Microvascular Density (MVD), a quantitative measure of tumor vascularity, is a prognostic factor for uveal melanoma.

Microvascular Density (MVD), is a Registry Data Collection Variable in AJCC. This data item was previously collected as Uveal Melanoma, CS SSF# 13.

Item #	Length	Source of Standard	Year Implemented	Version Implemented	Year Retired	Version Retired
3891	2	NAACCR	2018	18

00	No vessels involved
01-99	01-99 vessels per 0.3 square millimeter (mm2)
X1	Greater than or equal to 100 vessels per 0.3 square millimeter (mm2)
X2	Lowest quartile for laboratory
X3	Second quartile for laboratory
X4	Third quartile for laboratory
X5	Highest quartile for laboratory
X7	Test ordered, results not in chart
X8	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.)
X9	Not documented in medical record Microvascular Density (MVD) not assessed or unknown if assessed

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.