Pituitary lesions in breast cancer patients: A report of three cases

Pituitary metastases occur in 6-8% of breast cancer cases, but are seldom diagnosed and rarely reported. Therefore, it can be challenging to establish a clinical differential diagnosis, and at present, a definitive criteria is not available. The present study discusses the pituitary lesions identified in three patients with breast cancer, and describes their management within the collaborative framework of the Breast Unit at the Citta della Salute Hospital, which also included assessment by endocrinologists. The patients were evaluated for anterior and posterior pituitary function, the appearance of the pituitary upon magnetic resonance imaging (MRI), and the oncology status and treatment. In addition, successive analysis of prolactin levels and the MRI was performed. The patients, aged 75, 83 and 76 years old, differed in their clinical presentation and successive evolution. One patient demonstrated an abrupt onset of diabetes insipidus, the second exhibited overt hypopituitarism and the final patient had a pituitary mass discovered by chance. Cases one and three exhibited systemic spread of the breast cancer, with bone and/or parenchymal metastasis, but not brain metastasis. Case two presented with a secondary pituitary tumour alone. In case three, a secondary nature to the pituitary lesion was unlikely, since there was no lesion evolution evident following MRI and as stable prolactin levels were observed over the course of the study period. By contrast, case one presented with a rapid increase of sellar lesions on MRI, together with a progressive rise in prolactin levels. Taking into account the frailty of breast cancer patients who are monitored for disease progression, management in a collaborative framework, such as at the Breast Unit, makes it possible to establish a diagnosis of sellar lesions, which is adequate for the comprehensive management of the patient with successive pituitary MRIs and prolactin evaluations, and avoids unnecessary invasive neurosurgery.