A low-grade malignant proliferation of epidermal cells that recapitulates the basal cell layer of the normal epidermis or the adnexa. These neoplasms show no differentiation to any of the adnexal structures and may have epidermal contiguity which may be multifocal.
- Cannot distiguish from basal cell tumor on clinical evaluation
- Histopathology reveals the infiltrative nature of the tumor
Histology:There are histologic variants of basal cell carcinoma. These are:
A. Infiltrative type
May have an association with the overlying epidermis
Cords of primitive basaloid cells extend into the dermis and occasionally the subcutis
Tumor cells have small, hyperchromatic nuclei with scant cytoplasm
Mitotic figures may be numerous
Often an extensive proliferation of stromal fibroblasts
Tumor shows no adnexal differentiation which allows it to be differentiated from sebaceous epithelioma and infiltrative and malignant trichoepithelioma
B. Clear-cell type is uncommon.
Architecture is that of a solid basal cell carcinoma
Cells are large and polygonal
Cells have a clear or finely granular cytoplasm
Nuclei are ovoid and uniform, nucleoli small
Number of mitosis found may be quite variable.
Good following wide excision, may recur but metastasis not reported