* More anatomical information is needed before determining whether a lesion at this location is infra- or supratentorial.

ICD-O-3 Coding Issues

For some histologic types, it is difficult to determine if the primary site is intracranial or the skull (C41.0). Tumors that originate in the skull are not intracranial. The malignant tumors are reportable regardless of origin, but non-malignant tumors that originate in the skull are not reportable.

• Chondroma (9220/0) is a benign tumor of cartilage cells. The ICD-O-3 Manual shows the code for bone in parentheses next to the morphology. Review the record carefully to determine if the tumor originated in bone or in an intracranial site. Because chondroma is a benign tumor, only complete an abstract if the primary tumor is in an intracranial site. A chondroma of the skull is not reportable.
• Chordoma is a malignant tumor arising from the embryonic notochord, and chondrosarcoma (9220/3) is a malignant tumor of cartilage cells. These tumor histologies are reportable, but you must determine if the primary site is bone or an intracranial site because the intracranial tumors are analyzed separately.

When ICD-O-3 was published, the code for pilocytic astrocytoma changed from malignant behavior (3) to borderline behavior (1). Registrars were instructed to continue to assign the code with malignant behavior. For data consistency, continue to assign the malignant behavior code (3) to pilocytic astrocytoma even after non-malignant CNS cases are collected.

Intracranial schwannoma (9560/0) is reportable for cases diagnosed January 1, 2004 and later. It is difficult to determine the intracranial site of a schwannoma. Assign the primary site for intracranial schwannoma to cranial nerves NOS (C72.5) when the site is not documented in the health record.