Metastatic Pituitary Carcinoma Causing Cord Compression

A 39-year-old man with a history of recurrent pituitary tumor, Cushing disease, and Nelson syndrome presented with neck stiffness. He previously had bilateral adrenalectomy and hypophysectomy 27 years ago. He subsequently had repeat pituitary surgery, stereotactic radiosurgery, and chemotherapy for recurrent pituitary tumor. During follow-up, he was noted to have rising basal adrenocorticotrophin (ACTH) level. On examination, he was neurologically intact with no signs of myelopathy. Magnetic resonance imaging of the spine showed a large intradural extramedullary lesion causing cord compression at the C2-3 level. He underwent a cervical laminectomy and debulking of the lesion under continuous monitoring of motor-evoked and somatosensory-evoked potentials. He remained neurologically intact postoperatively. Histologic analysis revealed a tumor of pituitary origin with synaptophysin and ACTH expression. Pituitary drop metastasis is a rare entity and should raise a high index of suspicion given this clinical presentation. The radiologic appearance can mimic benign lesions such as meningioma or schwannoma.