DS24 Is surgery the best management for keratoacanthoma centrifugum marginatum?
Authors: Surgenor Laura , Austin Sinead , Dolan Olivia , Lannon Declan , Ashraf Sana , Goh Alicia 
Published: June 2024

Abstract
Keratoacanthoma centrifugum marginatum (KCM) is a rare variant of keratoacanthoma (KA). KCM typically presents as large solitary tumours with raised, rolled borders with distinctive patterns of continual peripheral tumour growth and central atrophic scarring. Although the clinical features are distinguishable from typical KA, KCM poses a diagnostic challenge due to its rarity, and lack of characteristic histopathological features. Classically, surgical intervention is the preferred treatment option; however, when tumours involve important anatomical structures we pose the question: Is surgery the best management approach? A 28-year-old woman presented with an 8-week history of a rapidly evolving tumour involving the right nasal sidewall. Initially measuring 2.6 × 2.5 cm, it progressively increased in size, extending intranasally with fullness of the right nasal septum. As the lesion was too large to entirely excise, it was debulked by shave excision. The clinical and pathological findings were compatible with KCM. Further surgical intervention to clear the deep margin was not feasible due to risk of significant functional impairment and disfigurement. Numerous other treatment options for KCM have been reported, including oral retinoids. Following review of the literature it was our intention to commence low-dose isotretinoin, but the patient declined as she had plans to conceive. However, reassuringly, with close follow-up and serial photographs there has been evidence of further involution. KCM was first described as a unique subtype of KA by Miedzinski and Kozakiewicz in 1962 {Miedzinski F, Kozakiewicz J. [Keratoacanthoma centrifugum – a special variety of keratoacanthoma]. Hautarzt 1962; 13: 348–52; in German}. While tumour involution is a typical feature of KA, in contrast, KCM rarely involutes and can display a protracted long-term growth pattern, leading to significant tissue destruction and disfigurement. Therefore, active intervention is preferred. KCM is best regarded as a benign entity. It has been associated with local recurrence; however, no reported cases of metastatic KCM exist to date. Despite this, KCM is still regarded by some within the spectrum of well-differentiated squamous cell carcinoma. The management dilemma triggered by this case poses an opportunity to consider the importance that retinoids play in the context of keratinocyte-based tumours. Retinoids are known to inhibit early stages of carcinogenesis via DNA damage. Retinoic acid is a potent antioxidant against tumour development, and can induce apoptosis via creation of reactive oxygen species in cancerous cells. Oral retinoids are well recognized as effective chemoprophylaxis against the formation of keratinocyte tumours in organ transplant patients. We present this case to highlight a rare entity in a young person. There is a lack of consensus regarding the use of retinoids in KCM due to the paucity of cases; however, they do merit consideration in selected cases.