This lesion was removed from the forehead of an 83-year-old man. Acantholytic squamous cell carcinomas are one of the few subtypes of squamous cell carcinoma worth mentioning in a pathology report, as they often behave more aggressively. They have a characteristic histology with rounded keratinocytes, or "acantholysis". The differential diagnosis may include acantholytic dermatoses, but the presence of infiltrative growth, mitoses and cytologic atypia should eliminate any uncertainty.
This portion of the lesion abuts a small nerve. Acantholysis is prominent, with associated dyskeratotic cells. The cells show pleomorphism and a mitotic figure is present in the right center of the field.