04-12-2024 LAMN Histology and Behavior
Match the Scenario with the correct Answer:
Answer: Histology/Behavior Code: 8480/3
- 2021 Appendectomy: LAMN diffusely involving the appendix and perforating the visceral peritoneum, as extensive intraperitoneal mets. 2023 Lung wedge resection: metastatic mucinous neoplasm involving lung parenchyma and pleura, consistent with metastasis of the known appendiceal primary
- 2023 Patient who presented with right lower quadrant pain and a CT scan confirming appendicitis, no lymph node or metastatic disease seen. Laparoscopic appendectomy: 2cm Low-grade appendiceal mucinous neoplasm. Tumor invades through muscularis propria into subserosa or mesoappendix but does not extend to serosal surface. No Regional lymph nodes removed. pT3
- 2023 Patient who presented with right lower quadrant pain and a CT scan confirming appendicitis, no lymph node or metastatic disease seen. Laparoscopic appendectomy: 2cm Low-grade appendiceal mucinous neoplasm confined to the muscularis propria. No Regional lymph nodes removed. pTis(LAMN)
Scenario B matches the Answer 8480/3 See discussion below:
- This case would not be reportable. LAMN is reportable starting with cases diagnosed in 2022. Pre-2022 LAMN is not reportable even when treated with surgery and chemotherapy. [SEER Sinq 20230007]
- This case is reportable. Histology would be 8480/3 per Colon Solid Tumor Rules/AJCC v9 pT3 pNx cM0 Stage 99
- Rule H6 Code invasive mucinous adenocarcinoma 8480 when the diagnosis is any of the following:
- The pathologist has staged the LAMN as T3 or T4
- This case is reportable. Histology would be 8480/2 per Colon Solid Tumor Rules / AJCC v9 pTis (LAMN) cN0 cM0 Stage 0
- STR Rule H5 Code low grade appendiceal mucinous neoplasm (LAMN) and high grade appendiceal mucinous neoplasm (HAMN) 8480/2 when:
- Diagnosis date is 1/1/2022 forward AND
- Behavior is stated to be in situ/non-invasive OR
- Behavior is not indicated
Tip:
Watch the NAACCR Webinars Lower GI Part 1 & 2 presented 06-2023.
*Omega Staff this is available on the Cancer Registry Education SharePoint site
*If not on Omega staff, please check with your State Registry to see if these Webinars might be available for viewing