Tumors Metastatic to the Pituitary Gland: Case Report and Literature Review

Tumors metastatic to the pituitary gland are an unusual complication of systemic cancer typically seen in elderly patients with diffuse malignant disease. Breast and lung are the commonest sites of the primary tumor, whereas diabetes insipidus is the most frequent symptom at presentation. Their rarity and usually indolent course, as well as the lack of specific clinical and radiological features, impede their differentiation from other more common sellar area lesions, particularly when history of malignancy is absent. Management of these patients may also be very difficult because the prognosis depends on the course of the primary neoplasm. A 68-yr-old man, with no history of malignancy, presented with recent onset of hypopituitarism, mild diabetes insipidus, headaches, left oculomotor nerve palsy, and progressive bilateral deterioration of visual acuity and visual fields. Magnetic resonance imaging revealed a large sellar mass compressing the optic chiasm and invading the left cavernous sinus, whereas a prolactin elevation at 438.6 ng/ml (19.73 nmol/liter) was noted. Decompression of the sellar region was attempted, and pathology disclosed a metastatic hepatocellular carcinoma. On postoperative investigation, primary liver tumor was identified and confirmed by biopsy. The patient improved transiently but died 3 months after diagnosis because of deterioration of the liver disease. The relevant literature is reviewed in light of this unusual case, illustrating the problems in the diagnosis and management of patients with metastasis to the pituitary.