Peculiar endoneurial myxomatous matrix-collagen nodule in a patient with neurofibromatosis type 1.

Abstract

An 8-year-old girl presented with an 18-month history of right buttock gradual swelling, accompanied by increased urination and defecation frequency for 2 weeks. A physical examination revealed a cafe au lait spot from the lumbosacral region to the right buttock (Fig. 1A). Magnetic resonance imaging (MRI) demonstrated multiple ring or half-ring nodules in the pelvic cavity and the right buttock, which formed the target sign (Fig. 1B–D). Some nodules were distributed along the nerve fiber bundle directions.