Abstract
Histological analysis was conducted on 90 patients with different clinical
presentations of actinic keratosis (AK). The most prevalent forms were hypertrophic (45
cases) and bowenoid (20 cases) AK. The acantholic form of AK was observed least frequently
(2 cases). The results of the study indicated that the most common histological changes in
AK involved the epidermis, which could be considered pathognomonic for AK. These
changes included dysplasia of epidermal cells, presence of atypical keratinocytes in the
basal and spinous layers, abnormal mitotic activity, and disruption of keratinocyte
stratification. On the other hand, phenomena such as acanthosis, hypergranulosis, and
epidermal atrophy were considered reactive rather than specific to AK.