Secreting Follicle-Stimulating Hormone Pituitary Carcinoma with Cervical Metastasis

Pituitary carcinoma is defined by either metastases outside the central nervous system or noncontiguous foci within the central nervous system. This case report details the first documented case of a pathologically isolated follicle-stimulating hormone-secreting pituitary carcinoma and its presentation of metastasis.

A 63-year-old man developed intrascapular pain radiating up his neck to his occiput. He had undergone a transsphenoidal hypophysectomy 2 years previously for an atypical pituitary macroadenoma. Subsequent magnetic resonance imaging identified a focal, solitary, well-circumscribed, homogeneous T2 high-signal intradural, extramedullary enhancing mass at C2-3 in a right ventral parasagittal location, extending toward the exit foramina. On surgical excision with a laminectomy, the mass demonstrated a morphologic appearance of a malignant neuroendocrine tumor with an immunoprofile similar to the original atypical pituitary adenoma. This was in keeping with metastatic disease secondary to a follicle-stimulating hormone-secreting pituitary carcinoma.

Although rare, metastatic spread is recognized in patients with atypical pituitary adenoma. This should form the differential diagnosis for such patients presenting with symptoms that could be attributed to metastatic lesions within the neuraxis. In these patients, who undergo regular surveillance in joint neuroendocrine clinics, more urgent investigation of new spinal pain should be instigated to exclude metastatic disease.