Paper II
Question
Microscopy of basal cell carcinoma of skin
Answer
Basal cell carcinoma microscopy shows nests, cords, and islands of basaloid tumour cells budding off from the epidermis and extending into the dermis. The tumour cells are small with hyperchromatic nuclei and scant cytoplasm, resembling normal epidermal basal cells. A characteristic feature is peripheral palisading of nuclei at the periphery of the tumour nests, along with retraction artefact (clefting) separating the tumour nests from the surrounding stroma. The stroma often shows mucinous change and a variable chronic inflammatory infiltrate.