CUTANEOUS PLEXIFORM SCHWANNOMA ASSOCIATED WITH NEUROFIBROMATOSIS TYPE-2

Background. Plexiform schwannoma (PS) is a rare benign tumor of the ne rve sheath that can be located either in the deep soft tissues or in t he dermis or subcutis. The tumor predominantly affects young adults an d occurs most commonly as a slowly growing asymptomatic solitary nodul e in the head and neck region, trunk, and upper extremities. Methods. A cutaneous PS located in the preauricular region of a 19-year-old whi te female is reported. The patient exhibited six ''cafe-au-lait'' spot s in the trunk and the extremities. Magnetic resonance imaging examina tion showed bilateral tumors in both acoustic nerves (considered schwa nnomas) and also masses in the right major sphenoidal wing, fair, and T-2-T-3 level of rachis and a solid and cystic tumor in the low medull a oblongata. Tumors of the preauricular region, medulla oblongata, spi nal cord at level T-2-T-3, and major sphenoidal wing area were surgica lly removed. The tumors were studied by immunohistochemistry and diagn osed as PS, pilocytic astrocytoma, and meningiomas, respectively. Resu lts, Seventy-eight cases of PS have been reported in the literature: 8 (10.2%) have been associated with clinical schwannomatosis, 6 (7.7%) with multiple cutaneous schwannomas syndrome, and only 3 (3.8%) with n eurofibromatosis type 1 (NF-1). Conclusions. In this report, to the au thors' knowledge, for the first time PS is described associated with n eurofibromatosis type 2. The tumor does not appear to have significant association with NF-1. Plexiform schwannoma should be recognized beca use it may be misdiagnosed as plexiform neurofibroma or other plexifor m malignant tumors. Differentiation from plexiform neurofibroma is imp ortant, because the latter is virtually pathognomonic of neurofibromat osis type 1 and has a propensity for malignant transformation.