Multifocal uterine myxoid change: a newly recognized association with neurofibromatosis type 1.

Stromal myxoid change is a rare feature of non-neoplastic disease of the uterus. "Myometrial myxoidosis" with secondary myometrial hypertrophy was reported in 2 patients with systemic lupus erythematosus. Uterine myxoid stromal change was also described as an unusual pseudoneoplastic condition of uncertain etiology in 3 patients, one of whom had neurofibromatosis type 1 (NF1; von Recklinghausen disease). We have now identified multifocal uterine myxoid change in the hysterectomy specimen of another patient with NF1; we describe the findings in both patients and review the relevant literature. The myometrium and cervical stroma in both NF1 patients contained tracts and nodules of hypocellular myxoid stromal material composed of bland spindle-shaped cells and interspersed small blood vessels. The myxoid stromal material was strongly and diffusely immunopositive for CD34 and CD10 but did not label for desmin, smooth muscle actin, h-caldesmon, neurofilament protein, S100, or epithelial membrane antigen. The myxoid material in the NF1 patients was better demarcated than in the 2 reported cases of myometrial myxoidosis in systemic lupus erythematosus, and more widely distributed, extensively involving the cervix and the myometrium. The occurrence of this rare, distinctive pattern of multifocal uterine myxoid change in 2 patients with NF1 seems unlikely to represent simply a chance association. The identification of multifocal uterine myxoid change in non-neoplastic myometrium or cervical stroma should raise the possibility of underlying NF1.