Giant Keratoacanthoma over Unilateral Leg Secondary to Chronic Friction and Successfully Treated with Wide Local Excision and Flap: A Rare Case Report

Keratoacanthomas (KAs) are fast-growing cutaneous tumours mostly over sun-exposed areas. Lesions with size larger than 20-30 mm are termed as giant KA. Giant KA is very rare and sometimes develops over trauma, surgical site and pre-existing dermatosis such as lichen planus hypertrophicus and prurigo nodularis. Giant KA may mimic squamous cell carcinoma (SCC) causing anxiety among patients and rarely develop into SCC, requiring prompt treatment. Here, we report a rare case of giant KA over the right leg, developing due to chronic friction. Histopathology proved to be KA without malignant changes. He was treated with wide local excision and flap reconstruction. Our case highlights how even chronic friction leads to microtrauma, which may result in the development of a giant-sized premalignant tumour like KA. Timely intervention like biopsy will help dermatologists to diagnose and manage successfully. Our case also adds to the pool of KAs treated by wide local surgical excision with flap reconstruction.