Von Recklinghausen neurofibromatosis and hematologic malignancies: 2 case reports in adulthood.

Von Recklinghausen's neurofibromatosis is a hereditary disease predisposing to distinctive malignant hemopathies. These often develop during early childhood and are characterized by particular cytologic subtypes: juvenile chronic myeloid leukemia, monosomy 7-associated myeloproliferative syndrome and myelomonocytic leukemia. The etiopathologic mechanism underlying this association begins to be elucidated: the neurofibromatosis gene behaves like a tumor suppressor gene; its inactivation by mutation results in activation of the corresponding oncogenes. We report here the cases of two late-aged adults with neurofibromatosis: the first developed acute myelogenous leukemia, the second polycythemia vera. Based on a review of the literature, we suggest that, in opposition to childhood, the association between neurofibromatosis and malignant blood diseases is not demonstrated in adulthood.