Pathologic M

This input is used for staging

Notes

**Note 1:** Liver metastasis implies the presence of tumor inside the liver parenchyma as one or more nodules. * Do not code as liver metastasis when there is adherence to the liver capsule, even if extensive. For liver adherence, see T (primary tumor) **Note 2:** When a patient has more than one area of gastrointestinal stromal tumor (GIST), it is important to try to distinguish between intra-abdominal metastasis and tumor multiplicity. Distant metastases are relatively rare in GISTs, but they are increasingly detected with sophisticated radiological studies. Intra-abdominal metastasis will present as tumor involvement in the abdominal cavity outside the main tumor mass, in the peritoneum, omentum, serosae of organs, and the cul-de-sac, among other areas. * Assign this form of metastasis as cM1 **Note 3:** Tumor multiplicity, in contrast, will present with anatomically separate, multiple tumors of different sizes arising independently in the GI tract. This form of tumor multiplicity usually will be seen in patients with neurofibromatosis type 1 or familial GIST syndrome, but in rare instances may be seen in patients without these conditions. This form of multiplicity should not be coded as metastasis, but the presence of multiple tumors should be coded in **Site-Specific Factor 15, Tumor Multiplicity**. * When a solitary omental or mesenteric tumor mass is found with a primary GIST elsewhere, do not code this as a metastasis. Code it as multiple tumors in **Site-Specific Factor 15, Tumor Multiplicity** * When multiple tumor areas are present and it is not stated whether these are metastases or independent tumors, consult with a physician if possible to determine how to code them. If a decision cannot be made, assign cM0 **Note 4:** Peritoneal nodules are not excluded as a staging component for M1 disease of GISTColon and may be assigned M1. **Distant lymph nodes** **All subsites** Common iliac External iliac Para-aortic Retroperitoneal Superior mesenteric Distant lymph nodes, NOS **Cecum (C180), Ascending colon (C182), Hepatic Flexure (C183), Transverse colon (C184)** Inferior mesenteric

NAACCR Item

NAACCR #900

Pathologic M	Pathologic M Display	Description	Registrar Notes
c0	cM0	No distant metastasis	Unknown; distant metastasis not stated Distant metastasis cannot be assessed Not documented in patient record
c1	cM1	Distant metastasis	CLINICAL assessment only: Distant lymph nodes, NOS Distant metastasis, NOS Carcinomatosis Distant metastasis WITH or WITHOUT distant lymph node(s) Distant metastasis, NOS Stated as M1
p1	pM1	Distant metastasis	HISTOLOGICALLY confirmed: Distant lymph nodes, NOS Distant metastasis, NOS Carcinomatosis Distant metastasis WITH or WITHOUT distant lymph node(s) Distant metastasis, NOS
88	88	Not applicable	In situ case but no pTis is defined by TNM Death certificate only (DCO) case
<BLANK>	BLANK	See Registrar Notes	Pathologic classification criteria not met No pathologic workup for T and N categories and no pathologic evidence of metastasis Only Pathologic Stage Group documented (no T, N, or M information available)