Histologic Subtype
Description
Histology code for appendiceal tumors (8480) is defined as “Mucinous Adenocarcinoma (in situ or invasive).” In addition, there are also low-grade appendiceal mucinous neoplasm (LAMN) and high-grade appendiceal mucinous neoplasm (HAMN) diagnoses that are assigned the same histology.Notes
**Note 1:** **Effective years** * This SSDI is effective for diagnosis years 2023+ * For cases diagnosed 2018-2022, this SSDI must be blank **Note 2:** **Determining histology** * Use the **Solid Tumor Rules** to determine histology prior to coding this SSDI. * Histology 8480/2 or 8480/3 have multiple definitions that are collected in this histology. * This data item is used to further identify specific subtypes for histology code 8480/2 or 8480/3.| Code | Description |
|---|---|
| 0 | Histology is NOT 8480 |
| 1 | Low-grade appendiceal mucinous neoplasm LAMN |
| 2 | High-grade appendiceal mucinous neoplasm HAMN |
| 3 | Mucinous Adenocarcinoma/carcinoma Mucus Adenocarcinoma/carcinoma Mucoid adenocarcinoma/carcinoma Colloid adenocarcinoma/carcinoma |
| 4 | Other terminology coded to 8480 |
| <BLANK> | NA-Diagnosis year is prior to 2023 |