Diagnostic value of CD10 and Bcl2 expression in distinguishing cutaneous basal cell carcinoma from squamous cell carcinoma and seborrheic keratosis

Keratoacanthoma versus Squamous-Cell Carcinoma: Histopathological Features and Molecular Markers

Considerable controversy exists within the field of dermatopathology in differentiating keratoacanthoma (KA) from squamous-cell carcinoma (SCC). KAs are rapidly growing, benign squamous tumors that are typically well differentiated. This controversy stems from the diverging perspectives on the management, classification, and diagnosis of each entity. Many believe that KAs are benign neoplasms in which intervention may be unnecessary since they are self-limiting and resolve on their own. On the other hand, SCC needs to be treated, as it carries significant morbidity and mortality risks. Early diagnosis and treatment are vital to prevent serious consequences of SCC. Nevertheless, KAs may resemble SCC grossly and microscopically. Various ancillary tests, including immunohistochemical (IHC) staining, have been proposed to differentiate between these entities, though mixed patterns of expression can limit the diagnostic utility of these techniques. Research into this topic is ongoing, with newer genetic and molecular findings illuminating the previously difficult-to-understand aspects of KA and increasing our understanding of this entity. In this review, KA and SCC will be compared along the lines of histological features, genetic, immune, and molecular markers, differential diagnosis, and management to clarify the similarities, differences, and misconceptions about both entities.

Establishment and molecular characterization of HCB-541, a novel and aggressive human cutaneous squamous cell carcinoma cell line

Cutaneous squamous cell carcinoma (cSCC) is a common type of skin cancer that can result in significant morbidity, although it is usually well-managed and rarely metastasizes. However, the lack of commercially available cSCC cell lines hinders our understanding of this disease. This study aims to establish and characterize a new metastatic cSCC cell line derived from a Brazilian patient. A tumor biopsy was taken from a metastatic cSCC patient, immortalized, and named HCB-541 after several passages. The cytokeratin expression profile, karyotypic alterations, mutational analysis, mRNA and protein differential expression, tumorigenic capacity in xenograft models, and drug sensitivity were analyzed. The HCB-541 cell line showed a doubling time between 20 and 30 h and high tumorigenic capacity in the xenograft mouse model. The HCB-541 cell line showed hypodiploid and hypotetraploidy populations. We found pathogenic mutations in TP53 p.(Arg248Leu), HRAS (Gln61His) and TERT promoter (C228T) and high-level microsatellite instability (MSI-H) in both tumor and cell line. We observed 37 cancer-related genes differentially expressed when compared with HACAT control cells. The HCB-541 cells exhibited high phosphorylated levels of EGFR, AXL, Tie, FGFR, and ROR2, and high sensitivity to cisplatin, carboplatin, and EGFR inhibitors. Our study successfully established HCB-541, a new cSCC cell line that could be useful as a valuable biological model for understanding the biology and therapy of metastatic skin cancer.

A Comparative Study of CD56 and Smooth Muscle Actin Expression in Basal and Squamous Cell Carcinomas

ABSTRACT

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the 2 most common types of nonmelanoma skin tumors. Clinical or histopathological diagnostic challenges are encountered on occasion. CD56 and smooth muscle actin (SMA) are highly expressed in BCCs. We aimed to investigate the frequency of these markers, along with B-cell lymphoma 2 (Bcl-2) and Ki67. This study was conducted to propose a method that could possibly be of diagnostic value. One hundred twenty-eight BCC and 39 SCC cases were included in this study. CD56, SMA, Bcl-2, and Ki67 immunohistochemical stains were applied. Ninety-nine (77.3%) BCC and 6 (15.4%) SCC cases showed CD56 immunoreactivity. SMA expression was detected in 78.1% of BCC and 5.1% of SCC cases. CD56, SMA, and Bcl-2 expressions were significantly higher in BCC cases. The Ki67 proliferation index was found significantly higher in SCC cases. When basosquamous carcinoma cases were compared with SCC cases, a significant correlation between tumors and expression of CD56, SMA, and Bcl-2 were obtained. CD56 and SMA, in addition to Bcl-2, favor BCC. Ki67 should also be included in the panel to demonstrate the proliferative activity.

Glioma-Associated Oncogene-1 Expression in Basal Cell Carcinoma and Its Histologic Mimics

ABSTRACT

Basal cell carcinoma (BCC) is the most common skin cancer, and it has numerous histologic mimics with variable prognoses and treatments. Although some immunohistochemical stains can be used for the differential diagnosis of BCC, variability and overlap in results can complicate their interpretation. Immunohistochemical staining for glioma-associated oncogene-1 (Gli-1) was performed on 26 nodular BCCs, 22 infiltrative BCCs, 9 basaloid squamous cell carcinomas, 12 desmoplastic trichoepitheliomas, 19 Merkel cell carcinomas, 11 sebaceous carcinomas, 10 cylindromas, 14 spiradenomas, 12 adenoid cystic carcinomas (AdCC), and 1 solitary trichoepithelioma. Strength of staining was scored as 0, 1+, 2+, or 3+, and distribution of staining was categorized as diffuse, multifocal, or focal. Strong, diffuse Gli-1 expression was seen in all tumors with basal epidermal-type differentiation, including BCC, trichoepithelioma, and basaloid squamous cell carcinoma. All examples of Merkel cell carcinoma were negative for cytoplasmic expression. Seven out of 11 sebaceous carcinomas were negative for Gli-1, and the remaining 4 showed 1+ expression. Cylindroma, spiradenoma, and AdCC, each an adnexal skin tumor, showed the most variable staining, but with cylindroma and spiradenoma demonstrating comparable labeling patterns. Overall, although Gli-1 may not distinguish between basal epidermal-type tumors, it may have a role in separating that group from lesions with adnexal differentiation, particularly sebaceous carcinoma, but also cylindroma, spiradenoma, and AdCC. Any cytoplasmic staining seems to exclude the diagnosis of Merkel cell carcinoma.

Unusual clinical manifestation of seborrheic keratosis on the scalp successfully treated with topical trichloroacetic acid: an atypical case report

Seborrheic keratoses (SKs) are benign tumor of the skin. They can occur anywhere, except the palms and soles. SKs commonly present as multiple, pigmented papules which is classically described as verrucous stuck-on papules or plaques. A case with multiple nodular appearance is a rare case and to our knowledge has never been reported. Here we report a rare case of multiple SKs on the scalp. On clinical evaluation, multiple, erythematous hyperkeratotic nodules were present. Dermoscopic and histopathological examination supported SKs. The patient was successfully treated with topical application of 80% TCA solution.

Exposure to fine particulate matter associated with senile lentigo in Chinese women: a cross-sectional study

BACKGROUND

Skin ageing especially senile lentigo directly affects self-esteem. For decades, senile lentigo has been associated with chronic exposure to solar radiation. However, a study conducted recently in Caucasian subjects suggested that exposure to air pollution was significantly correlated with extrinsic skin ageing, in particular senile lentigines.

OBJECTIVE

To investigate the association between fine particulate matter (PM_2.5 ) and skin ageing, particularly senile lentigo and seborrheic keratosis.

METHODS

The study enrolled 400 Chinese women aged 40-90 years including 210 from the Yanqing county in Beijing (low PM_2.5 exposure group) and 190 from the Xuanwumen in Beijing (high PM_2.5 exposure group). Skin ageing symptoms, particularly senile lentigines and seborrheic keratoses, were clinically assessed using scores of intrinsic and extrinsic skin ageing. An ordinal logistic regression model was used to analyse the effect of PM_2.5 on skin ageing adjusted for factors underlying skin ageing.

RESULTS

In the study population of Xuanwumen, we found that senile lentigo on cheeks and back of hands was 1.48 times and 2.8 times higher, respectively, compared with those from Yanqing county. However, no association was found between PM_2.5 and seborrheic keratosis. We found that other variables such as smoking, second-hand smoking, contact with fossil fuels and skin types were significantly associated with skin ageing.

CONCLUSION

These results indicate that PM_2.5 was another extrinsic factor promoting skin ageing.