Fluid–fluid level in peripheral nerve schwannoma: report of a case with histological correlation

Fluid–fluid level was observed in an unusual case of a 74-year-old man with peripheral nerve schwannoma of the lower extremity. To our knowledge, we found that schwannomas with imaging findings of fluid–fluid level had rarely been reported in the literature, and these tumors were all intracranial. Fluid–fluid level seen in peripheral nerve schwannoma has never been reported. In this case, MRI signal characteristics are those of blood and histological analysis of the fluid–fluid level suggests cystic degeneration with presence of intratumoral hemorrhage.