Endocrine Abstracts

Introduction: The sellar region is known as a low-risk brain metastasis area. The prevalence of pituitary metastasis represents 1% of all surgical tumors of the pituitary gland. In most cases, pituitary metastasis is identified in patients with a prior history of cancer. In a few cases, it can reveal the primary tumor. The aim of this study was to assess clinical and paraclinical features of pituitary metastasis.

Methods: This was a retrospective and descriptive study including patients with pituitary metastasis admitted to our department. Clinical, hormonal, and radiological data were collected.

Results: Five patients (four women and a man) with a mean age of 51.4 years [extremes: 32-68] were enrolled in this study. Three women had a history of metastatic ductal breast carcinoma. Two women presented with polyuria-polydipsia syndrome and the third one presented with headaches, blurred vision, and decreased visual acuity. Hormonal investigations revealed disconnection hyperprolactinemia (n=2), central diabetes insipidus (n=2), and hypopituitarism (n=3). Pituitary magnetic resonance imaging (MRI) revealed, in both women with polyuria-polydipsia syndrome, a heterogeneous thickening of the pituitary stalk. The third patient presented a large heterogeneous pituitary mass of 27 mm with supra-sellar extension and infiltration of the optic chiasm. In two patients, the primary cancer was revealed by the pituitary metastasis. The first was a 50-year-old woman who presented with headaches, visual disorders, weakness, nausea, vomiting, and hypoglycemia. Pituitary MRI showed a large mass extending from the sella turcica to the sphenoid sinus, optic chiasm, and nasopharynx. Endoscopic biopsy confirmed the diagnosis of undifferentiated nasopharyngeal carcinoma with intracranial extension. Biological investigations revealed hypopituitarism and disconnection hyperprolactinemia. The patient was put on hormone replacement therapy. After corticosteroid treatment initiation, a diabetes insipidus was revealed. The second patient was a 68-year-old man, who presented with polyuria-polydipsia syndrome. The diagnosis of central diabetes insipidus with disconnection hyperprolactinemia and hypopituitarism was established. Pituitary MRI showed a tumor of a 12 mm involving the pituitary stalk and infundibulum. The patient was diagnosed with metastatic small-cell lung cancer.

Conclusion: The hypothalamic-pituitary area is a rare site of metastasis. Clinical presentation and pituitary MRI are the key in guiding the diagnosis. Signs of dysfunction of both the anterior and the posterior pituitary gland are often present. Diabetes insipidus is the most frequent symptom.