06 | PERIOCULAR “ULCUS RODENS-LIKE” SQUAMOUS CELL CARCINOMA TREATED WITH CEMIPLIMAB: A CASE REPORT

A. Zordan¹, M. Fino¹, N. Di Meo¹, I. Zalaudek¹, C. Defferrari², S. Sola³, C. Massone⁴ | ¹Department of Dermatology and Venereology, University of Trieste, Maggiore Hospital, Trieste, Italy; ²Department of Oncology, Galliera Hospital, Genoa, Italy; ³Department of Pathology, Galliera Hospital, Genoa, Italy; ⁴Department of Dermatology, Galliera Hospital, Genoa, Italy

Cutaneous squamous cell carcinoma (cSCC) is the second most common cutaneous malignancy of the periocular region after basal cell carcinoma (respectively, 10% and 90%). Periocular cSCCs show great clinical variability and currently only few cases of periocular ulcerated cutaneous SCC, mimicking ulcerated basal cell carcinoma ulcus rodens-type have been described. We hereby present the case of a 66-year-old woman with a 38x20 mm ulcerated lesion affecting the left medial canthus, the left nasal ala and the upper and lower left eyelids, that she stated to be present for at least 12 months before our first evaluation. Although initially asymptomatic, the patient complained about pruritus, a burning sensation and photophobia as the ulcer enlarged. The neoplasm was initially clinically diagnosed as an ulcus rodens basal cell carcinoma; however, histopathology and immunohistochemistry from incisional biopsy were diagnostic for an ulcerated and poorly keratinizing cSCC. A contrast-enhanced CT scan of the facial skeleton and neck was performed, highlighting tumoral extension to the extraconal adipose tissue and possible invasion of the left nasolacrimal duct, while excluding head and neck lymph node involvement. The patient refused a radical orbital exenteration surgery and radiotherapy was not feasible, hence treatment with endovenous cemiplimab for locally advanced SCC (lacSCC) was initiated. During the treatment a progressive shrinking of the lesion occurred, with a 10x5 mm residual lesion at the ninth month of follow-up, without concomitant adverse events. LacSCC, defined as cSSC not feasible of curative surgery or radiotherapy, can show different clinical presentations, and correct histopathological diagnosis is essential to establish the most adequate therapeutic approach for the patient. In the presented case, cemiplimab, an anti PD-1 monoclonal antibody approved as systemic treatment for lacSCC, allowed great therapeutic response and disease control in a challenging case of lacSCC presenting in a critical anatomic site and clinically simulating basal cell carcinoma.