Histopathologic features of multiple cutaneous squamous cell carcinomas of the lower extremity

Abstract

Recent studies suggest cutaneous squamous cell carcinomas (SCCs) of the leg, particularly those occurring multiply in sun exposed skin of nonimmunosuppressed women, are a distinct clinical subtype. There are few reports of the histopathologic features of this subtype. A retrospective chart review of 4 patients with multiple SCCs on the leg was performed and a total of 35 biopsies from the legs examined. Histopathologically, the tumors lacked adjacent actinic keratosis (AK) and often had adjacent basaloid retiform proliferations. Most lesions (all but one) were well differentiated and about 40% could be classified histopathologically as keratoacanthoma. Perineural invasion was absent in all but one case. Using the American Joint Committee on Cancer (AJCC) staging criteria for SCC, 21 tumors were Stage I, and 9 Stage II. During 7-10 years of follow-up, no recurrence or metastasis occurred. Patients with multiple SCCs on the lower extremities can have a range of histopathologic features, from keratoacanthoma-like to well-differentiated SCC.

Concomitant hypertrophic lichen planus and squamous cell carcinoma: Clinical features and treatment outcomes

“…In addition, the lack of defined pathologic criteria to distinguish between HLP and SCC represents a limitation. While our relatively small cohort limits broad generalizations, it corroborates the results of previous studies demonstrating good prognosis with multiple treatment modalities, including more conservative approaches, for SCCs in lower extremities in the general population 14 . Limitations of our study include its retrospective nature and small cohort due to the rarity of the HLP‐SCC phenomenon and limited availability of staging and size data.…”

“…While our relatively small cohort limits broad generalizations, it corroborates the results of previous studies demonstrating good prognosis with multiple treatment modalities, including more conservative approaches, for SCCs in lower extremities in the general population. 14 Limitations of our study include its retrospective nature and small cohort due to the rarity of the HLP-SCC phenomenon and limited availability of staging and size data. Further prospective studies would be beneficial to improving our understanding and management of patients with concomitant diagnoses of HLP and SCC.…”

A Rare Case of Invasive Keratinizing Squamous Cell Carcinoma of the Foot

“… 5 Solus et al 5 did an institutional review of 61 cSCC cases of the lower extremity and found that 69% of patients were female and 90% of the tumors were well-differentiated. Munday et al 6 recently did a retrospective chart review and analyzed the histopathology of SCC of the leg. They found most of the lesions were well-differentiated and keratoacanthoma like lesions were noted in approximately 40%.…”

A pilot study of p53 immunohistochemistry in atypical squamous lesions, using a vulvar scoring system

“…4 "Eruptive squamous atypia" is another term that encompasses KASP as well as other cSCC mimics. [10][11][12] KASP usually lack a background of actinic keratosis 11,12 as well as the canonical DNAbinding domain TP53 mutations associated with 60%-90% of cSCC. [13][14][15][16] In contrast to KA, lesions called KASP and eruptive squamous atypia do not seem to self-regress; all three of these terms similarly describe atypical squamous histopathology that mimics SCC.…”