Ectopic cervical anaplastic ependymoma.
Ependymomas generally arise in the central nervous system (CNS), although rare primary extraneural ependymomas have been observed. Reported herein for the first time is the case of a patient with primary ectopic cervical anaplastic ependymoma. The tumor was found in the right neck root region of a 35-year-old man. No additional tumor was found in the CNS or in other parts of the body. The patient received surgery and post-surgical local radiotherapy. Microscopically, the tumor consisted of round to oval cells with fine chromatin, distinct nucleoli, moderate nuclear atypia and numerous mitoses (>25/10 high-power fields) in a densely cellular growth pattern with characteristic fibrillary cytoplasm and formation of perivascular pseudorosettes. By immunohistochemistry, the tumor cells were positive for glial fibrillary acidic protein, epithelial membrane antigen (EMA), vimentin and S-100 protein. EMA staining showed a membranous as well as a paranuclear pattern of immunoreactivity. Electron microscopic studies revealed that tumor cells form micro rosettes, into which microvilli and cilia projected. The diagnosis was World Health Organization grade III anaplastic ependymoma. There is no evidence of local tumor recurrence or distant metastasis after 30 months follow up. The present case adds yet another unique example to the already diverse spectrum of head and neck neoplasms encountered in surgical pathology.