P145 Sebaceous carcinoma management guidelines

Abstract Sebaceous carcinoma (SC) is a rare adnexal tumour arising from sebaceous glands. It is generally categorized as ocular or extraocular tumours, which have potential to metastasize. SC can present sporadically or as part of Muir–Torre syndrome. Diagnosis of ocular SC may be delayed due to its appearance mimicking benign eyelid disorders. The worldwide incidence for SC is estimated at 0.1–0.2 per 100 000, whereas in the UK it is approximately 0.23 per 100 000, with 80% of cases occurring in the head and neck region. SC can metastasize to lymph nodes in around 8–15% of cases, and metastases to distant organs such as the liver, lung and bone have also been reported. Diagnosis of SC is based on histopathological evidence from biopsy with the aid of immunohistostaining. There is no current national guidance for management of SC. The aim of this review is to present the best available evidence to help formulate a management pathway for patients with SC. A literature search was carried out, with 57 relevant articles reviewed. Staging investigations in ocular SC can include optical coherence tomography and conjunctival map biopsies, where there is pagetoid or diffuse conjunctival spread. Margin-controlled surgery using Mohs surgery or complete circumferential peripheral and deep margin assessment is recommended as a first-line treatment in SC. These approaches have been proven to reduce local recurrence and improve overall survival. Radiotherapy can be considered if surgery is contraindicated, and as adjuvant therapy in locally advanced primary tumours. The evidence about other treatment options such as chemotherapy, immunotherapy, targeted therapies, cryotherapy and mitomycin is sparse, and can be assessed on an individual-case basis with multidisciplinary team involvement. Prognosis is dependent on complete excision of SC with margin-controlled surgery. The follow-up recommendation is every 6 months for 3 years, then annually with examination of the entire skin and lymph nodes, with consideration for genetic testing if the criteria for Muir–Torre syndrome are met.