Supplementary Material for: Regression of Periocular Basal Cell Carcinoma: A Report of Four Cases with Clinicopathologic Correlation

<b><i>Objectives:</i></b> To describe the spectrum of clinical and histopathological features of a case series of basal cell carcinoma (BCC) with spontaneous regression and to discuss this phenomenon. <b><i>Method:</i></b> Four cases of BCC with complete/substantial regression were retrospectively identified. Patients’ records were analyzed for demographic data, clinical appearance, and the postoperative course. Formalin-fixed, paraffin-embedded specimens were routinely processed and stained with hematoxylin and eosin and periodic acid Schiff. <b><i>Results:</i></b> Complete (<i>n</i> = 1) or partial (<i>n</i> = 3) regression of BCC was observed in 4 patients. Two lesions at the medial canthus were histologically diagnosed as nodular BCC with significant regression. One lesion at the lower eyelid exhibited a complete regression which did not require surgical intervention. The other lesion at the lower eyelid presenting with ulceration and madarosis was excised. Scar tissue without evidence for a neoplasm was present histologically. Subsequently, the patient developed a recurrence with a histologically proven micronodular BCC. <b><i>Conclusions:</i></b> BCC can show spontaneous substantial or complete regression. Histological tumor absence in lesions which are clinically suspicious for a neoplasm can be a hint for a regressive BCC. Recurrences may develop from remaining tumor islands warranting periodical clinical visits in cases of clinically as well as histologically suspected regressive BCC.