Özet:

Objective: Mutations in genes encoding proteins along the RAS-RAF-MEK-ERK pathway have been detected in a variety of tumor entities, including malignant melanoma, thyroid, colon, over carcinomas and some sarcomas. The increased activity of BRAF V600E leads to downward signalization activation via mitogen-activated protein kinase (MAPK), which plays an important role as cell growth, differentiation and survival regulator. Latest data show BRAF undergoes mutation in nearly 7% of cancers and this situation makes BRAF another important oncogene in this pathway. We aimed to evaluate the relationship between keratacanthoma and BRAF expression. Methods: 28 cases of keratocanthomas were included in this study. Sections were taken from the selected blocks with a thickness of 3 microns with poly-lysine coating. BRAF antibody was applied to the tissues. The obtained preparations were evaluated by light microscopy. It was rated according to the degree of staining in epidermis. Results: Areas showing cytoplasmic staining with BRAF were evaluated in sections. It was observed that there was no staining in the keratocanthomas, and staining in sebaceous glands and sweat glands in peripheral basal cells. It was also noted that the sweat glands had more stain than the sebaceous glands. The cases included 18 males and 10 females with ages varying from 33 to 85 years. The duration of the lesions was between one month and one year. Lesion dimensions varied from 5 to 70 mm, with mean size of 21 mm. There were 14 cases (50%) with head and neck localization, and 14 cases (50%) with localization other than the head and neck. Conclusion: As a result, it has been concluded that BRAF mutation may not be involved in keratoacanthoma.

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