Case 1: This basosquamous BCC contains a population of squamoid cells with abundant pink cytoplasm. In fact, you might need to hunt around for a more classic basaloid population to accurately make the diagnosis.

There are mitotic figures and apoptotic cells. Peripheral palisading and stromal retraction are often rare to absent.

Metatypical BCC (a.k.a. basosquamous BCC) is considered an aggressive subtype of BCC similar to morpheaform and infiltrative types (Crowson).

Areas of squamous differentiation (keratinization, intercellular bridging) are admixed with basaloid areas. The population of squamoid cells have pinker cytoplasm (Busam).

It may be difficult to distinguish between a squamous cell carcinoma and a basosquamous BCC in a small biopsy. Furthermore, mixed basal cell-squamous cell carcinomas (collision tumor) may also be a consideration (Crowson).

• Epidermis : Basal Cell Carcinoma