Variable Tissue Inking for Staged Excision (“Slow Mohs”) Safety: A Protocol for Permanent Section Control

Background Whenever multiple specimens are sent to a pathology lab for processing and interpretation, there are multiple potential points of error in the entire process. Every dermatologist has likely experienced receiving a pathology report in which, at some point, the specimens were misidentified. Mohs and “Slow Mohs” (Staged excision with permanent section margin control) offer precise tumor removal and a tissue‐sparing approach, but often require interpretation of several specimens from the same patient. Meticulous attention to mapping is absolutely necessary to maintain exact specimen orientation and identification. Sending specimens out for permanent section processing introduces more potential points in handling for error in specimen tracking and orientation, from mislabeling of bottles to mishandling or mix‐up of specimens once received by the processing lab. We present a variable tissue‐marking protocol to enhance patient safety and specimen identification, significantly reducing any potential for mapping or orientation error. Methods In our protocol, the surgeon intentionally alters the ink color combination for every section submitted. The surgeon inks the specimens immediately in the clinic room to maintain precise orientation and records these unique patterns in the patient's record and Mohs map. For example, if a Mohs‐type layer is sectioned into quadrants, the 12 o'clock cut is inked one color, the 3 o'clock another, and so forth. This results in four uniquely identifiable specimens that can no longer be misidentified or misoriented, eliminating a potential for error between practices. In our practice, for example, the inking is as follows: 12 o'clock blue, 3 o'clock green, 6 o'clock black, and 9 o'clock red. The first quadrant, 12–3 o'clock, is the only specimen with blue and green; the second quadrant, 3–6 o'clock, is the only quadrant inked green and black, and so forth. The specimens could all be mixed up or mislabeled, and the pathologist would still be able to interpret the mapping accurately. This ensures that each quadrant is accurately identified and mapped. Results This variable marking serves as a secondary unique identifier that provides a safety stop‐check for slide interpretation. By assigning distinct color sets to each specimen, the potential for mapping errors or patient‐specimen mismatches is essentially eliminated. Conclusion Utilization of unique color coding significantly enhances laboratory accuracy and patient safety. This simple protocol ensures the correct interpretation is accurately mapped to the correct location in staged excision specimen processing.