Although rare, metastatic involvement of the pituitary gland has been reported with increasing frequency during the last decades. Pituitary metastasis can be the initial presentation of an otherwise unknown malignancy and should be considered in the differential diagnosis of pituitary lesions, irrespective of a history of malignancy. The sudden onset and rapid progression of visual or endocrine dysfunction from a pituitary lesion should strongly raise the suspicion of metastatic disease. MRI features of pituitary metastasis can overlap with those of other pituitary lesions, including hypophysitis; however, rapid pituitary growth is highly suggestive of metastatic disease. Survival after pituitary metastasis detection has improved over time, encouraging individualized interventions directed to metastasis to improve quality of life and increase survival 1).
Pituitary metastases (PM) is a rare complication of advanced malignancy, first reported by L. Benjamin in 1857 as a case of melanoma spread to the pituitary identified in an autopsy 2) and later in 1913, Cushing 3) reported this unique phenomenon as the cause of diabetes insipidus.
The most common primary malignancies to be found in the pituitary are breast cancer in women and lung cancer in men, presumably merely due to a large number of cerebral metastases from these two cancers . Many other primary tumours have also been described.
It is interesting to note that the posterior lobe and the infundibulum of the pituitary gland are more frequently involved than the anterior lobe (although this may not be the case in breast cancer). Presumably due to the fact that the anterior pituitary receives its blood via the portal circulation rather than directly from the hypophyseal arteries.
A systematic review was performed according to PRISMA recommendations. All cases of MP were included, excepted primary pituitary neoplasms and autopsy reports. Descriptive and survival analyses were then conducted.
The search identified 2143 records, of which 157 were included. A total of 657 cases of MP were reported, including 334 females (50.8%). The mean ± standard deviation age was 59.1 ± 11.9 years. Lung cancer was the most frequent primary site (31.0%), followed by breast (26.2%) and kidney cancers (8.1%). Median survival from MP diagnosis was 14 months. Overall survival was significantly different between lung, breast and kidney cancers (P < .0001). Survival was impacted by radiotherapy (hazard ratio (HR) 0.49; 95% confidence interval (CI) 0.35-0.67; P < .0001) and chemotherapy (HR 0.58; 95% CI 0.36-0.92; P = .013) but not by surgery. Stereotactic radiotherapy tended to improve survival over conventional radiotherapy (HR 0.66; 95% CI 0.39-1.12; P = .065). Patients from recent studies (≥ 2010) had longer survival than others (HR 1.36; 95% CI 1.05-1.76; P = .0019).
This systematic review based on 657 cases helped to better identify clinical features, oncological characteristics, and the effect of current therapies in patients with MP. Survival patterns were conditioned upon primary cancer histologies, the use of local radiotherapy and systemic chemotherapy, but not by surgery 4)