A Case of Non-pigmented Basal Cell Carcinoma Involving a Wide Subclinical Extension

Abstract

Pigmented basal cell carcinoma (BCC) is more common in Asians than in Caucasians. In Asian patients, the boundaries of BCC are clear due to the presence of pigmentation, and the recurrence rate after conventional wide resection is low. However, determining the appropriate surgical margins for non-pigmented BCC is difficult, even with dermoscopy. In addition, subclinical extension of BCC may complicate the case further and require several rounds of Mohs surgery. Here, we report a case of a 39-year-old female patient, who was diagnosed initially with Pigmented BCC typical for Asians7 and underwent a resection. However, an area of extensive non-pigmented subclinical extension was found later, which required four additional rounds of resection. During the initial dermoscopic examination and first surgical resection in this patient, arborizing blood vessels were found around the ulcers and pigmented sites; however, there were no indications of any other widespread nonpigmented lesions. The following characteristics have been reported previously for patients getting subclinical extension: 1) being an elderly male; 2) Fitzpatrick skin type I; and 3) a history of BCC. As our patient did not have any of these characteristics, this case was considered to be unusual. After four rounds of excision, we could completely remove widespread non-pigmented lesions.