Basal cell carcinoma: biology, morphology and clinical implications

Cutaneous Basal Cell Carcinoma In Situ: A Review of the World Literature

Cutaneous basal cell carcinoma (BCC) in situ is a recently recognized subtype of the skin neoplasm in which the abnormal cells are confined to the epidermis. BCC in situ of the skin was previously referred to as a superficial BCC. A review of the world literature has revealed 10 cutaneous BCCs in situ that have been described in nine patients but likely reflect a more general phenomenon. The neoplasm typically presents as an asymptomatic red plaque on the abdomen, upper extremity, back, and chest. Pathologic changes frequently show confluent tumor cells along the epidermal basal layer or superficial aggregates of neoplastic cells that are contiguous with the epidermis and extend into the dermis. Genomic evaluation has been performed in neoplasms from one individual with cutaneous BCC in situ and metastatic BCC; like other variants of BCC, an aberration of the PTCH1 gene was observed. In contrast to his liver metastasis, the in situ carcinoma had a lower tumor mutational burden, lacked programmed death-ligand 1 (PD-L1) and programmed death-ligand 2 (PD-L2) amplification and had a distinct PTCH1 mutation, suggesting that the in situ BCC of his skin and the metastatic BCC of his liver were derived from different clones of cells.

Two Cases of Pigmented Basal Cell Carcinoma in African American Patients

Basal cell carcinoma (BCC) is the most common cutaneous malignancy, comprising approximately 80% of non-melanoma skin cancers. There are numerous subtypes, including pigmented basal cell carcinoma (pBCC), a rare clinical and histological variant. Skin cancers in African American patients, although rare, still do occur. BCC is an uncommon neoplasm in this population, but when it does occur, pigmentation is present in more than 50% of tumors compared with only 5% to 6% of BCCs in Caucasians. This report presents two cases of histologically verified pBCC in African American patients from dermatology clinics at the Veterans Affairs Hospital located in the Texas Medical Center. With the population of the United States growing more diverse, these cases emphasize the importance of recognizing the nuanced morphology of BCC in the skin of color compared to lighter-skinned counterparts. This is especially necessary, as early detection and prompt management are key to combating the disproportionately high morbidity and mortality related to skin cancers affecting patients of color.

Clinical versus Histological Assessment of Basal Cell Carcinoma Subtype and Thickness of Tumours Selected for Photodynamic Therapy

Photodynamic therapy is an approved treatment for primary, superficial, and small nodular basal cell carcinomas with a thickness of < 2 mm located on low-risk sites. Histologically verified basal cell carcinomas clinically assessed as suited for photodynamic therapy were included. The study aimed to investigate the agreement between clinical and histological assessments of basal cell carcinoma subtypes and thickness of tumours selected for photodynamic therapy with histopathological evaluation as a reference. A total of 343 tumours were included. The agreement between clinical and histological diagnosis of basal cell carcinoma subtype was 72% (p < 0.001). Clinical assessment of subtype had a sensitivity of 93% and specificity of 55% for superficial tumours and a sensitivity of 55% and specificity of 85% for nodular tumours. The mean ± SD thickness values by clinical and histological assessments were 0.95 ± 0.53 and 0.86 ± 0.75. The difference of 0.09 mm was statistically significant (p = 0.017), but not considered to be clinically relevant, although the differences between specific subgroups could be relevant. Among basal cell carcinomas clinically diagnosed as superficial, 91% were histologically consistent with the current photodynamic therapy criteria. The main results suggest that histopathological evaluation should precede photodynamic therapy to ensure selection of suitable basal cell carcinomas. In selected cases, the clinical diagnosis alone may be adequate before proceeding with photodynamic therapy.

Cutaneous Superficial Basal Cell Carcinoma is a Basal Cell Carcinoma In Situ: Electron Microscopy of a Case Series of Basal Cell Carcinomas

Basal cell carcinoma (BCC) is the most common skin cancer. Skin cancers may present either as a non-invasive tumor or an invasive malignancy. The terminology of carcinoma in situ is used when the tumor is either just limited to epidermis or not present as single cells or nests in the dermis. However, currently the terminology superficial BCC is inappropriately used instead of BCC in situ when the skin cancer is limited to epidermis. In this study we compare the pathologic changes of superficial, nodular, and infiltrative BCCs using electron microscopy to identify the ultrastructural characteristics and validate the previously proposed terminology. Three cases of BCC (superficial BCC, nodular BCC, and infiltrative BCC) diagnosed by dermatopathologists at our institute were selected for review. Paraffin block tissues from these cases were sent for electron microscopy studies which demonstrated disruption of basal lamina in both nodular and infiltrative type of BCC, while it remains intact in BCC superficial type after extensive examination. Therefore, similar to other in situ skin cancers, there is no invasion of the neoplasm in superficial BCC into the dermis. Hence, the older term superficial BCC should be appropriately replaced with the newer terminology BCC in situ.

Photodynamic Therapy for the Treatment of Basal Cell Carcinoma: A Comprehensive Review of Randomized Controlled Trials

INTRODUCTION

Basal cell carcinoma (BCC) is the most common skin cancer worldwide and has been reported to have a rising incidence in the last years. Multiple therapeutic modalities are approved for the treatment of BCC, making it difficult for physicians to choose the most suitable option for every patient. Photodynamic therapy (PDT) using either 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) as photosensitizing agents is an established treatment option for low-risk BCC.

OBJECTIVES

This review aims to summarize the available evidence from randomized clinical trials (RCTs) that utilize either ALA or MAL PDT and compare it with other treatment modalities. The main outcomes related to the effectiveness, adverse events, cosmetic outcomes and pain sensation, along with data from long-term follow-ups will be presented and discussed.

METHODS

Thorough literature searches were conducted through the electronic databases ClinicalTrials. gov and Pubmed/MEDLINE from inception up to 28 March 2023. Only studies in English were included. All relevant data were extracted accordingly from the eligible studies.

RESULTS

Eight RCTs included superficial BCC (sBCC) alone, 7 included nodular BCC (nBCC), 2 included both sBCC and nBCC and 1 included BCC of unspecified subtype. Follow-up duration ranged from 3 months to 5 years. Both ALA-PDT and MAL-PDT demonstrated acceptable efficacy, adverse events, cosmetic outcomes and pain sensation while no major differences were observed between them. PDT was less effective than surgery but with better reported cosmetic outcomes.

CONCLUSIONS

PDT is a safe and efficacious treatment option for sBCC and to a lesser extent nBCC.

New, simplified versus standard photodynamic therapy (PDT) regimen for superficial and nodular basal cell carcinoma (BCC): A single-blind, non-inferiority, randomised controlled multicentre study

BACKGROUND

Topical photodynamic therapy (PDT) is an approved and widely used treatment for low-risk basal cell carcinoma (BCC), comprising two sessions with an interval of 1 week. Simplification of the treatment course can be cost-effective, easier to organize, and cause less discomfort for the patients.

METHODS AND FINDINGS

We performed an investigator-initiated, single-blind, non-inferiority, randomized controlled multicentre study with the objective of investigating whether a simpler and more flexible PDT regimen was not >10% less effective than the standard double PDT in the treatment of primary, superficial, and nodular ≤2 mm-thick BCC and evaluate the cosmetic outcome. With a non-inferiority margin of 0.1 and an expected probability complete response of 0.85, 190 tumours were required in each group. Histologically verified BCCs from seven centres in Norway were randomly assigned (1:1) to either receive a new regimen of single PDT with one possible re-treatment of non-complete responding tumours, or the standard regimen. The primary endpoint was the number of tumours with complete response or treatment failure at 36 months of follow-up, assessed by investigators blinded to the treatment regimen. Intention-to-treat and per-protocol analyses were performed. The cosmetic outcome was recorded. The study was registered with ClinicalTrials.gov, NCT-01482104, and EudraCT, 2011-004797-28. A total of 402 BCCs in 246 patients were included; 209 tumours assigned to the new and 193 to the standard regimen. After 36 months, there were 61 treatment failures with the new and 34 failures with the standard regimen. Complete response rate was 69.5% in the new and 81.1% in the standard treatment group. The difference was 11.6% (upper 97.5% CI 20.3), i.e. > than the non-inferiority margin of 10%. Cosmetic outcomes were excellent or good in 92% and 89% following the new and standard regimens, respectively.

CONCLUSIONS

Single PDT with possible re-treatment of primary, superficial, and nodular ≤ 2-mm-thick BCC was significantly less effective than the approved standard double treatment. The cosmetic outcome was favorable and comparable between the two treatment groups.

Nodular Basal Cell Carcinoma in an Unusual Groin Location: A Rare Presentation

Basal cell carcinoma is the most frequent skin malignancy with a constant rise in its incidence. It affects typically the head and neck of elderly patients. However, the literature in English shows its occurrence in many uncommon locations. In our work, we report a case of basal cell carcinoma occurring in the groin region in a 66-year-old male patient, with no particular medical history. We also discuss through a literature review, the characteristics of this common neoplasm when it occurs in the groin and in other atypical locations.

Multiscale spatial mapping of cell populations across anatomical sites in healthy human skin and basal cell carcinoma

Our understanding of how human skin cells differ according to anatomical site and tumour formation is limited. To address this, we have created a multiscale spatial atlas of healthy skin and basal cell carcinoma (BCC), incorporating in vivo optical coherence tomography, single-cell RNA sequencing, spatial global transcriptional profiling, and in situ sequencing. Computational spatial deconvolution and projection revealed the localisation of distinct cell populations to specific tissue contexts. Although cell populations were conserved between healthy anatomical sites and in BCC, mesenchymal cell populations including fibroblasts and pericytes retained signatures of developmental origin. Spatial profiling and in silico lineage tracing support a hair follicle origin for BCC and demonstrate that cancer-associated fibroblasts are an expansion of a POSTN+ subpopulation associated with hair follicles in healthy skin. RGS5+ pericytes are also expanded in BCC suggesting a role in vascular remodelling. We propose that the identity of mesenchymal cell populations is regulated by signals emanating from adjacent structures and that these signals are repurposed to promote the expansion of skin cancer stroma. The resource we have created is publicly available in an interactive format for the research community.

The Importance of Basal Cell Carcinoma Risk Stratification and Potential Future Pathways

BACKGROUND

Basal cell carcinoma (BCC) is the most common human cancer. Although there are surgical and topical treatments available, surgery remains the mainstay of treatment, leading to higher costs. What is needed is an accurate risk assessment of BCC so that treatments can be planned in a patient-centered manner.

OBJECTIVE

In this study, we will review the literature about guidelines for the management of BCC and analyze the potential indicators of high-risk BCC. Using this risk assessment approach, we will propose pathways that will be able to optimize treatments more efficiently.

METHODS

This paper presents a perspective from a skin cancer expert and clinic involved in the treatment of both simple and complex cases of BCC. It addresses the key challenges associated with accurate risk stratification prior to any treatment or procedure. Different immunohistochemical and angiogenic markers for high-risk BCC were reviewed in this study.

RESULTS

The expression of interleukin-6, vascular endothelial growth factor, and mast cells within BCC correlates with its aggressiveness. Other immunohistochemical markers, such as Cyclin D1 and Bcl-2, also play a significant role-Cyclin D1 is higher in the aggressive BCC, while Bcl-2 is lower in the aggressive BCC, compared to the nonaggressive variants.

CONCLUSIONS

Based on our research, we will conclude that using immunohistochemical and angiogenic markers for risk assessment and stratification of BCC can help optimize treatment, ensuring that surgical procedures are used only when necessary.

Eccrine Poroma with Concurrent Basal Cell Carcinoma: A Rare Combination

Eccrine poroma (EP) is a benign skin appendicular tumor that differentiates into the terminal sweat duct and is often differentiated from basal cell carcinoma (BCC) and seborrheic keratosis. This report describes a 58-year-old woman who presented with left occipital plaque. Histopathological analysis showed that the tumor cells were located in the lower part of the epidermis. The tumor cells were cuboidal or circular basal-like cells of the same size. The surrounding cells were not arranged in a palisade shape. Scattered tumor clusters composed of basal-like cells were also seen in the dermis, staining basophilic, and the surrounding cells were arranged in a palisade pattern. Immunohistochemistry showed that BerEP4, epithelial membrane antigen EMA, carcinoembryonic antigen CEA, Bcl-2, CD10, CK7 were positive, AR, PAS were negative. According to the pathological examination and immunohistochemical results, a case of eccrine poroma with concurrent basal cell carcinoma was diagnosed.

Recommendations for Cost-Conscious Treatment of Basal Cell Carcinoma

BACKGROUND

Basal cell carcinoma (BCC) affects 3.3 million Americans annually. Treatment modalities for BCC include many surgical and nonsurgical options. The cost of BCC treatment can pose a substantial burden to patients and the healthcare system. Cost can be an important consideration in BCC treatment planning.

OBJECTIVE

We present an approach to the management of BCC when cost reduction is a priority.

METHODS

A PubMed literature search identified studies on effectiveness of current BCC therapies. Treatment prices were obtained from the Medicare National Fee Schedule, GoodRx, and pharmaceutical companies. The American Academy of Dermatology's (AAD) guidelines for treating BCC were used to develop recommendations for cost-reductive treatment.

RESULTS

The cost of treating a primary superficial BCC < 0.5 cm arising on Area M (cheeks, forehead, scalp, neck, jawline, pretibial surface) was $143 with curettage and electrodesiccation (C&E), $143 with cryosurgery, $210 with standard excision and simple reconstruction (SE), $1221 with Mohs Micrographic Surgery (MMS) and simple reconstruction, $472 with imiquimod, $186 with 5-fluorouracil (5-FU), and $354-$371 for photodynamic therapy (PDT). The cost of treating a primary nodular BCC 1.1-2 cm arising on Area L (trunk and extremities, excluding pretibial surface, hands, feet, nail units and ankles) was $183 with C&E, $183 with cryosurgery, $251 with SE and simple reconstruction, $1163-1351 with MMS and simple reconstruction, $472 with imiquimod, $186 with 5-FU, and $354-$371 for photodynamic therapy (PDT). The cost of treating a giant BCC (BCC > 10 cm with aggressive behavior) was $465-3311 with radiation, $139,560 with vismodegib, $144,452 with sonidegib, ~ $44.5 with cisplatin (medication cost only), and at least $184,836 with cemiplimab-rwlc.

CONCLUSIONS

For a primary superficial BCC < 0.5 cm arising on Area M, the cost-conscious algorithm prioritizes C&E or cryosurgery. For a primary nodular BCC 1.1-2 cm arising on Area L, the cost-conscious algorithm prioritizes C&E, cryosurgery, or 5-FU. For a giant BCC, the cost-conscious algorithm identifies superficial radiation therapy as first line.

Recurrence of Basal Cell Carcinoma Treated with Surgical Excision and Histopathological Analysis with Frozen Section Technique with Complete Margin Control (CMC-FS): A 15-Year Experience of a Reference Center

BACKGROUND

Basal cell carcinoma (BCC) is the most common type of eyelid malignancy and it is considered to be dangerous due to its proximity to functionally essential organs. Early diagnosis and complete excision of the primary lesion are crucial to prevent infiltration and metastasis. The study aims to evaluate the extent of recurrence in subjects affected by BCC of the upper third of the face treated with surgical eradication and the frozen section technique with complete margin control (CMC-FS), in comparison with the gold standard Mohs micrographic surgery (MMS).

MATERIALS AND METHODS

The study included 111 patients with 111 biopsy-proven eyelid BCCs. On clinical examination, all lesions were removed with 2 mm margins clinically free of neoplasm. Prior to reconstruction, CMC-FS analysis of all surgical margins was performed on each tumor for histopathologic confirmation. Subsequently, all margins were presented for the permanent paraffin sections.

RESULTS

There were 69 primary carcinomas and 42 secondary carcinomas among the 111 samples. No recurrence occurred in 109 tumors followed-up for at least 5 years, with a total recurrence rate of 1.8%. The median time between lesion excision and diagnosis of recurrence was 20 months.

CONCLUSIONS

at 5-year follow-up, CMC-FS guided excision of BCCs of the eyelids resulted in recurrence rates equivalent to MMS. Intraoperative microscopic control of all margins reduced the recurrence rate of the upper third of the facial BCCs, correlating with easier reconstruction with better esthetic and functional outcome.

Comparison of Sonographic Characteristics Between Superficial Basal Cell Carcinoma and Non-Superficial Basal Cell Carcinomas

OBJECTIVES

To compare the sonographic characteristics of superficial basal cell carcinoma (sBCC) and non-superficial basal cell carcinomas (nsBCC).

METHODS

The ultrasound characteristics of 73 basal cell carcinoma (BCC) confirmed by surgical pathology were retrospectively analyzed, and the cases were divided into 11 cases of sBCC and 62 cases of nsBCC according to pathological subtypes. Ultrasound characteristics between groups were compared.

RESULTS

Among all the ultrasound characteristics, lesion thickness (P = .000), shape (χ²  = 39.293, P = .000), basal changes (χ²  = 8.473, P = .037), infiltration level (χ²  = 46.140, P = .000), and distribution of intralesional hyperechogenic spots (χ²  = 15.699, P = .000) of the lesions had statistically significant correlation with pathological diagnosis of sBCC. While no significant differences were shown in surface morphology, keratinization, maximum diameter, intralesional echogenicity, posterior echogenic changes, and intralesional color Doppler flow of the lesions.

CONCLUSIONS

Small lesion thickness, oblate shape, superficial dermal local infiltration, and <3 internal hyperechogenic spots distribution of BCC determined by high frequency ultrasound may positively correlate with pathological diagnosis of sBCC. This is beneficial for treatment planning.

Weakly supervised detection and classification of basal cell carcinoma using graph-transformer on whole slide images

The high incidence rates of basal cell carcinoma (BCC) cause a significant burden at pathology laboratories. The standard diagnostic process is time-consuming and prone to inter-pathologist variability. Despite the application of deep learning approaches in grading of other cancer types, there is limited literature on the application of vision transformers to BCC on whole slide images (WSIs). A total of 1832 WSIs from 479 BCCs, divided into training and validation (1435 WSIs from 369 BCCs) and testing (397 WSIs from 110 BCCs) sets, were weakly annotated into four aggressivity subtypes. We used a combination of a graph neural network and vision transformer to (1) detect the presence of tumor (two classes), (2) classify the tumor into low and high-risk subtypes (three classes), and (3) classify four aggressivity subtypes (five classes). Using an ensemble model comprised of the models from cross-validation, accuracies of 93.5%, 86.4%, and 72% were achieved on two, three, and five class classifications, respectively. These results show high accuracy in both tumor detection and grading of BCCs. The use of automated WSI analysis could increase workflow efficiency.

Perianal Basal Cell Carcinoma-A Systematic Review and Meta-Analysis of Real-World Data

(1) Background: BCC is a sporadic disease that develops in areas of the skin not exposed to the sun. Perianal BCC, which occurs in the anorectal region, accounts for less than 0.2% of all BCC cases. There have been only a few reported cases of the disease, with fewer than 200 cases reported in total. Given the diagnostic challenges and potential for misdiagnosis, we conducted a systematic review of perianal basal cell carcinoma using real-world data to provide comprehensive and detailed information on the disease. (2) Methods: The study was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 2020. Patients' clinical pathologic features, tumor characteristics, treatment modalities, and outcomes were presented. (3) Results: The results of 41 studies involving 140 patients were analyzed. The most common symptoms reported by patients at presentation were anorectal bleeding, pain, and pruritus. Ulceration was the most frequently observed tumor characteristic. The majority of patients underwent local excision as their primary treatment, with only eight patients experiencing a recurrence. Our analysis did not reveal any statistically significant differences in the outcomes of different treatment modalities. (4) Conclusions: Identifying perianal BCC poses a significant challenge as it closely resembles other anal diseases, thereby making it difficult to differentiate between the different conditions. However, a wide local excision with clear margins is considered an effective treatment option for most patients. Alternative treatments, such as radiotherapy, may be recommended for patients who are unable to undergo surgery.

Pagetoid Spread in Basal Cell Carcinoma: Potential for Misdiagnosis

ABSTRACT

Basal cell carcinomas are one of the most common cutaneous carcinomas and show classical histologic features of basaloid nests with peripheral palisading. Pagetoid and intraepidermal spread has not been described in basal cell carcinoma to the best of our knowledge. We report 5 cases of basal cell carcinoma with classic histologic patterns and overlying basaloid nests and single intraepidermal tumor cells. A panel of immunostains were performed that included CK7, MOC31, CEA-m, EMA, androgen receptor, and Bcl2. Most of our cases were positive for both MOC31 and CK7, and all cases were negative for CEA-m and EMA excluding extramammary Paget disease, one of the most common differential diagnoses. These cases expand the spectrum of findings that can be seen in basal cell carcinoma and can help prevent misdiagnoses of basal cell carcinomas as more aggressive tumors.

Periocular basal cell carcinoma recurrence following surgical treatment: Safe surveillance time

BACKGROUND

To report the rate of primary periocular BCC recurrence following surgical excision in low-risk and high-risk BCCs, and to propose long term follow up guidelines.

METHODS

Retrospective case series of primary BCC treated with surgical excision (Mohs micrographic surgery [MMS], wide local excision [WLE] or fast paraffin excision) who have histologically-confirmed BCC subtype and histologically-measured tumour clearance margins.

RESULTS

77 patients (78 eyelids) were included. Mean age was 72.0 ± 12.8 years with a female predominance (42, 54.5%). Most common histological BCC subtype was nodular (39, 50.0%). 44 (56.47.1%) patients underwent MMS. Tumour clearance was achieved in 59 (75.6%) eyelids after one surgery. 9 had further surgery to achieve tumour clearance while 10 were monitored. There was no statistical significance between recurrence rates in patients who had tumour clearance compared with patients with incomplete tumour clearance after initial surgery (p = 0.15). In patients with incomplete tumour clearance, there was no statistical significance between recurrence rates in those who underwent further surgery versus those monitored (p = 0.47). Average follow-up duration was 37.9 ± 17.2 months. Three (3.9%) cases had recurrent BCC. All three cases had high-risk BCC features (infiltrative subtypes and/or incomplete tumour excision after initial surgery).

CONCLUSIONS

There was no evidence of recurrence of completely excised, low-risk BCCs at three years, regardless of type of surgical excision. We recommend patients with completely excised, primary BCCs without high-risk features be monitored for one year. Patients with any high-risk BCC features, such as incompletely excised tumours or high-risk histological subtypes, should be monitored for five years.

Occurrence of Human Defensins and S100 Proteins in Head and Neck Basal Cell Carcinoma (BCC) Entities: hBD3 and S100A4 as Potential Biomarkers to Evaluate Successful Surgical Therapy

Background: The goal of this study is the identification of potential marker molecules for characterizing different basal cell carcinoma entities, to help improve clinical decisions for surgical resection therapy. Methods: Three different entities, sclerodermiform, solid and superficial basal cell carcinomas, were subjected to immunohistochemical microscopy and histomorphometric analyses for human α- (DEFA1/3; DEFA4) and β-defensins (hBD1/2/3) and special S100 proteins (S100A4/7/8/9). Thirty specimens of the three entities were evaluated. Analyses were performed by comparing tissue and cellular localization and staining intensities of tumorous with non-tumorous areas. Staining intensities were semiquantitatively examined by using an RGB-based model. Results: Human defensins are present in all three entities of basal cell carcinomas. They all show cytoplasmic immunostaining in cells of the epithelium, stroma and tumor. Notably, human β-defensin3 is accumulated in the cell nuclei of sclerodermiform and superficial basal cell carcinomas. S100A4 and A7 are undetectable in tumor regions. However, S100A4 occurs in cancer-associated stroma cells with nuclear staining in superficial basal cell carcinomas. Conclusion: Two candidates, namely hBD3 and S100A4, might be used as potential clinical tools for evaluating successful surgical resection therapy to avoid aesthetic and functional facial deformation.

CD56 and smooth muscle actin immunoreactivity in basal cell carcinomas: Are they indicators of differentiation or do they hold a diagnostic use?

BACKGROUND

Basal cell carcinoma (BCC) is the most common cutaneous malignancy and may show various differentiations. The possible pluripotent stem cell lineage of BCCs, whose origins are controversial today, is thought to be the main reason for the different morphologies. The aim of the study is to evaluate the expression of some neuroendocrine and smooth muscle markers of differentiation in BCCs and investigate the relationship between histopathologic subtypes and recurrence.

METHODS

A total of 128 cases diagnosed as BCC in our center were included. Immunohistochemical studies of CD56, synaptophysin, chromogranin-A, smooth muscle actin (SMA), desmin, caldesmon, and Ki67 were applied.

RESULTS

CD56, chromogranin-A, and synaptophysin immunoreactivity were detected in 77.3%, 13.3%, and 0.8% of the cases, respectively. 78.1% showed SMA positivity while no tumor expressed desmin or caldesmon. A correlation between histopathologic recurrence risk groups and CD56 expression was found (p < 0.05).

CONCLUSIONS

CD56 and SMA immunoreactivity is present in the majority of BCCs. However, the available findings do not support neuroendocrine or smooth muscle differentiation. CD56 antigen can be used for prognostic purposes in detecting high recurrence risk tumors. After the investigation of the expression rates of these two antigens in different cutaneous tumors, it may be appropriate to use them for diagnostic purposes in BCCs.

[Translated article] Interventions for Basal Cell Carcinoma: Summary of Main Comparisons From a Cochrane Review and a Practical Interpretation of Findings

Numerous surgical and nonsurgical modalities are available to treat basal cell carcinoma (BCC), but their true effectiveness and safety is unknown. This article summarizes the evidence presented in a recent Cochrane review and aims to facilitate the interpretation of the review's findings for the Spanish and Latin American scientific communities. Much of the evidence the reviewers found came from single studies, preventing meta-analysis. Conventional surgical excision continues to be the most effective treatment for low-risk BCC. Most studies had small sample sizes, and some had problems with blinding, limitations which will have affected the assessment of subjective outcomes, such as pain and cosmetic results. The authors identified a lack of standardization in relation to recurrences and cosmetic outcomes that threatens not only the internal validity of the studies but also their external validity and reproducibility.

Interventions for Basal Cell Carcinoma: Summary of Main Comparisons From a Cochrane Review and a Practical Interpretation of Findings

Numerous surgical and nonsurgical modalities are available to treat basal cell carcinoma (BCC), but their true effectiveness and safety is unknown. This article summarizes the evidence presented in a recent Cochrane review and aims to facilitate the interpretation of the review's findings for the Spanish and Latin American scientific communities. Much of the evidence the reviewers found came from single studies, preventing meta-analysis. Conventional surgical excision continues to be the most effective treatment for low-risk BCC. Most studies had small sample sizes, and some had problems with blinding, limitations which will have affected the assessment of subjective outcomes, such as pain and cosmetic results. The authors identified a lack of standardization in relation to recurrences and cosmetic outcomes that threatens not only the internal validity of the studies but also their external validity and reproducibility.

Diagnosis and management of basal cell carcinoma: interdisciplinary consensus statements of Jose R. Reyes Memorial Medical Center, a Department of Health Tertiary Hospital in Manila, Philippines

BACKGROUND

Basal cell carcinoma (BCC) is the most common cutaneous malignancy. Multiple risk factors are associated in the development of BCC, with ultraviolet light and genetics playing major roles.

AIMS

The departments of dermatology, medical oncology, ophthalmology, otorhinolaryngology, head and neck surgery, plastic surgery, and radiation oncology of the Jose R. Reyes Memorial Medical Center, Manila, Philippines, have convened and formulated consensus statements on the diagnosis and management of BCC patients seen in the institution.

CONCLUSION

The summary of the recommendations is: (1) Surgery is the treatment of choice for BCC. The range of margins (2-4 mm) depends on the type of BCC. (2) Mohs micrographic surgery (MMS) is indicated for high risk BCC. (3) Topical treatment with imiquimod or 5-flourouracil (5-FU) may be used for superficial BCC. (4) Destructive methods (cryotherapy, curettage and electrodessication, photodynamic therapy) may be used for low risk BCC. (5) Medical and/or radiation therapy is advised for cases where surgery is contraindicated or tumor is not amenable to surgery. Metastasis of this malignancy is rare. Follow-up, which may continue up until 2 years, is recommended for high risk BCC.

Use of Cytokeratin 17 in the Differentiation Between Desmoplastic Trichilemmoma and Cutaneous Basal Cell Carcinoma

ABSTRACT

Desmoplastic trichilemmoma (DTL) is a variant of trichilemmoma characterized by a prominent desmoplastic stroma that may mimic invasive carcinoma. These lesions typically show features of a conventional trichilemmoma at the periphery, surrounding dense hyalinized stroma with entrapped cords of tumor cells. On a small or superficial biopsy, DTL may pose a diagnostic challenge in distinguishing this benign adnexal neoplasm from invasive carcinoma, particularly basal cell carcinoma (BCC). We aimed to investigate whether the immunohistochemical expression of cytokeratin 17 (CK17) would be useful in the differentiation between DTL and BCC. CK17 is expressed in normal adnexal structures and has been shown to demonstrate strong staining in BCCs. Expression of CK17 was examined in 23 cases of DTL and 23 BCCs. An immunoreactivity score was assigned using the percentage of tumor cells staining with scoring as follows: 0, complete negativity; 1, < 15% tumor cells staining; 2, 15%-84% tumor cells staining; and 3, >85% staining. All cases of BCC scored as 3, whereas 18% of DTL scored as 3. The mean percent staining for CK17 was significantly higher for BCCs (97% of tumor cells) than DTLs (57% of tumor cells); P < 0.001 in the unpaired t test. The pattern of CK17 staining may also help differentiate between cases scoring 3. All BCCs showed strong diffuse staining throughout, whereas for those cases of DTL with a score of 3, the peripheral basaloid rim in the tumor lobules did not stain. CK17 is a useful adjunct in distinguishing DTL from BCC in small or superficial biopsy specimens.

Basal cell skin cancers: Retrospective analysis of 67 cases

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin cancer and originates from the basal layer of the epidermis. It is most common in the head and neck region. It usually grows slowly and rarely metastasizes. The gold standard treatment is surgical excision.

AIMS

In this study, it was aimed to discuss the demographic and medical data of patients treated with the diagnosis of BCC.

PATIENTS/METHODS

Sixty-seven tumors of 55 patients who were operated for BCC in our clinic between 2016 and 2020 were retrospectively analyzed. Demographic and medical data were analyzed.

RESULTS

The tumor was most commonly localized to the nose. The most common (50%) histological type was the nodular type. Recurrence occurred in one of our patients (1.5%). Surgical margin positivity was observed in six patients.

CONCLUSIONS

Basal cell carcinomas are most common in the head and neck region. Its frequency increases with age and is more common in men. In our patients, 98.5% of the tumors were located in the head and neck, and 89.5% were over 60 years of age. Nodular is the most common type of BCC, and the most common nodular type was detected in our study. Surgical margin positivity is observed between 9% and 37.2% after surgery, and the recurrence rate is around 5%. In our study, surgical margin positivity was 9% and recurrence was 1.5%. Evaluating the excision margins carefully in a well-lit environment and taking into account cosmetic concerns, obtaining an adequately intact surgical margin in one go may lead to the ideal treatment result.

Overview of familial syndromes with increased skin malignancies

The vast majority of skin cancers can be classified into two main types: melanoma and keratinocyte carcinomas. The most common keratinocyte carcinomas include basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Multiple familial syndromes have been identified that can increase the risk of developing SCC, BCC, and/or melanoma. The major syndromes include oculocutaneous albinism for SCC, basal cell nevus syndrome for BCC, familial atypical multiple mole-melanoma syndrome, and hereditary breast and ovarian cancer syndrome for melanoma. In addition, familial syndromes that can predispose individuals to all three major skin cancers include xeroderma pigmentosum and Li-Fraumeni syndrome. This review highlights the epidemiology, risk factors, pathogenesis, and etiology of the major and minor syndromes to better identify and manage these conditions. Current investigational trials in genomic medicine are making their way in revolutionizing the clinical diagnosis of these familial syndromes for earlier preventative measures and improvement of long-term prognosis in these patients.

Basal cell carcinoma in an albino pindani (Chindongo socolofi) and a cobalt-zebra (Maylandia callainos): Diagnostic imaging, clinical and histopathological study

A female albino pindani (Chindongo socolofi) and female cobalt-zebra (Maylandia callainos) were referred to the Ornamental Fish Clinic with a soft tissue mass on their upper jaw. Also, during clinical examination, an unencapsulated intraoral soft tissue mass was observed in the cobalt-zebra cichlid. Digital radiography showed soft tissue masses and osteolytic lesions. Computed tomography (CT) imaging confirmed that osteolytic lesions occurred in skull bones of cobalt-zebra. Also, soft tissue mass invaded to the intraoral space. Histopathologically, a non-encapsulated, multilobulated and densely cellular neoplastic mass was identified. Extensive infiltration of neoplastic cells to the dermis and subcutaneous tissue was observed in both cases. The masses were composed of multiple coalescing nests, sheets, lobules and trabeculae of neoplastic cells within a fibrovascular stroma. The palisading basaloid neoplastic cells were markedly extended from the basal cells of the epidermis into the dermis and subcutis. The majority of the neoplastic cells had scant amounts of eosinophilic cytoplasm with indistinct margins, round to ovoid nuclei and typically a single small basophilic nucleolus. There was invasion of basaloid neoplastic cells into the bone tissue that caused osteolytic lesions. Mitotic figures were three to seven per high-power field. Epidermal basement membrane was periodic acid-Schiff (PAS) positive and neoplastic cell extension into the dermis was identified by the PAS staining. Fibrovascular stroma of the mass was also stained blue with Masson's trichrome. Based on histopathological and histochemical findings, the masses were diagnosed as infiltrative type of basal cell carcinoma (BCC).

Integrated multi-omics reveals cellular and molecular interactions governing the invasive niche of basal cell carcinoma

Tumors invade the surrounding tissues to progress, but the heterogeneity of cell types at the tumor-stroma interface and the complexity of their potential interactions hampered mechanistic insight required for efficient therapeutic targeting. Here, combining single-cell and spatial transcriptomics on human basal cell carcinomas, we define the cellular contributors of tumor progression. In the invasive niche, tumor cells exhibit a collective migration phenotype, characterized by the expression of cell-cell junction complexes. In physical proximity, we identify cancer-associated fibroblasts with extracellular matrix-remodeling features. Tumor cells strongly express the cytokine Activin A, and increased Activin A-induced gene signature is found in adjacent cancer-associated fibroblast subpopulations. Altogether, our data identify the cell populations and their transcriptional reprogramming contributing to the spatial organization of the basal cell carcinoma invasive niche. They also demonstrate the power of integrated spatial and single-cell multi-omics to decipher cancer-specific invasive properties and develop targeted therapies.

The role of reciprocal tumour-stroma interactions in tumour invasion remains poorly characterised. Here, single-cell and spatial transcriptomics identifies the cell populations and their transcriptional reprogramming contributing to the spatial organization of the basal cell carcinoma invasive niche.

Periocular basal cell carcinoma results and surgical outcome during a 5-year period in a larger Danish population

Background

To report tumour pathology, surgical procedure, complication rates and overall outcome of periocular basal cell carcinoma (BCC) in the Department of Ophthalmology at Sygehus Lillebaelt, Southern Denmark Region over a 5-year period.

Methods

Medical records for all patients who underwent surgery for periocular BCC between January 2016 and December 2020 were reviewed. All tumours were excised with a 3 mm margin beyond the clinically apparent delimitation of the tumour and analysed by frozen section histological examination. Paraffin sections were subsequently examined for a final histopathological diagnosis. Patient age, gender, date of resection, former cancer history, referring unit and follow-up time were recorded. Furthermore, histological subtypes identified from biopsy and resection, lesion location, lesion diameter, free margin after the first operation, lacrimal punctum involvement, reconstructive techniques and complications were also recorded.

Results

A total of 242 surgical excisions from 237 patients were recorded. The mean age was 69.7 ± 12.6 with women significantly predominant compared to men (1.8:1, p < 0.0001, binomial test). The mean tumour diameter was 4.29 mm (range 0.5–20 mm). The most common location and histological subtype was the lower eyelid and nodular BCC respectively (64.9% and 74.0% of cases). In 17.4% of the patients, the initial resection margin on the frozen section histology was not free of tumour cells and the risk was significantly greater for BCC subtypes considered aggressive in terms of growth pattern (morphea form, infiltrative and micronodular features) as compared to non-aggressive BCC subtypes (nodular and superficial) (p = 0.002, X²). In 239 (98.8%) of the patients, the BCC was found to be radically removed after final histopathological examination.

The sensitivity of identification of aggressive subtypes of periocular BCC in biopsies was 47.7%. No recurrences were found during the 5-year period.

Conclusion

This study demonstrated a tendency towards more women than men being diagnosed with periocular BCC. The initial biopsy performed for all patients underestimated the aggressiveness of BCC in almost half of the cases while aggressive BCC subtypes were more likely to need further resection after frozen section compared to non-aggressive subtypes.

Basal cell carcinomas acquire secondary mutations to overcome dormancy and progress from microscopic to macroscopic disease

Basal cell carcinomas (BCCs) frequently possess immense mutational burdens; however, the functional significance of most of these mutations remains unclear. Here, we report that loss of Ptch1, the most common mutation that activates upstream Hedgehog (Hh) signaling, initiates the formation of nascent BCC-like tumors that eventually enter into a dormant state. However, rare tumors that overcome dormancy acquire the ability to hyperactivate downstream Hh signaling through a variety of mechanisms, including amplification of Gli1/2 and upregulation of Mycn. Furthermore, we demonstrate that MYCN overexpression promotes the progression of tumors induced by loss of Ptch1. These findings suggest that canonical mutations that activate upstream Hh signaling are necessary, but not sufficient, for BCC to fully progress. Rather, tumors likely acquire secondary mutations that further hyperactivate downstream Hh signaling in order to escape dormancy and enter a trajectory of uncontrolled expansion.

Trieu et al. generate BCC mouse models in which rare macroscopic tumors form alongside numerous failed microscopic lesions. Successful macroscopic tumors acquire secondary changes that elevate Gli1, Gli2, and/or Mycn levels, causing hyperactivation of downstream Hedgehog (Hh) signaling. Loss of p53 and Notch1 also contributes to tumor progression.

2021 international consensus statement on optical coherence tomography for basal cell carcinoma: image characteristics, terminology and educational needs

BACKGROUND

Despite the widespread use of optical coherence tomography (OCT) for imaging of keratinocyte carcinoma, we lack an expert consensus on the characteristic OCT features of basal cell carcinoma (BCC), an internationally vetted set of OCT terms to describe various BCC subtypes, and an educational needs assessment.

OBJECTIVES

To identify relevant BCC features in OCT images, propose terminology based on inputs from an expert panel and identify content for a BCC-specific curriculum for OCT trainees.

METHODS

Over three rounds, we conducted a Delphi consensus study on BCC features and terminology between March and September 2020. In the first round, experts were asked to propose BCC subtypes discriminable by OCT, provide OCT image features for each proposed BCC subtypes and suggest content for a BCC-specific OCT training curriculum. If agreement on a BCC-OCT feature exceeded 67%, the feature was accepted and included in a final review. In the second round, experts had to re-evaluate features with less than 67% agreement and rank the ten most relevant BCC OCT image features for superficial BCC, nodular BCC and infiltrative and morpheaphorm BCC subtypes. In the final round, experts received the OCT-BCC consensus list for a final review, comments and confirmation.

RESULTS

The Delphi included six key opinion leaders and 22 experts. Consensus was found on terminology for three OCT BCC image features: (i) hyporeflective areas, (ii) hyperreflective areas and (iii) ovoid structures. Further, the participants ranked the ten most relevant image features for nodular, superficial, infiltrative and morpheaform BCC. The target group and the key components for a curriculum for OCT imaging of BCC have been defined.

CONCLUSION

We have established a set of OCT image features for BCC and preferred terminology. A comprehensive curriculum based on the expert suggestions will help implement OCT imaging of BCC in clinical and research settings.

Giant basal cell carcinoma of anterior chest wall reveals metastasis to lungs: A case report

Basal cell carcinoma (BCC) is the most common cutaneous malignancy in the world, and the incidence of pulmonary metastasis is exceedingly rare. We present a case of middle-aged male with findings consistent with BCC with metastasis to the lungs managed with surgical resection and the use of targeted therapy using the hedgehog pathway inhibitor with improvement.

Diagnosing Basal Cell Carcinoma of the Vulva: A Case Report and Review of the Literature

Basal cell carcinoma (BCC) is a highly prevalent epidermal neoplasm that most commonly occurs in regions of sun-exposed skin, though rare cases arise in sun-protected areas. BCCs of the vulva account for a small fraction of cases and can be mistaken for other cutaneous genital pathologies on clinical examination. Here we report a case of vulvar BCC that presented as a firm, tender bilateral lesion of the mons pubis and was diagnosed by histopathology and immunostaining for classical BCC markers.

Non-surgical treatments for basal cell skin cancer

Basal cell carcinoma is the most common nonmelanoma skin cancer. It originates from undifferentiated cells in the basal cell layer of the epidermis or from the outer root sheath of the hair follicle. The most important factor in development of basalioma is ultraviolet radiation. Surgery is considered the gold standard of treatment for basal cell cancer. However, nonsurgical options are available for individuals who are unsuitable for surgery. The purpose of this review is to summarize the efficacy and indications of alternative, nonsurgical treatments that can be used in the management of basal cell cancer Effective nonsurgical treatments include destructive methods (eg, curettage and electrodessication, cryosurgery, laser), photodynamic therapy, topical medications, hedgehog pathway inhibitors. Nonsurgical therapeutic alternatives are safe and effective for the treatment of BCC. Factors such as tumor location, size, and histopathological subtype should be taken into consideration when selecting optimal treatment, cosmetic results and patient preference should be considered too. To search for the necessary literature, the PubMed, MedLine, Web of Science and RSCI databases were used.

Incidence and trends of basal cell carcinoma in Sweden: A population-based registry study

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin cancer. Incidence is largely unknown because of incomplete, or lack of, registration in most countries.

OBJECTIVES

To assess current incidence rates and recent trends for BCC in the Swedish population.

METHODS

Patient- and tumour-related features of all histologically confirmed BCC tumours diagnosed in Sweden from 2004 to 2017 were extracted from the population-based Swedish BCC Registry. Incidence rates were standardized to the 2013 European Standard Population and trends were analysed using Poisson regression models.

RESULTS

Age-standardized person-based incidence rate of BCC in Sweden in 2017 was 405/100 000, rising from 308/100 000 in 2004, corresponding to an annual relative increase of 1.8% (women, 2.1%; men, 1.4%). Incidence was highest in the elderly and the most common tumour site was the head and neck. In 2017, the most common BCC subtypes were nodular and micronodular/infiltrative BCC (each 31%). Incidence of aggressive BCC subtypes increased faster than other subtypes.

CONCLUSIONS

BCC incidence rates in Sweden are relatively high and increasing. The increasing trends were more pronounced in women and for aggressive BCC subtypes.

Profile of Basal Cell Carcinoma Mutations and Copy Number Alterations - Focus on Gene-Associated Noncoding Variants

Basal cell carcinoma (BCC) of the skin is the most common cancer in humans, characterized by the highest mutation rate among cancers, and is mostly driven by mutations in genes involved in the hedgehog pathway. To date, almost all BCC genetic studies have focused exclusively on protein-coding sequences; therefore, the impact of noncoding variants on the BCC genome is unrecognized. In this study, with the use of whole-exome sequencing of 27 tumor/normal pairs of BCC samples, we performed an analysis of somatic mutations in both protein-coding sequences and gene-associated noncoding regions, including 5'UTRs, 3'UTRs, and exon-adjacent intron sequences. Separately, in each region, we performed hotspot identification, mutation enrichment analysis, and cancer driver identification with OncodriveFML. Additionally, we performed a whole-genome copy number alteration analysis with GISTIC2. Of the >80,000 identified mutations, ~50% were localized in noncoding regions. The results of the analysis generally corroborated the previous findings regarding genes mutated in coding sequences, including PTCH1, TP53, and MYCN, but more importantly showed that mutations were also clustered in specific noncoding regions, including hotspots. Some of the genes specifically mutated in noncoding regions were identified as highly potent cancer drivers, of which BAD had a mutation hotspot in the 3'UTR, DHODH had a mutation hotspot in the Kozak sequence in the 5'UTR, and CHCHD2 frequently showed mutations in the 5'UTR. All of these genes are functionally implicated in cancer-related processes (e.g., apoptosis, mitochondrial metabolism, and de novo pyrimidine synthesis) or the pathogenesis of UV radiation-induced cancers. We also found that the identified BAD and CHCHD2 mutations frequently occur in melanoma but not in other cancers via The Cancer Genome Atlas analysis. Finally, we identified a frequent deletion of chr9q, encompassing PTCH1, and unreported frequent copy number gain of chr9p, encompassing the genes encoding the immune checkpoint ligands PD-L1 and PD-L2. In conclusion, this study is the first systematic analysis of coding and noncoding mutations in BCC and provides a strong basis for further analyses of the variants in BCC and cancer in general.

Evaluation of Hedgehog Pathway Inhibition on Nevoid Basal Cell Carcinoma Syndrome Fibroblasts and Basal Cell Carcinoma-Associated Fibroblasts: Are Vismodegib and Sonidegib Useful to Target Cancer-Prone Fibroblasts?

Activating mutations in the Hh pathway underlies the development of sporadic and familial skin BCC. For these oncogenic proliferations displaying ligand-independent activation of the intracellular pathway, two molecules have been approved for therapeutic purposes: vismodegib and sonidegib. Improper Hh signalling occurs in many human tumours also via a paracrine mechanism (ligand-dependent) in which the secretion of Hh ligands by stromal cells support tumour growth. On the other hand, the mobilization of neoplastic stroma by cancer cells is sustained by the activation of Hh signalling in surrounding fibroblasts suggesting a central role of this bidirectional crosstalk in carcinogenesis. Additionally, loss-of-function mutations in the PTCH1 gene in the context of NBCCS, an autosomal dominant disorder predisposing to multiple BCCs, determine tumour permissive phenotypes in dermal fibroblasts. Here, profiling syndromic and BCC-associated fibroblasts unveiled an extraordinary similarity characterized by overexpression of several Hh target genes and a marked pro-inflammatory outline. Both cell types exposed to Hh inhibitors displayed reversion of the tumour-prone phenotype. Under vismodegib and sonidegib treatment, the Wnt/β-catenin pathway, frequently over-active in tumour stroma, resulted down-regulated by pAKT-GSK3β axis and consequent increase of β-catenin turnover. Overall, this study demonstrated that vismodegib and sonidegib impacting on fibroblast tumour supportive functions might be considered in therapy for BCC independently to the mutation status of Hh components in neoplastic cells.

Expression and Significance of AQP3 in Cutaneous Lesions

Aquaporin 3 (AQP3) is the membrane channel of water and involved in fluid homeostasis. The aim of this study was to reveal the expression and significance of AQP3 in cutaneous lesions. We analyzed AQP3 mRNA levels using RT-PCR in 311 cutaneous lesions and confirmed AQP3 expression in these lesions by immunohistochemistry. AQP3 mRNA was detected in normal epidermis, seborrheic keratosis, solar keratosis, Bowen's disease, squamous cell carcinoma, eccrine poroma, apocrine carcinoma, and sebaceoma; however, AQP3 mRNA was absent in basal cell carcinoma, nevocellular nevus, or malignant melanoma. By immunohistochemistry, diffuse AQP3 expression was seen in all keratotic lesions including seborrheic keratosis, verruca vulgaris, molluscum contagiosum, solar keratosis, Bowen's disease, and squamous cell carcinoma. Diffuse AQP3 expression was also present in all extramammary Paget's disease. No AQP3 staining was obtained in basal cell carcinoma. Positive AQP3 staining was seen in sweat gland tumors including hidradenoma, eccrine poroma, and apocrine carcinoma. Among sebaceous tumors, AQP3 expressed diffusely in all sebaceous hyperplasia and sebaceous adenoma, but not in sebaceous carcinomas. Only focal AQP3 staining was seen in nevocellular nevus and no AQP3 staining in melanoma. Our findings indicate the function of AQP3 maintained in most skin tumors. AQP3 may be used for differential diagnosis in skin tumors.

Subtype-Specific Analyses Reveal Infiltrative Basal Cell Carcinomas Are Highly Interactive with their Environment

Little is known regarding the molecular differences between basal cell carcinoma (BCC) subtypes, despite clearly distinct phenotypes and clinical outcomes. In particular, infiltrative BCCs have poorer clinical outcomes in terms of response to therapy and propensity for dissemination. In this project, we aimed to use exome sequencing and RNA sequencing to identify somatic mutations and molecular pathways leading to infiltrative BCCs. Using whole-exome sequencing of 36 BCC samples (eight infiltrative) combined with previously reported exome data (58 samples), we determine that infiltrative BCCs do not contain a distinct somatic variant profile and carry classical UV-induced mutational signatures. RNA sequencing on both datasets revealed key differentially expressed genes, such as POSTN and WISP1, suggesting increased integrin and Wnt signaling. Immunostaining for periostin and WISP1 clearly distinguished infiltrative BCCs, and nuclear β-catenin staining patterns further validated the resulting increase in Wnt signaling in infiltrative BCCs. Of significant interest, in BCCs with mixed morphology, infiltrative areas expressed WISP1, whereas nodular areas did not, supporting a continuum between subtypes. In conclusion, infiltrative BCCs do not differ in their genomic alteration in terms of initiating mutations. They display a specific type of interaction with the extracellular matrix environment regulating Wnt signaling.

Metastatic and locally aggressive BCC: Current treatment options

The treatment of locally advanced and metastatic BCC presents a significant clinical challenge. Treatment options have evolved recently to include the use of hedgehog inhibitors Vismodigib and Sonidigib and immunotherapy with Cemiplimab.

Cell competition in intratumoral and tumor microenvironment interactions

Tumors are complex cellular and acellular environments within which cancer clones are under continuous selection pressures. Cancer cells are in a permanent mode of interaction and competition with each other as well as with the immediate microenvironment. In the course of these competitive interactions, cells share information regarding their general state of fitness, with less-fit cells being typically eliminated via apoptosis at the hands of those cells with greater cellular fitness. Competitive interactions involving exchange of cell fitness information have implications for tumor growth, metastasis, and therapy outcomes. Recent research has highlighted sophisticated pathways such as Flower, Hippo, Myc, and p53 signaling, which are employed by cancer cells and the surrounding microenvironment cells to achieve their evolutionary goals by means of cell competition mechanisms. In this review, we discuss these recent findings and explain their importance and role in evolution, growth, and treatment of cancer. We further consider potential physiological conditions, such as hypoxia and chemotherapy, that can function as selective pressures under which cell competition mechanisms may evolve differently or synergistically to confer oncogenic advantages to cancer.

Extensive Facial Trichoblastoma - A Rare and Disfiguring Condition

Patient: Female, 62-year-old

Final Diagnosis: Trichoblastoma

Symptoms: Nodular skin lesion • papular skin lesion

Medication: —

Clinical Procedure: —

Specialty: Dermatology • Family Medicine • Plastic Surgery

TERTp mutations and p53 expression in head and neck cutaneous basal cell carcinomas with different aggressive features

Cutaneous basal cell carcinoma (cBCC) is an economic burden to health services, due to its great morbidity and increasing incidence in old people. Infiltrative cBCCs and cBCCs with micronodular pattern are considered as more aggressive. The role of p53 expression and TERTp mutation on cBCC behavior remains to be clarified. We aimed to assess TERTp mutations and p53 expression in relation to the cBCC histological subtype in a cohort of patients referred to an ENT Department of a tertiary Hospital of Northern Portugal. We performed a retrospective clinicopathological and histological review of the head and neck cBCCs followed-up at the otorhinolaryngology department of Trás-os-Montes e Alto Douro hospital (January 2007–June 2018). We assessed TERTp mutations in 142 cBCCs and p53 protein expression, through immunohistochemistry, in 157 cBCCs. We detected TERTp mutations in 43.7% of cBCCs and p53 overexpression in 60.5% of cBCCs. We spotted association of p53 overexpression and TERTp mutation with necrosis. In the infitrative-growth pattern cBCCs, there was no significant association with the clinical and histological features evaluated, except for necrosis. In the indolent-growth cBCCs, we identified a significant association of TERTp mutation status with female sex, necrosis, multiple cBCCs, and p53 positive expression. Our results suggest that TERTp mutation may be useful to identify more aggressive features in the indolent-growth pattern cBCCs (nodular and superficial subtypes). Further studies with larger cohorts are warranted to clarify the relevance of TERTp mutation in cBCCs.

Deeply Supervised UNet for Semantic Segmentation to Assist Dermatopathological Assessment of Basal Cell Carcinoma

Accurate and fast assessment of resection margins is an essential part of a dermatopathologist's clinical routine. In this work, we successfully develop a deep learning method to assist the dermatopathologists by marking critical regions that have a high probability of exhibiting pathological features in whole slide images (WSI). We focus on detecting basal cell carcinoma (BCC) through semantic segmentation using several models based on the UNet architecture. The study includes 650 WSI with 3443 tissue sections in total. Two clinical dermatopathologists annotated the data, marking tumor tissues' exact location on 100 WSI. The rest of the data, with ground-truth sectionwise labels, are used to further validate and test the models. We analyze two different encoders for the first part of the UNet network and two additional training strategies: (a) deep supervision, (b) linear combination of decoder outputs, and obtain some interpretations about what the network's decoder does in each case. The best model achieves over 96%, accuracy, sensitivity, and specificity on the Test set.

The Impact of Notch Signaling for Carcinogenesis and Progression of Nonmelanoma Skin Cancer: Lessons Learned from Cancer Stem Cells, Tumor Angiogenesis, and Beyond

Since many decades, nonmelanoma skin cancer (NMSCs) is the most common malignancy worldwide. Basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) are the major types of NMSCs, representing approximately 70% and 25% of these neoplasias, respectively. Because of their continuously rising incidence rates, NMSCs represent a constantly increasing global challenge for healthcare, although they are in most cases nonlethal and curable (e.g., by surgery). While at present, carcinogenesis of NMSC is still not fully understood, the relevance of genetic and molecular alterations in several pathways, including evolutionary highly conserved Notch signaling, has now been shown convincingly. The Notch pathway, which was first developed during evolution in metazoans and that was first discovered in fruit flies (Drosophila melanogaster), governs cell fate decisions and many other fundamental processes that are of high relevance not only for embryonic development, but also for initiation, promotion, and progression of cancer. Choosing NMSC as a model, we give in this review a brief overview on the interaction of Notch signaling with important oncogenic and tumor suppressor pathways and on its role for several hallmarks of carcinogenesis and cancer progression, including the regulation of cancer stem cells, tumor angiogenesis, and senescence.