#2: Brain and CNS
Source 1: Subject matter expert
Histology--Brain and CNS: What morphology code should be assigned to a low-grade glial/glioneuronal neoplasm? See Discussion.
Pathology Diagnosis: Left temporal lesion - Low grade glial/glioneuronal neoplasm BRAF mutant. Pathologist Comment: The histopathological appearance of this lesion does not allow for a definitive diagnosis. However, the low-grade appearance, fibrillary nature, immunohistochemical profile, and the presence of a BRAF V600E mutation allow this to be categorized as a low-grade glial or possibly glioneuronal tumor. Despite the lack of exact classification this neoplasm can be expected to behave in a very indolent manner consistent with a WHO grade I classification.
Assign 9413/0 for glioneuronal neoplasm.
We consulted with our expert neuropathologist about the histology "glioneuronal neoplasm." This term is relatively new and has not yet been recognized by WHO or assigned an ICD-O code. Until such time that WHO determines a code for this neoplasm, our expert instructed us to use 9413/0. Since this is not a recognized neoplasm it is not included in the solid tumor rules.