LAUSR

Dear Editor Sebaceous carcinoma (SC) is a rare, slow-growing, but aggressive skin tumor first described by Allaire in 1891. Although its etiopathogenesis remains poorly understood, it originates from the sebaceous glands and may be related to genetic factors, ultraviolet radiation exposure, and immunosuppression. It is mostly located in the eyelids, and extraocular SC is exceedingly uncommon. A 72-year-old male, liver transplant recipient since 2012 and under immunosuppression with tacrolimus, was observed with a 30 × 30 mm erythematous eroded, friable, vegetative tumor on the left nasal ala (Figure 2A), which was growing slowly for the past 2 years. No cervical palpable lymph nodes were noticed. Multiple biopsies were previously performed, all inconclusive. A new biopsy led again to nonspecific findings, showing a pseudocarcinomatous hyperplasia of the epidermis with an underlying dense mixed inflammatory infiltrate, as well as some focal and mild cytological atypia. Due to evolution of the lesion and clinical suspicion of a cutaneous malignant neoplasia, surgical excision (lateral margin of 6 mm) under locoregional anesthesia (infraorbital nerve block) was decided, resulting in a full-thickness defect of the entire left nasal ala (Figure 2B). A delayed surgical reconstruction of this defect was decided, at the time when histological evaluation allowed an accurate diagnosis and ensured negative surgical margins. Histology showed typical findings of SC based on a proliferation of relatively uniform sebaceous differentiated peripheral basaloid cells, organized in lobes and with high mitotic activity (Figure 1). Surgical margins were tumor free, and the reconstruction (4 weeks after excision) was performed under general anesthesia. The inner nasal lining was partially obtained using a septal mucosal flap (Figure 2C). The semirigid support of the nasal ala was obtained by apposition of chondral graft also harvested from the nasal septum (Figure 2D). The skin defect was covered with a paramedian frontal flap. The tip of the flap was folded over to repair the alar contour and the remaining portion of the inner lining (Figure 2E). In a second stage, 3 weeks later, the flap pedicle was divided (Figure 2F). A third stage (6 weeks later) was required for flap refinement, with a good functional and aesthetic result in the follow-up visit 3 months later (Figure 2G). This case of an SC of the nasal ala in an immunosuppressed patient highlights two main aspects: on the one hand, the rarity and difficulty of the diagnosis, particularly due to its extraperiorbital location; on the other hand, the challenge of reconstruction of nasal unit defects, both for its functional and aesthetic relevance. Moreover, we would like to emphasize the importance of waiting for the histological confirmation of free surgical margins in the suspicion of a tumor not yet characterized and not excised by a microscopically controlled method. In fact, the immediate reconstruction of the surgical defect caused by the treatment of this type of tumors is generally risky due