L. G. Gutwein1, B. Davignon3, T. M. Katona2, C. L. Wade2, R. Sood1, S. S. Tholpady1 1Indiana University School Of Medicine,Plastic & Reconstructive Surgery,Indianapolis, IN, USA 2Indiana University School Of Medicine,Pathology & Laboratory Medicine,Indianapolis, IN, USA 3Rose Hulman Ventures,Terre Haute, IN, USA
Introduction: More diagnoses of skin cancer occur than all other cancers combined. The most common method to biopsy a skin lesion is the shave biopsy (SB). Shave biopsies are efficient and require no stitch therefore the preferred method to sample a lesion. However, SB application requires proficient technique primarily utilized by dermatologists. Additionally, the SB depth is subjective and uncertain at time of harvest. Malignant melanoma depth of invasion (Breslow depth) is the primary determinate of prognosis and guides clinical management of this disease. The decision point is 1mm depth of invasion measured from the stratum granulosum to determine the need for SLN biopsy and 1 vs. 2cm margin of excision. The present study examines an innovative SB design that is user friendly and quantifies the depth of specimen harvest at the time tissue acquisition.
Methods: A depth quantified SB prototype was constructed on a 3-D printer from DurusWhite, a polypropylene material, and fitted with custom fabricated scalpel blade. The depth of biopsy from the stratum corneum (surface of skin) was engineered to be at least 1.1mm. Fresh cadeveric abdominal tissue SB samples were harvested and placed immediately in formalin after the depth margin was inked. Hematoxylin and eosin staining was performed with microscopic analysis to determine depth harvest consistency.
Results: Five tissue samples were harvested and analyzed with light microscopy with the following depths from the stratum granulosom (greatest Breslow depths): 1.32, 1.48, 1.05, 1.42, and 1.10mm. The average depth of specimen harvest was 1.27 mm (standard deviation 0.19mm). The average specimen width where the depth was of at least 1.1 mm was 1.5mm (standard deviation 0.56mm). No specimen harvest violated the entire thickness of dermis indicating a safe device that leaves a wound to heal via secondary intention (as is standard in conventional shave biopsy).
Conclusion: Our innovative SB prototype proved consistent specimen harvest beyond 1mm from the stratum granulosum as required for accurate biopsy interrogation of malignant melanoma. Future studies will prove increased ease of use with direct controlled comparison to the conventional shave biopsy design. Implementation by primary care doctors and midlevel providers is the ultimate goal in order to decrease waiting time to lesion biopsy and reduce overall healthcare cost, as many lesions biopsied are ultimately benign.