DS04 Improving Mohs micrographic surgery mapping with handheld thermal print instant photography

Abstract

Mohs micrographic surgery (MMS) is based on the principle of complete tumour excision with real-time histological margin assessment. Accurate Mohs mapping is a critical step, allowing correlation between excised tissue and its anatomical location to guide subsequent stages and reconstruction. Traditional mapping methods, including freehand drawings and standardized anatomical templates, are limited by variability in drawing ability and poor representation of patients with nonstandard anatomy. These limitations are amplified in complex cases, including large irregular defects and full-thickness defects. Our aim was to describe and evaluate a low-cost, rapid and reproducible method of Mohs tissue mapping using instant thermal print photography. A handheld thermal print instant camera was used to obtain point-and-shoot photographs of lesions prior to excision. Greyscale printouts served as the Mohs maps. Tissue outlines were drawn directly onto the prints using permanent marker pens, with orientation nicks clearly identified. Positive margins were marked in red ink. For subsequent stages, the same image was reprinted from the camera’s internal memory and updated to reflect additional tissue layers. All stored images were deleted at the end of the surgical list to preserve patient confidentiality. Thermal printing of digital imaging allowed rapid, anatomically accurate depiction of surgical defects and excised specimens. Dependence on freehand illustration and predesigned templates was reduced, resulting in more consistent mapping and fewer transcription errors. The greyscale format supported intraoperative patient discussions, particularly for individuals who were anxious or preferred not to view realistic wound images. Printouts were scanned clearly into electronic patient records and formed part of the intraoperative documentation. Limitations included the need for device charging and paper replenishment, and initial suboptimal image density (mitigated through setting adjustments). A handheld camera with an integrated thermal printer represents a practical and reproducible alternative for Mohs mapping, particularly in complex cases. It is inexpensive and integrates easily into clinical workflows.