Pediatric Mets

This input is used for staging

M Category

Notes

**Note 1:** Use code 70 when the only information is “distant metastasis, NOS,” and there is no documentation regarding the specific metastases. * If there are specific metastasis documented that are not listed in codes 15, 25, or 35, or 45, assign code 45 for “other specified distant metastasis.” **Note 2:** Code 00 for benign (behavior /0) and borderline (behavior /1) tumors. **Note 3:** The following adjacent sites, by direct or contiguous extension, are coded to 35. * Adjacent connective/soft tissue * Adjacent muscle * Bone * Circulating cells in cerebral spinal fluid (CSF) * Major blood vessel(s) * Meninges (e.g.; dura) * Multiple/multifocal tumors * Nerves (cranial, NOS) * Ventricular system **Note 4:** Leptomeningeal metastases, also known as carcinomatous meningitis and meningeal carcinomatosis, refers to the spread of malignant cells through the CSF space. These cells can originate from primary CNS tumors (e.g., in the form of drop metastases), as well as from distant tumors that have metastasized via hematogenous spread (code 35).

Default

NAACCR Item

NAACCR #1138

Code	Description
00	No visible disease on imaging (MRI brain and spine) beyond primary site of disease AND no tumor cells into the cerebrospinal fluid (CSF)
15	Tumor cells in the CSF * Circulating cells in cerebral spinal fluid (CSF)
25	Intracranial spread beyond a single lesion All sites * Bone (skull) (see code 45 for other bone involvement) * Major blood vessel(s) * Meninges (e.g., dura) * Multiple/multifocal tumors * Nerves (cranial, NOS) * Tumor invades or encroaches upon ventricular system Brain tumors (C700, C710-C719) * Anterior cranial fossa * Brain stem * Cerebellum * Cerebrum (cerebral hemisphere) * Contralateral hemisphere * Hypothalamus * Middle cranial fossa * Pallium * Posterior cranial fossa * Suprasellar brain * Tapetum * Thalamus CNS tumors (C701, C709, C720-C729) * Adjacent connective tissue * Adjacent muscle * Brain for cranial nerve tumor(s) * Sphenoid and frontal sinuses(skull) Pineal Gland (C753) * Adjacent connective/soft tissue * Cavernous sinus * Infratentorial and central brain
35	Visible metastasis in spine OR Visible metastasis in cervicomedullary (junction) Metastasis within CNS and CSF pathways * Carcinomatous meningitis * Drop metastasis * Leptomeningeal metastases * Meningeal carcinomatosis
45	Extra-neural metastasis All Sites * Blood * Bone (other than skull) (see code 25 for skull) * Bone marrow * Carcinomatosis * Distant lymph nodes, NOS * Further contiguous extension * Other specified metastasis Brain tumors (C700, C710-C719) * Nasal cavity * Nasopharynx * Other direct extension outside CNS * Posterior pharynx CNS tumors (C701, C709, C720-729) * Eye
70	Distant metastasis, NOS
99	Unknown; distant metastasis not stated Not documented in medical record Death Certificate Only

(1) Aitken JF, Youlden D, O’Neill L, Gupta S, Frazier AL, eds. Childhood cancer staging for population registries according to the Toronto Childhood Cancer Stage Guidelines – Version 2. Cancer Council Queensland and Cancer Australia: Brisbane, Australia; 2021.