J Neurol Surg B Skull Base 2016; 77 - PD012
DOI: 10.1055/s-0036-1579943

Clinicopathologic Features of Men1 Neoplasms

Desmond A. Brown 1, Lydia P. Wheeler 1, Brittny T. Major 2, Naykky Singh Ospina 2, Jamie J. Van Gompel 2
  • 1Mayo Clinic Department of Neurological Surgery
  • 2Mayo Clinic

Introduction: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder attributed to a germline mutation of the tumor suppressor Menin gene. It manifests as the combination of parathyroid, gastrointestinal/thoracic neuroendocrine, adrenal and pituitary tumors. While the greatest mortality in MEN1 is attributable to metastatic neuroendocrine lesions, pituitary involvement remains a significant source of both morbidity and mortality. There is controversy regarding the incidence, clinical features, pathology and outcome of pituitary disease in MEN1 patients.

Methods: A prospectively collected internal database was used to identify patients with a clinical diagnosis of MEN1 treated at our institution between 1970 and 2014.

Results: There were 280 MEN1 patients comprised of 162 (57.9%) females and 118 (42.1%) males. Among this cohort, there were 147 (53.1%) individuals with anterior pituitary tumors, 48 (33.3%) of whom underwent surgery. There was a higher prevalence of MEN1-related pituitary tumors in women than in men (62.3% vs. 42.0%, P = 0.003).

Macroadenomas were more likely to be symptomatic and locally aggressive. Functional tumors tended to be macroadenomas and prolactinomas were the modal type accounting for 75.3%. Plurihormonal tumors were twice as likely in males with an odds ratio of 2.04 and occurred significantly earlier (35.0 ± 16.0 versus 56.0 ± 8.07, P<0.05).

Kaplan-Meier analysis was used to determine the delay to a second feature given a known index neoplasm. For an index pituitary adenoma, the median time to a subsequent feature is 2.84 years versus 11.41 and 14.58 years for index pancreatic and parathyroid neoplasms, respectively (log-rank p = 0.001).

Conclusion: Pituitary disease in MEN1 mirrors that of sporadic cases with a high proportion of prolactinomas. Women are at higher risk for pituitary involvement. The timing of onset of index features of the syndrome is predictive of the order in which subsequent features develop and could be used in patient counseling and follow-up.