Squamous cell carcinoma: from precursor lesions to high-risk variants

Abstract

Cutaneous squamous cell carcinoma is second only to basal cell carcinoma in its incidence within our population. It is among the most common types of neoplasm afflicting the human race. Most cases are related to exposure to sunlight. This initial portion of the chapter will focus upon the biologic progression that results in the ultimate development of fully formed squamous cell carcinoma. The latter portion will focus upon the histologic features of squamous cell carcinoma, which may be potential prognostic indicators. While pathologists currently provide clinicians with information about many histologic features that may affect the outcome for patients with melanoma, there is little impetus for similar behavior on the part of pathologists when diagnosing squamous cell carcinomas. This is largely due to the relatively low metastasis rate for these tumors compared with melanomas; however, it may be possible for pathologists to separate out those squamous cell carcinomas with a higher chance for recurrence and metastasis. This chapter will examine many of these histologic features and propose a rationale for including this information in pathology reports.

Molecular discrimination of cutaneous squamous cell carcinoma from actinic keratosis and normal skin

“…Some of the lesions that can be the most difficult to differentiate, such as actinic keratosis and squamous cell carcinoma in situ, display varying different degrees of keratinocyte dysplasia and are typically considered neoplastic conditions. 2 Although actinic keratosis is widely regarded as a neoplastic lesion that is a precursor to squamous cell carcinoma, some believe actinic keratosis is actually squamous cell carcinoma and should be treated as such. 3,4 However, there is a consensus that differentiating between actinic keratosis and squamous cell carcinoma is important, as there are prognostic differences and treatment implications for the patient.…”

Expressão de marcadores de proliferação celular e apoptose no carcinoma espinocelular de pele e ceratose actínica

“…Ao envolver toda a epiderme, a atipia de ceratinó-citos é denominada carcinoma espinocelular "in situ", e denomina-se ceratose actínica, 11,12 a atipia menos extensa, mais notada em basal e região parabasal. O diagnós-tico, em bases histológicas, é realizado, a partir da análi-se de fragmentos, biópsia de lesões de pele.…”

“…12 Em muitos casos, somente a análise histológica não revela o verdadeiro comportamento dessas lesões, podendo ser subestimadas clinicamente, quanto ao seu tratamento e acompanhamento. 13 É importante que o patologista contribua com informações adicionais, de valor prognóstico para o clínico.…”

Epidemiological and molecular features of cutaneous squamous cell carcinoma with perineural spread

“…72 They can also present as raised, erythematous, non-ulcerating nodules. 72 They are most commonly managed with surgical excision, yet other treatments can include curettage/cautery, photodynamic therapy, cryotherapy and radiotherapy.…”

“…72 They can also present as raised, erythematous, non-ulcerating nodules. 72 They are most commonly managed with surgical excision, yet other treatments can include curettage/cautery, photodynamic therapy, cryotherapy and radiotherapy. 74 Treatment is necessary due to the risk of local invasion, metastasis to regional lymph nodes and distant organs and death from disease.…”