Data Last Updated: June 9, 2025

High Risk Histologic Features

Description

High Risk Histologic Features are defined in AJCC 8 Chapter 15 to include the terms “poor differentiation, desmoplasia, sarcomatoid differentiation, undifferentiated.” High risk histologic features are a prognostic factor for cutaneous cell carcinomas of the head and neck. In addition to the tumor size (diameter, not depth), the presence of certain specific high-risk features is of prognostic significance for skin cancers of the head and neck.

Notes

**Note 1:** **Physician Statement** * Physician statement of high-risk histologic features can be used to code this data item when no other information is available. **Note 2:** **High risk histologic features include** * Desmoplasia * Poor differentiation (grade 3) * Sarcomatoid differentiation (features) * Undifferentiated (grade 4)
Code Description
0 No high risk histologic features
Non-invasive neoplasm (behavior /2)
1 Desmoplasia
2 Poor differentiation (grade 3)
3 Sarcomatoid differentiation
4 Undifferentiated (grade 4)
5 Multiple high risk histologic features
6 Histologic features, NOS (type of high risk histologic feature not specified)
8 Not applicable: Information not collected for this case
(If this information is required by your standard setter, use of code 8 may result in an edit error)
9 Not documented in medical record
High risk histologic features not assessed or unknown if assessed