How is morphology of squamous cell carcinoma?

➢ Squamous cell carcinomas in situ appear as sharply defined, red, scaling plaques; some appear to arise in association with prior actinic keratoses. ➢ Microscopically, squamous cell carcinoma in situ is characterized by highly atypical cells at all levels of the epidermis, with nuclear crowding and disorganization. ➢ More advanced, invasive squamous cell carcinomas are nodular, often scaly lesions that may undergo ulceration. ➢ Such tumors show variable degrees of differentiation, ranging from tumors with cells arranged in orderly lobules that exhibit extensive keratinization to neoplasms consisting of highly anaplastic cells with foci of necrosis and only abortive, singlecell keratinization (dyskeratosis)