Abstract 2- 0915-0930
At the end of the session,
participants will be able to:
- Understand the principal neuropathological feature that distinguishes primitive neuroblastoma from ganglioneuroblastoma
- Recognize the immunocytochemical neuronal markers that are useful in identifying ganglion cell differentiation from neuroepithelial cells in peripheral neuroblastic tumours
- Understand that PHOX2B is a specific marker of peripheral neuroblastic tumours but that it does not distinguish stages of maturation of ganglion cells
Dr. Sarnat is Professor of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences at the University of Calgary (Canada), where he has practiced since 1981 except for a decade spent on faculty at the University of Washington (Seattle) and then UCLA (Los Angeles), returning to Calgary in 2004.
Harvey B. Sarnat University of Calgary & Alberta Children’s Hospital, Calgary, Alberta
Pathologists, Residents, Paediatric Oncologists
Medical Expert (the integrating role), Scholar
Ganglion Cell Maturational Markers in Peripheral Neuroblastic Tumours of Children
Peripheral neuroblastic tumours of neural crest origin are the most frequent solid neoplasms outside the CNS in children. Neuroblastoma/ganglioneuroblastoma have a natural evolution of histological differentiation over time. Together with mitosis-karyorrhexis index and patient age (International Neuroblastoma Pathology Classification criteria), ganglion cell maturation determines grading and prognosis. Maturation presently is assessed only by H&E histology. Methods: Immunocytochemical markers of neuroblast maturation in fetal CNS were applied to peripheral neuroblastic tumours arising in adrenal medulla or sympathetic chain. Resected tumours of 4 toddlers were examined using antibodies demonstrating neuronal identity and maturation: MAP2; synaptophysin; chromogranin-A; NeuN; keratan sulfate (KS); glutamate receptor antibody (GluR2). Others: Ki67; S-100Î² protein; vimentin; nestin; Î±-B-crystallin; neuroblastoma marker PHOX2B. Results: Degrees of neuroblastic maturation were demonstrated by MAP2, chromogranin, synaptophysin, KS and GluR2; NeuN was negative consistent with sympathetic neural crest lineage. KS was sparsely distributed within the tumours adherent to somata and proximal neuritic trunks. PHOX2B did not distinguish maturational stages. KI67 was expressed in scattered primitive cells that also expressed vimentin and nestin, but not in differentiated neoplastic neurons. S-100Î² protein and Î±-B-crystallin labeled Schwann cells, especially Schwannian ganglioneuroma. Conclusions: Immunocytochemical markers of neuroblast maturation in fetal brain also are useful in peripheral neuroblastic tumours, providing greater precision than histology alone. The most practical are MAP2 and synaptophysin. Prognosis and choice of treatment including chemotherapy might be influenced.