Microcore Skin Biopsies: A Novel, Micro-Invasive Skin Biopsy Technique Yielding Full-Thickness Histology.

backgroundPunch biopsies are considered the primary technique to obtain full-thickness skin specimens for dermatologic diagnoses. However, limitations include scarring, sampling error, poor margin identification, and post-sampling deformations.

objectivesTo introduce a novel micro-biopsy technique utilizing a modified hypodermic needle to achieve full-thickness skin micro-columns and a streamlined post-sampling process for histological analysis.

methodsEx-vivo skin biopsies were taken using a modified hypodermic needle and compared to 3 mm punch biopsies. They were fixed and processed inside the needle, resulting in a firm, columnar sample, which was then sectioned, stained, and imaged. Dimensions and horizontal shrinkage were also calculated.

resultsThe technique consistently yielded uniform, columnar-shaped histological samples. These sections were of sufficient quality to perform staining with a significantly smaller horizontal shrinkage rate compared to standard 3 mm punch biopsies.

conclusionsWe demonstrate a novel technique for a skin micro-biopsy that allows for fixation and processing of the tissue inside the sampling instrument, yielding small, full-thickness columnar skin histological samples that can be used for dermatological diagnosis with minimal post-sampling deformation. PLAIN LANGUAGE SUMMARY: Punch biopsies are considered the primary technique to obtain full-thickness skin specimens in order to diagnose skin conditions. However, scarring associated with skin biopsies and the deformations that happen to samples during processing pose persistent challenges. To minimize invasiveness, sub-millimeter skin punch biopsies have been introduced, but there has been no standardized, widely adoptable technique to utilize sub-millimeter skin punch biopsies to make diagnoses. Here, we introduce a novel skin biopsy needle that obtains skin samples that are less than 0.5 mm in diameter, which is below the scarring threshold, as well as a processing technique to easily fix, stain, and image the samples to make skin diagnoses.