MEN1 and pituitary gland adenoma: The diagnostic investigation for MEN 1 syndrome revealed negative findings The diagnostic investigation for MEN 1 syndrome revealed negative findings, including the pituitary MRI (absence of pituitary adenoma), abdominal CT (no pancreatic or adrenal pathology), and MEN1 gene mutational analysis (negative for the causative oncosuppressor gene MEN1 at the 11q13 region).