Overview
Primitive neuroectodermal tumors (PNET) encompass a heterogeneous group of small, round-cell tumors arising primarily in the central nervous system (CNS) and occasionally in peripheral sites. These tumors are rare in adults, with most cases reported in pediatric populations. 12Diagnosis
Imaging: MRI is essential for identifying lesions, often showing supratentorial, periventricular, or localized masses. 1
Histology: Definitive diagnosis requires histopathological examination, often showing small, uniform cells.
Immunohistochemistry: CD99 positivity can support diagnosis; FISH for t(11;22) translocation aids in distinguishing central from peripheral PNETs. 1
Grading: Not explicitly detailed in provided abstracts; typically follows WHO grading system for CNS tumors.Management
Surgical Resection: Primary treatment involves complete surgical resection when feasible. 1
Radiation Therapy: Post-surgical radiation therapy is commonly employed, though efficacy varies. 1
Chemotherapy: Specific drug classes and doses are not detailed in the abstracts; regimens may include agents targeting small cell tumors. 2Special Populations
Adults: Adult cases are exceedingly rare, with limited data on specific management approaches beyond surgical and radiation interventions. 1
Pediatrics: While not extensively covered in the abstracts, PNETs are more commonly diagnosed in children, suggesting pediatric-specific protocols may exist but are not detailed here. 2Key Recommendations
Utilize MRI for initial imaging to accurately localize PNET lesions. (Evidence: Moderate 1)
Confirm diagnosis with histopathological examination complemented by CD99 immunohistochemistry and FISH for translocation analysis when possible. (Evidence: Weak 1)
Employ surgical resection as the primary treatment approach, followed by radiation therapy post-surgery, acknowledging variable outcomes. (Evidence: Expert opinion 1)References
1 Ohba S, Yoshida K, Hirose Y, Ikeda E, Kawase T. A supratentorial primitive neuroectodermal tumor in an adult: a case report and review of the literature. Journal of neuro-oncology 2008. link
2 Dehner LP. Peripheral and central primitive neuroectodermal tumors. A nosologic concept seeking a consensus. Archives of pathology & laboratory medicine 1986. link