MULTICENTRIC RECURRENT KERATOACANTHOMA AND VERRUCOUS CARCINOMA

Keratoacanthoma and verrucous carcinoma are low-grade squamous lesions that most often clinically present as difficult to heal verrucous formations. The similarity in the morphology of these pathological processes also creates difficulties in biopsy diagnosis, especially in incisional biopsies and fragmented material. We report a case of an 82-year-old man with multicentric recurrent malignant tumors of the skin. The patient was operated on twice in the surgical department of the Svilengrad Hospital. In 2022, a warty formation was removed from the capillicium, diagnosed biopsy as keratoacanthoma, and from the auricle, near the external auditory canal, an ulcerated area was removed, with a microscopic diagnosis of verrucous carcinoma. In 2025, a second operation was performed due to recurrence of the tumor processes in the same areas. The biopsy examination confirmed the diagnoses of the two primary tumors. An analysis and comparison of verrucous carcinoma and keratoacanthoma is performed. The similarities and differences between these two tumors, the reasons for the difficulties in morphological diagnosis, and a proposal for adding a new cytological criterion for their differentiation are discussed.