Natural History of Keratoacanthoma: A Case of Spontaneous Regression in the Lower Eyelid

Introduction

Keratoacanthoma (KA) is a low-grade, very rapidly growing and typically self-limiting epithelial tumour arising from the infundibulum of hair follicles. It often presents as a dome-shaped nodule with a central keratin plug, typically on sun-exposed skin in elderly individuals.

Although histologically and clinically similar to squamous cell carcinoma (SCC), keratoacanthoma is usually benign and may regress spontaneously over weeks to months [1], [2], [3]. Risk factors include chronic UV exposure, trauma, chemical carcinogens (e.g. tar, tobacco), human papillomavirus (HPV) and immunosuppression.

The differentiation from SCC is critical, as misdiagnosis can lead to under- or overtreatment. Standard treatment is surgical excision, both for diagnostic certainty and complete removal.

Publikationsverlauf

Eingereicht: 02. November 2025

Angenommen: 14. Januar 2026

Artikel online veröffentlicht:
17. Februar 2026

• References

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• 6 Markowitz O, Utz S. Differentiating Early Stage Cystic Keratoacanthoma, Nodular Basal Cell Carcinoma, and Excoriated Acne Vulgaris by Clinical Exam, Dermoscopy, and Optical Coherence Tomography: A Report of 3 Cases. J Clin Aesthet Dermatol 2015; 8: 48-50