PANHYPOPITUITARISM DUE TO BREAST CANCER METASTASIS

Resumo

Introduction: Metastases to the pituitary gland (PMs) are a rare complication in oncological patients. Estimates are that the PMs represent 0,87% of all intracranial metastases and about 1% of the resected tumors in pituitary. Here, we report a case of metastatic breast cancer, which manifested clinically as panhypopituitarism. Case report: A 68 years old woman was admitted in the university hospital of Federal University of Grand Dourados for intensive care due to sepsis with a pulmonary focus. She presented a decreased level of consciousness, panhypopituitarism and unwieldy hypernatremia, and a magnetic resonance (MRI) was performed. The MRI showed a volumetric growth in the adenohypophisis, a thickening in the pituitary stalk and also a parieto-occipital nodular lesion. A screening for the primary tumor in the chest, abdomen, pelvis and breasts was realized, but it was not found. At the follow-up, she presented weakness in the lower limbs and was not able to walk, ptosis and divergent strabismus in the left eye, mydriatic pupils and hearing impairment. The new MRI showed an increased heterogeneous mass in the pituitary, occupying intra and supra-sellar area. Then, the patient was sent for a biopsy and immunohistochemistry, which suggested that the lesion was a breast adenocarcinoma. Discussion: Breast and lung are the most common sites for the primary tumor, representing 37,2% and 24,2% of the PMs, respectively. This can be partially explained by their high prevalence. Even though the pituitary is an unusual place for metastasis of breast cancer, it may occur in 6-29% of patients. PMs usually appear in the posterior lobe, because of its direct irrigation, while the anterior lobe’s supply comes from the hypothalamic-pituitary portal system. In this case, the initial lesion was observed in the adenohypophisis. This can be explained by the tropism of the circulating breast tumor cells for this lobe’s hormone environment, since it was affected in 72-80% of the breast PMs. This case shows the importance of the follow-up even when the breast cancer is in remission. This is a disease with a high rate (8-21%) of recurrence after the primary diagnosis.