Recurrent Knee Pain in an Athletic Adult: Multiple Schwannomas Secondary to Schwannomatosis. A Case Report

Schwannomatosis has been used to describe patients with multiple nonvestibular schwannomas with no associated features of neurofibromatosis type 2. In our case, a 28-year-old athletic man underwent a right knee excisional biopsy for multifocal, benign schwannomatosis. After being asymptomatic for 4 years postresection, he returned to our musculoskeletal oncology service. Imaging studies revealed local recurrence identical to his initial presentation. Excisional biopsy of discrete masses was performed and histologic examination revealed recurrent benign schwannomatosis. To our knowledge, this is the second reported case of recurrent benign schwannomatosis. We review schwannomatosis, including its etiology, radiographic features, and relationship to neurofibromatosis.