Metastatic tumors of the pituitary gland are very rare, representing only 1% of the pituitary mass submitted to surgeries, and are frequently related to primary neoplasia of breast and lung 1,2 .
CASEA 50-year-old male patient sought medical care complaining of cephalalgia for 4 months, diplopia and ptosis of the left eyelid for 30 days. He reported loss of libido and erectile dysfunction in the previous six months. He was before a salutary individual. Physical examination: body mass index (BMI) 24, with ptosis and ophthalmoplegia of the left eye, arterial pressure of 140/80 mmHg. No other alterations.Magnetic resonance imaging ( Figure) showed heterogeneous mass into the sella turcica with suprasellar extension, causing displacement of optic chiasm and third ventricle floor, with intense opacification after contrast.The laboratory exams showed normal thyroid function, low levels of gonadotropins and total testosterone, normal levels of basal cortisol and IGF-1 and very small increase in serum prolactin. Renal function, serum sodium and urine density were within normal limits. Central hypogonadism and slight hyperprolactinemia were detected, without evidence of posterior pituitary alteration.An endoscopic transsphenoidal pituitary surgery were performed and anatomopathological exam showed metastasis of moderately differentiated adenocarcinoma of unknown primary site. Postoperative exams showed anemia, increased GGt, FA and CA 19-9. Immunohistochemical analysis indicated origin in the gastrointestinal tract, imaging of thorax and abdomen showed lymphadenopathies and small irregularities on the antral mucosa wall of the stomach. Upper gastrointestinal endoscopy with biopsy showed stomach antral adenocarcinoma.
DISCUSSIONMetastatic tumors of the pituitary gland are rare complications 1 that occur between 1 and 3.6% of the patients with malign tumors 2 and represent between 0.14 and 28.1% of the brain metastases 3 .The metastasis reported here is from a gastric adenocarcinoma. In literature, the primary neoplasias more commonly associated with pituitary metastases are breast and lung cancer, corresponding to 30-47% and 19-30% of all cases, respectively. Other sites were reported with lower frequency [1][2][3][4][5] .The patient in question had no previous malignant history, in agreement with literature data which state that metastases may be the first manifestation of a malign tumor 1,2 . Pituitary metastases are symptomatic in only 7% of the cases 1,2 , with predominance of Diabetes insipidus (DI) [3][4][5] . This is an important characteristics in the differential diagnosis of invasive sellar lesions, as DI occurs in less than 1% of non-functioning pituitary adenomas in the first manifestation 2 . The patient in question did not present any clinical and laboratorial evidence of DI.Pituitary metastases may have symptoms caused