an unrelated non-functional pituitary macroadenoma. Four years later, a new mass appeared on MRI, involving the pineal gland, and was diagnosed on biopsy as a metastatic lesion from the original bronchial NET. Since this lesion was not accessible to surgery, it was treated successfully with radiosurgery. The case suggests that NETs should be considered in the differential diagnosis of pineal gland metastases and that radiosurgery may be an effective alternative in the treatment of these patients.