T2-hyperintensity Signal along the Optic Tract in Pituitary Metastasis: Case Report

This study reports a case of a 56-year-old man with a past medical history of lung adenocarcinoma who presented with worsening headaches and blurry vision. Laboratory evaluation confirmed the diagnosis of hypopituitarism and diabetes insipidus. Magnetic resonance imaging of the brain revealed an enhancing mass in the sella extending into the suprasellar cistern with mass effect on the optic nerves and increased T2/FLAIR signal intensity mimicking edema in the optic tracts. Surgical resection of the lesion was performed via an endoscopic endonasal approach. Pathology showed malignant neoplasm, most consistent with a metastatic carcinoma. The presence of edema-like change has been linked to the enlargement of perivascular spaces along the optic tract. It is mostly associated with craniopharyngioma; however, with development of higher quality images, this finding has more often been observed in other sellar tumors such as pituitary adenoma, germ cell tumor, malignant lymphoma, pituitary metastasis, and Rathke’s cleft cyst. This edema-like change in the optic tracts has rarely been reported with metastatic tumors in the sellar region. Our case is an example of the fact that edema-like change is not specific to certain pathology and is observed in sellar region tumors mainly located posterior to optic chiasm obstructing the fluid drainage of the PV spaces along the optic tracts.