Fig. (2) Clinical course and histopathological features of case 2. (a) NUM with a nodule on the hyponychium on the left great toe. (b) Wide skin excision extending vertically to the subperiosteal layer, with minimized amputation of the neighboring bone. (c) Placement of INTEGRA® directly onto the surgical defect. (d) Presentation of atypical melanocytes scattered along the basement membrane of the nail matrix with nodular invasion at the hyponychium. (e) INTEGRA® developed the regenerated dermal tissue entirely covering the defect within one month after the first phase operation. (f) Reconstruction with PSVNSG using a graft harvested from the patient’s abdominal skin. (g) Postoperative outcome six months after the skin grafting