Recognition and Discrimination of Tissue-Marking Dye Color by Surgical Pathologists Recommendations to Avoid Errors in Margin Assessment

Objectives: A variety of tissue-marking dye (TMD) colors can be used to indicate surgical pathology specimen margins; however, the ability of pathologists to differentiate between specific microscopic margin colors has not been assessed systematically. This study aimed to evaluate pathologists' accuracy in identifying TMD color and determine the least ambiguous combinations of colors for use in surgical pathology. Methods: Seven colors of TMD were obtained from three manufacturers and applied to excess formalin-fixed uterine tissue. Study blocks contained multiple tissue pieces, each marked with a different color from the same manufacturer Slides were assessed by eight participants for color and color distinctness of each piece of tissue. Results: Black, green, red, and blue TMDs were accurately identified by most participants, but participants had difficulty identifying violet, orange, and yellow TMDs. Black, green, and blue TMDs were most commonly rated as confidently discernable. Conclusions: Pathologists have difficulty identifying and distinguishing certain colors of TMDs. The combined use of certain colors of TMDs (yellow/orange/red, blue/violet, and red/violet) within the same specimen should be avoided to decrease the risk of inaccurately reporting specimen margins.