68-year-old female exhibits an exulcerated tumor with a tendency to bleed on her left cheek.
- The central part of the skin exhibits a circumscribed tumor growing in a nodular pattern. The tumor deeply infiltrates the dermis. Above of the tumor, the epidermis shows flattened rete ridges. Exulceration is not observed on the section shown.
- The tumor consists of nodules and in the periphery cords of tumor cells. Nodules exhibit distinct peripheral palisading of cells, in the center formation of whirls is observed. Morphologically, the tumor cells correspond to the basal cells of the epidermis.
- At the dermo-epidermal junction presence of nests of atypical basaloid cells. In one location, an artefactual cleft is seen between part of the basaloid cells and the dermis. These retraction spaces between tumor cells and dermis are a characteristic feature of basal cell carcinomas.
- The dermis surrounding the tumor shows an inflammatory infiltrate consisting mostly of lymphocytes.
Biological behavior: Basal cell carcinomas grow locally invasive and destructive. They exhibit a high recurrence rate depending on the distance of the tumor to the surgical resection margins. However, basal cell carcinomas rarely metastasize. Thus, they are considered to be ‘semi-malignant’ tumors.