It is important to include that the lesion is associated with another cancer. A biopsy will establish the diagnosis. Punch biopsies are not effective in differentially diagnosing for EMPD and as a result, excisional biopsies of the affected area are taken . A positive test result for EMPD shows increased numbers of large polygonal cells with a pale bluish cytoplasm, large nucleus and nucleolus, infiltrating the epidermal layer. These neoplastic cells can be found singly scattered or can appear in groups called nests.