Naval Hospital Jacksonville Family Medicine Residency Jacksonville, Florida
Introduction: Keratocanthomas (KA) are fast growing skin lesions, commonly misconstrued as cancerous. Improved screening measures and education are needed to identify KA’s.
Case Study: 57 year old male with a history of basal cell skin cancer and chronic pain presented with concerning new skin lesion on his neck. The patient stated the lesion appeared on the right side of his neck 2 weeks prior and had tripled in size. He denied any bleeding from the lesion, but noted nerve-like pain. Patient had significant sun exposure history.
Exam showed a 4mm dome-shaped nodule posterior to the right sternocleidomastoid with central keratosis, erythema, and telangiectasias. A shave biopsy was performed and confirmed Keratocanthoma. Care was continued with Dermatology and Mohs surgery.
Discussion: KA is a fast growing skin lesion found in fair-skinned older males. It is a fast growing keratin-filled follicular infundibula that is more common on UV exposed skin that will regress over time. Due to its histological and clinical overlap with Squamous Cell Carcinoma (SCC), KA is commonly overdiagnosed as SCC.
As seen in our case, KA is a fast progressing lesion that has three stages: proliferations, stabilization, and regression. Distinction from SCC is key in diagnosing KA and most commonly done at the histological examination. KA cannot be differentiated based on a dermoscopy exam alone. KA’s histological features include symmetry, keratin-filled centers, and a sharp demarcation between tumor and stroma. It is important to note that no single feature can differentiate KA from SCC, but with all the histological features noted the diagnosis can be made.
Improving our understanding of clinical presentation and pathology of KA will reduce over treatment and improve patient outcomes.
