The elastic properties of cancerous skin: Poisson's ratio and Young's modulus

Background: The physical properties of cancerous skin tissue have rarely been measured in either fresh or frozen skin specimens. Of interest are the elastic properties associated with the skin's ability to deform, i.e., to stretch and compress. Two constants - Young's modulus and Poisson's ratio - represent the basic elastic behavior pattern of any elastic material, including skin. The former relates the applied stress on a specimen to its deformation via Hooke's law, while the latter is the ratio between the axial and lateral strains. Objectives: To investigate the elastic properties of cancerous skin tissue. For this purpose 23 consecutive cancerous tissue specimens prepared during Mohs micrographic surgery were analyzed. Methods: From these specimens we calculated the change in radial length (defined as the radial strain) and the change in tissue thickness (defined as axial strain). Results: Based on the above two strains we determined a Poisson ratio of 0.43 +/- 0.12 and an average Young modulus of 52 KPa. Conclusions: Defining the elastic properties of cancerous skin may become the first step in turning elasticity into a clinical tool. Correlating these constants with the histopathologic features of a cancerous tissue can contribute an additional non-invasive, in vivo and in vitro diagnostic tool.