Data Last Updated: June 9, 2025

NAACCR Item #3887: Measured Basal Diameter

Item # Length Source of Standard Section Name Year Implemented Version Implemented XML NAACCR ID Parent XML Element
3887 4 NAACCR Stage/Prognostic Factors 2018 18 measuredBasalDiameter Tumor
Required Status:

NPCR Collect: No recommendation
CoC Collect: Required, site specific
SEER Collect: Required, site specific
CCCR Collect: No recommendation

Description
Measured Basal Diameter, the largest basal diameter of a uveal melanoma, is a prognostic indicator for this tumor.
Rationale
Measured Basal Diameter is listed as a Registry Data Collection Variable in AJCC. It was previously collected as Uveal Melanoma, CS SSF# 2.
Allowable Values
0.0-99.9, XX.0, XX.1, XX.2, XX.3, XX.4, XX.5, XX.6, XX.8, XX.9
Codes
Code Description
0.0 No mass/tumor found
0.1-99.9 0.1-99.9 millimeters (mm) (Exact measurement to nearest tenth of mm)
XX.0 100 millimeters (mm) or larger
XX.1 Described as "less than 3 mm"
XX.2 Described as "at least" 3 mm
XX.3 Described as "at least" 6 mm
XX.4 Described as "at least" 9 mm
XX.5 Described as "at least" 12 mm
XX.6 Described as "at least" 15 mm
XX.8 Not applicable: Information not collected for this case (If this information is required by your standard setter, use of code XX.8 may result in an edit error.)
XX.9 Not documented in medical record Cannot be determined by pathologist Measured Basal Diameter not assessed or unknown if assessed
Code Notes
Each Site-Specific Data Item (SSDI) applies only to selected primary sites, histologies, and years of diagnosis. Depending on applicability and standard-setter requirements, SSDIs may be left blank.