A patient with multiple endocrine neoplasia type 1 (MEN1) who manifested various MEN1-unrelated tumors was reported. The patient was a 43-year-old woman who manifested typical features of MEN1 including primary hyperparathyroidism, prolactinoma, adrenal adenoma and visceral lipomas. During the course, she also manifested chondrosarcoma, B cell lymphoma and mesothelioma. The patient had no apparent family history of MEN1 or any other neoplastic diseases. Genetic analysis of DNA from peripheral mononuclear cells of the patient revealed no germline mutations in MEN1 gene. Genetic instability due to yet unidentified cause is the possible explanation of occurrence of multiple tumors. Careful periodic screening of endocrine and other disorders for her siblings and children as well as for the patient is warranted.