Patient and Tumour Characteristics of Keratoacanthoma in a Large, Community-based Cohort Study from Queensland, Australia.

Keratoacanthomas are common keratinocyte skin tumours. However, there is little community-based data published on the clinical features of keratoacanthoma. The aim of this study was to describe the patient and tumour characteristics of keratoacanthomas, as well as their treatment patterns. Data were obtained from the QSkin Sun and Health study, a prospective cohort of 40,438 randomly sampled and consented participants aged 40-69 years in Queensland, Australia. In 2010, a baseline survey collected data, including demography, phenotype, ultraviolet radiation exposure, medical history and lifestyle. Histopathological reports of keratoacanthomas arising until 30 June 2014 were reviewed. In total, 584 participants developed 738 keratoacanthomas; 18% of participants developed multiple tumours. Common patient characteristics were male sex (58%), age ≥60 years (76%), fair skin (80%), and previous history of actinic keratoses/keratinocyte cancers (89%). Keratoacanthomas were commonly located on the legs/feet (48%), and rarely on the the head/neck (7%). Excision was the most frequently used surgical method (71%) Evidence of histopathological regression was reported in 67% of keratoacanthomas, suggesting a potential for spontan-eous resolution in a significant proportion of keratoacanthomas.