Metastatic Basal Cell Carcinoma

Personalized treatment concepts in extraocular cancer

Background

The periocular skin is neoplasms-prone to various benign and malignant. Periocular malignancies are more aggressive and challenging to cure and repair than those in other skin areas. In recent decades, immunotherapy has significantly advanced oncology, allowing the autoimmune system to target and destroy malignant cells. Skin malignancies, especially periocular tumors, are particularly sensitive to immunotherapy. This technique has dramatically impacted the successful treatment of challenging tumors.

Main text

Extraocular cancers, including eyelid (basal cell carcinoma, squamous cell carcinoma, melanoma, merkel cell carcinoma), conjunctival tumors (conjunctival melanoma, ocular surface squamous neoplasia) and other rare tumors, are unique and challenging clinical situations. Several genetic alterations associated with the pathogenesis of these diseases have been identified, and molecular mechanism are essential for the development of the immunotherapy agents, such as Hedgehog pathway inhibitors (vismodegib and sonidegib) for basal cell carcinoma, BRAF/MEK inhibitors (vemurafenib, dabrafenib, and encorafenib) for melanoma, and immune checkpoint inhibitors (Avelumab, pembrolizumab) for Merkel cell carcinoma.

Conclusions

The optimal treatment for periocular skin cancer depends on the type and size of the tumor and whether it involves orbital and adnexal structures. Adjuvant and neoadjuvant therapy with chemotherapy-targeted therapies and immune checkpoint inhibitors should be considered based on tumor type, tumor molecular profile, expected response rate, and candidacy for systemic treatment.

The top 100 most cited articles in the treatment of basal cell carcinoma over the last decade: A bibliometric analysis and review

Basal cell carcinoma (BCC) represents the most prevalent cancer globally. The past decade has witnessed significant advancements in BCC treatment, primarily through bibliometric studies. Aiming to perform a comprehensive bibliometric analysis of BCC treatments to comprehend the research landscape and identify trends within this domain, a dataset comprising 100 scientific publications from the Web of Science Core Collection was analyzed. Country co-operation, journal co-citation, theme bursts, keyword co-occurrence, author co-operation, literature co-citation, and field-specific references were examined using VOSviewer and CiteSpace visualization tools. These articles, published between 2013 and 2020, originated predominantly from 30 countries/regions and 159 institutions, with the USA and Germany at the forefront, involving a total of 1118 authors. The keyword analysis revealed significant emphasis on the hedgehog pathway, Mohs micrographic surgery, and photodynamic therapy. The research shows developed nations are at the forefront in advancing BCC therapies, with significant focus on drugs targeting the hedgehog pathway. This treatment avenue has emerged as a crucial area, meriting considerable attention in BCC therapeutic strategies.

Fluorescence spectral analysis and logistic regression modeling for diagnosing basal cell carcinoma on head and neck

The optical fluorescence method is distinguished by key features such as non-invasiveness, high sensitivity, and resolution, which are superior to traditional diagnostic approaches. Unlike histopathological examinations and biochemical analyses, optical diagnostic methods obviate the need for tissue sampling, enabling the analysis of virtually unlimited material. The research aims to examine the effectiveness of emission spectra analysis in the diagnosis of basal cell carcinoma (BCC) of the scalp and neck. The analysis was based on data provided by Specialized Hospital No. 2 in Bytom comprising a study sample of 10 patients. For each patient, fluorescence emission spectra were recorded from each of 512 points along a 5 mm line. The results obtained from the histopathological examination, the analysis and morphological evaluation of the tissue, and the diagnosis through microscopic observation were used to define a dichotomous variable (presence or absence of a cancerous lesion), adopted in the study as the modeled variable. The next step of the presented study involved constructing a logistic regression model for identifying cancerous lesions depending on the biochemical indicator's relative fluorescence value (RFV) and emission wavelength (ELW) within the 620 nm to 730 nm range. This wavelength range is often used in fluorescence diagnostics to detect various pathologies, including cancerous lesions. The resulting binary logistic regression model, logit(p)=-33.17+0.04ELW+0.01RFV, indicates a statistically significant relationship between wavelength and relative fluorescence values with the probability of detecting cancer. The estimated model exhibits a good fit and high predictive accuracy. The overall model accuracy is 84.8 %, with the correct classification rates at approximately 96 % for healthy individuals and 74 % for individuals with cancer. These findings underscore the potential of photodynamic diagnostics in cancer detection and monitoring.

Utility of GLI1 RNA Chromogenic in Situ Hybridization in Distinguishing Basal Cell Carcinoma From Histopathologic Mimics

Basal cell carcinoma (BCC) is the most common human malignancy and is a leading cause of nonmelanoma skin cancer-related morbidity. BCC has several histologic mimics which may have treatment and prognostic implications. Furthermore, BCC may show alternative differentiation toward a variety of cutaneous structures. The vast majority of BCCs harbor mutations in the hedgehog signaling pathway, resulting in increased expression of the GLI family of transcription factors. GLI1 immunohistochemistry has been shown to discriminate between several tumor types but demonstrates high background signal and lack of specificity. In this study, we evaluated the utility of GLI1 RNA chromogenic in situ hybridization (CISH) as a novel method of distinguishing between BCC and other epithelial neoplasms. Expression of GLI1 by RNA CISH was retrospectively evaluated in a total of 220 cases, including 60 BCCs, 37 squamous cell carcinomas (SCCs) including conventional, basaloid, and human papillomavirus infection (HPV)-associated tumors, 16 sebaceous neoplasms, 10 Merkel cell carcinomas, 58 benign follicular tumors, and 39 ductal tumors. The threshold for positivity was determined to be greater than or equal to 3 GLI1 signals in at least 50% of tumor cells. Positive GLI1 expression was identified in 57/60 BCCs, including metastatic BCC, collision lesions with SCC, and BCCs with squamous, ductal, or clear cell differentiation or with other unusual features compared to 1/37 SCCs, 0/11 sebaceous carcinomas, 0/5 sebaceomas, 1/10 Merkel cell carcinomas, 0/39 ductal tumors, and 28/58 follicular tumors. With careful evaluation, GLI1 RNA CISH is highly sensitive (95%) and specific (98%) in distinguishing between BCC and nonfollicular epithelial neoplasms. However, GLI1 CISH is not specific for distinguishing BCC from most benign follicular tumors. Overall, detection of GLI1 RNA by CISH may be a useful tool for precise classification of histologically challenging basaloid tumors, particularly in the setting of small biopsy specimens, metaplastic differentiation, or metastatic disease.

Immunotherapy and Its Timing in Advanced Basal Cell Carcinoma Treatment

For patients with advanced basal cell carcinoma (BCC), including locally advanced or metastatic BCC not amenable to curative surgery or radiotherapy, hedgehog pathway inhibitors (HHI) vismodegib and sonidegib are approved as first-line systemic treatment. Results from clinical trials highlight that the overall discontinuation rate of HHI treatment varies from 88% to 92% with vismodegib and is approximately 92% with sonidegib, and half of patients will discontinue HHI after approximately 8 to 12 months. The main factors weighing in on the decision to discontinue HHI include efficacy (tumor response), adverse events and patient decision. In clinical practice, some of the patients that stop HHI may be re-evaluated if the tumor becomes amenable to surgery, or restart HHI at a later time, while others will need to switch to immunotherapy, depending on the reasons for HHI discontinuation. In this review, we revisit the therapeutic decisions considering a switch from HHI to immunotherapy with anti-PD-1 agent cemiplimab and we highlight the place of cemiplimab in the therapeutic ladder for patients with advanced BCC. We discuss the evidence on the efficacy and safety of anti-PD-1 agents as second-line systemic monotherapy, or in combination with other treatments, and the emergence of checkpoint immunotherapy as a neoadjuvant treatment.

Statical Association between Clinical and Histopathological Parameters for Keratinocyte Carcinomas

The most common tumor of the western world is comprised of forms of non-melanoma skin cancers, previously known as keratinocyte carcinomas (KCs) The purpose of this study was to determine de incidence of non-melanoma skin tumors and the relationship between histopathological risk factors in patients with skin cancers. The study was composed from 332 cases of skin malignancies for which clinical and histopathological aggressivity factors were statistically analyzed through comparison tests and also stored digitally. For basal cell carcinoma (BCC) statistical analysis indicated significant relationships between pT category and gender, tumor size, ulceration, depth of invasion and positive resection limits. For squamous cell carcinoma (SCC) statistical analysis indicated significant relationships between pT category and tumor size, depth of invasion and positive resection limits. Clinical and histological analysis of certain characteristics of the above-mentioned skin cancers is an essential step in documenting and improving both prognosis and therapy standards.

Metastatic basal cell skin cancer with distant metastatic skeletal lesions: a clinical case report

Clinical cases of distant metastasis of basal cell skin cancer are extremely rarely described in the international publications. This is probably due to the specific locally advanced growth of this histological type of tumor, as well as to the improvement of radical treatment methods for this group of patients. However, despite the development of both diagnostic research methods and treatment tactics, a large number of patients, especially when the primary tumor is located on the face and neck region, choose less effective and not always radical methods of treatment. In turn, non-radical removal of the primary tumor leads not only to difficulties in local control of the disease, but also to lymphogenous, as well as hematogenous spread of tumor cells and the manifestation of systemic metastasis.

In the article, we present a clinical case of metastatic basal cell skin carcinoma of the periorbital region with lesions of the bones of the skeleton, namely the thoracic vertebrae manifested 11 years after the detection of the primary tumor.

Genomic Profiling of Metastatic Basal cell Carcinoma Reveals Candidate Drivers of Disease and Therapeutic Targets

Basal cell carcinomas (BCCs) are human beings' most common malignant tumors. Most are easily managed by surgery or topical therapies, and metastasis is rare. Although BCCs can become locally advanced, metastatic BCCs are very uncommon and may be biologically distinct. We assessed the clinicopathologic characteristics of 17 patients with metastatic BCC and pursued whole-exome sequencing of tumor and germline DNA from 8 patients. Genomic profiling revealed aberrant activation of Hedgehog signaling and alterations in GLI transcriptional regulators and Notch and Hippo signaling. Matched local recurrences of primary BCCs and metastases from 3 patients provided evidence of a clonal origin in all cases. Mutations associated with YAP inhibition were found exclusively in 2 hematogenously-spread lung metastases, and metastatic BCCs were enriched for mutations in the YAP/TAZ-binding domain of TEAD genes. Accordingly, YAP/TAZ nuclear localization was associated with metastatic types and Hippo mutations, suggesting an enhanced oncogenic role in hematogenously-spread metastases. Mutations in RET, HGF, and phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (AKT) signaling were enriched compared with a cohort of low clinical-risk BCCs. Our results implicate Hippo and PI3K/AKT dysregulation in metastatic progression of BCCs, making these potential therapeutic targets in metastatic disease. The common clonal origin of matched recurrent and metastatic BCCs suggests that molecular profiling can assist in determining the nature/origin of poorly differentiated metastatic tumors of uncertain type. Genes and pathways enriched for mutations in this cohort are candidate drivers of metastasis and can be used to identify patients at high risk of metastasis who may benefit from aggressive local treatment and careful clinical follow-up.

Neuropathic upper extremity pain: A double-crush scenario

ABSTRACT

Neuropathic upper extremity pain has many causes. Cubital tunnel syndrome is the second most common compressive peripheral neuropathy after carpal tunnel syndrome. Entrapment, or compression, of the ulnar nerve at the elbow classically presents with elbow pain, numbness in the ulnar nerve distribution, and weakness in the hand. C8 radiculopathy and various brachial plexopathies can mimic cubital and carpal tunnel syndromes. Neoplastic brachial plexopathy typically is caused by local extension of a primary or metastatic tumor into the brachial plexus. Double-crush syndrome further complicates neuropathic upper extremity pain. This case report describes a patient with a double-crush lesion involving the ulnar nerve at the elbow and a metastatic mass involving the lower trunk of the brachial plexus. Because of overlapping symptoms and presentations of several upper extremity nerve conditions, clinicians must perform a thorough history and physical examination and understand the sensory and motor innervation of the upper extremity to arrive at a timely and accurate diagnosis.

The Relationship between Vitamin D and Basal Cell Carcinoma: A Systematic Review

This systematic review studies the relationship between vitamin D serum levels and basal cell carcinoma (BCC). The primary source of vitamin D is sunlight exposure. Recently, an increase in the intake of vitamin D supplements has been noticed. The protective value of vitamin D is well established and has been studied several times for the health of the bones, cartilage, growth, various dermatological diseases, and also as a chemoprotective agent against several cancers. On the scientific front, it has yet to be established that increasing serum vitamin D levels increase the incidence of BCC. We included reports that investigated this relationship in this review. We applied keywords in published papers in PubMed, ScienceDirect, Cochrane, and Google Scholar to find relevant studies. After applying the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist and the quality appraisal for 68 records, we included only ten studies. In these studies, serum levels of vitamin D were measured. Five of them supported the link between BCC incidence and development and high serum vitamin D levels (e.g., Mahamat-Saleh Y, et al.), while the other five did not (e.g., Tang JY, et al.). We included only two studies that investigated the vitamin D receptor (VDR) polymorphism. Experts debate adding a high dose of vitamin D supplements to our daily routine. After studying most of the reports, it was ascertained that the literature supports keeping vitamin D serum levels below 30-60 nmol/L. However, further studies should be done to help find a healthy balance of vitamin D serum levels, especially when it comes to increasing the risk of cancer like BCC.

Cytokeratin 10 (CK10) expression in cancer: A tissue microarray study on 11,021 tumors

Cytokeratin 10 (CK10) is a type I acidic low molecular weight cytokeratin which is mainly expressed in keratinizing squamous epithelium of the skin. Variable levels of CK10 protein have been described in squamous carcinomas of different sites and in some other epithelial neoplasms. To comprehensively determine the prevalence of CK10 expression in normal and neoplastic tissues, a tissue microarray containing 11,021 samples from 131 different tumor types and subtypes was analyzed by immunohistochemistry. CK10 immunostaining was detectable in 41 (31.3 %) of 131 tumor categories, including 18 (13.7 %) tumor types with at least one strongly positive case. The highest rate of positive staining was found in squamous cell carcinomas from various sites of origin (positive in 18.6 %-66.1 %) and in Warthin tumors of salivary glands (47.8 %), followed by various tumor entities known to potentially exhibit areas with squamous cell differentiation such as teratomas (33.3 %), basal cell carcinomas of the skin (14.3 %), adenosquamous carcinomas of the cervix (11.1 %), and several categories of urothelial neoplasms (3.1 %-16.8 %). In a combined analysis of 956 squamous cell carcinomas from 11 different sites of origin, reduced CK10 staining was linked to high grade (p < 0.0001) and advanced stage (p = 0.0015) but unrelated to HPV infection. However, CK10 staining was not statistically related to grade (p = 0.1509) and recurrence-free (p = 0.5247) or overall survival (p = 0.5082) in 176 cervical squamous cell carcinomas. In the urinary bladder, CK10 staining occurred more commonly in muscle-invasive (17.7 %) than in non-invasive urothelial carcinomas (4.0 %-6.0 %; p < 0.0001). In summary, our data corroborate a role of CK10 as a suitable marker for mature, keratinizing squamous cell differentiation in epithelial tissues. CK10 immunohistochemistry may thus be instrumental for a more objective evaluation of the clinical significance of focal squamous differentiation in cancer.

A Rare Case of Neglected Giant Basal Cell Carcinoma in a Nurse-Case Report and Literature Review

Basal cell carcinoma (BCC) is the most common skin cancer in the fair-skinned adult population over 50 years of age and the incidence is rising. Generally, BCC has an indolent course, low mortality and a good prognosis due to low rates of metastasis. Giant basal cell carcinoma is a rare reported oncological entity which accounts for 0.5% to 1% of all cases of BCC and has a diameter larger than 5cm. Basosquamous carcinoma is a rare high-risk type of BCC with clinical and histopathological features of both BCC and squamous cell carcinoma. A 61-year-old female presented to our clinic for a giant bleeding tumor located under her left breast. She initially noted the tumor almost 15 years ago. Although the patient was a nurse, she was afraid to seek medical advice until an episode of significant bleeding. At presentation the tumor was a 15/7cm in size, was invading the underlying structures and had a central ulceration. The margins of the tumoral plaque had several nodules and pearly structures suggesting the possible clinical diagnosis of BCC.

Basosquamous Basal Cell Carcinoma with Bone Marrow Metastasis

Basal cell carcinoma (BCC) is the most common cancer in Caucasians. It is slow growing and rarely metastasizes. If left untreated over time, invasive growth can occur. We present a patient case with a primary BCC located in the right sub-mammary area, with extensive metastases to the skeleton and bone marrow. Histopathological examination of the tumour showed BCC with a diverse growth pattern. There were no signs of local metastases. Surgery was successfully performed. Three months post-surgery the patient developed normocytic anaemia and elevated inflammation markers. [18F]FDG PET/CT showed extensive FDG uptake in the entire skeleton and bone marrow. Biopsy confirmed the infiltration of BCC with similar histopathological features as the primary tumour. Prognosis of metastasized BCC is poor and, therefore, long-term follow-up of patients with risk factors is of importance.

A Case of Metastatic Basal Cell Carcinoma (BCC) With Spinal and Pulmonary Metastases Treated With Vismodegib, Sonedigib, and Radiotherapy

Basal cell carcinoma (BCC) is the most common malignancy worldwide and has one of the most favorable prognoses due to its tendency to remain local. Clinical presentation with rare distant metastases significantly increases morbidity and mortality. Historically, no effective therapies have existed for locally advanced or metastatic BCC. Recent research highlights the possibility of treating patients with advanced and metastatic BCC with hedgehog pathway inhibitors, such as vismodegib or sonedigib. We present the case of a 62-year-old male with a history of a large left shoulder lesion, which was diagnosed as a nodulocystic BCC following biopsy and histopathologic examination. The primary lesion was managed with surgical excision, and his ensuing metastatic disease was treated with vismodegib, sonedigib, tumor debulking, and radiation therapy. Magnetic resonance imaging and computed tomography of the chest revealed probable metastases to the apical segment of the left upper lobe and thoracic spine, leading to spinal stenosis and probable cause of the patient's ataxia and paresthesias. Due to the ability of BCCs to transform during metastasis, it is impossible to identify the nature of metastatic lesions (i.e., basaloid, squamous, or hybrid) without biopsy. In this case report, we review the etiologies, typical demographics, presentation patterns, and treatment regimens for metastatic BCC and the possibility of metastatic disease transforming to squamous or hybrid variants.

Neglected cutaneous skin malignancy: A patient with concurrent giant basal cell carcinoma and melanoma

Background

Giant basal cell carcinomas (BCCs) are a rare subtype of BCC that grow to be greater than 5 cm in diameter. With the increase in size, there is a corresponding increase in metastatic rate and state of local invasion, with a clinical morphology that can be hard to differentiate from other subtypes of cutaneous malignancy. Although histologically equivalent to their common sub‐centimetre counterparts, giant BCCs can precipitate significant systematic medical morbidity as well as psychological trauma, and can be a real surgical reconstructive challenge to clinicians.

Aims

To add breadth to the existing cases in the literature, as well as a fresh patient perspective on the psychological challenges in a patient with Giant BCC.

Materials & Methods

A case from the Waikato Hospital, New Zealand referred to the Plastic and Reconstructive Department is carefully photographed, ordered, and presented.

Results

We present a case of a 15 cm giant BCC of the back existing alongside a neglected thick exophytic melanoma of the elbow in a patient who had been too embarrassed to approach healthcare professionals. These skin lesions were an incidental discovery by the general practitioner after the patient presented with symptoms of shortness of breath.

Discussion

Neglected skin cancers can fungate and be clinically morphologically confusing. Photographs of examples of these tumours can hone clinician awareness of the existance of Giant BCCs.

Conclusion

Giant BCCs are an entity yet to receive standardized treatment stratification. Prompt diagnosis and staging scans mean an expedited path to wide local excision and reconstruction, resulting in timely resolution of patients' immediate morbidity from their oncological disease burden.

Metastasizing basal cell carcinoma: A clinicopathologic and immunohistochemical study of 22 cases

Basal cell carcinomas metastasize rarely, and there have been limited studies of potential drivers for this metastasis. Epithelial-mesenchymal transition (EMT) may play a role, although this has not been investigated in detail. We reviewed clinicopathologic features of 22 patients with metastasizing basal cell carcinoma (MBCC). Immunohistochemical markers of EMT, including CD44, E-cadherin, claudin, smooth muscle actin, beta-catenin, Twist1, and Oct 3/4, were evaluated on 10 MBCC (primary and metastases) and 18 non-metastasizing BCC. Primary sites included the head and neck, trunk, and extremity, while metastatic sites included lymph nodes, lung, bone, and soft tissue. Of 19 cases with follow-up, the range of follow-up after diagnosis of metastasis was 5 to 248 months (median: 50 months). Two cases were of unknown primary, nine metastases were diagnosed concurrently with primary tumors, and remaining cases showed a median latency between diagnosis of primary and metastatic tumors of 27.5 months (range: 3-81 months). Median survival was 66 months. Compared to non-metastasizing BCC, MBCC demonstrated reduced CD44 expression (primary [P = .0036], metastatic [P = .011]) and increased Twist1 expression (primary, P = .0017). MBCC shows variably aggressive behavior, and reduced CD44 and increased Twist1 expression may indicate significant EMT in metastasizing tumors and signify a metastatic phenotype.

Metastatic basal cell carcinoma with atypical pattern of spread

Basal cell carcinoma is the most common malignancy in the United States. However, metastasis of basal cell carcinoma is exceedingly rare, with incidence estimates of 0.0028-0.055%. When it does metastasize, basal cell carcinoma most commonly spreads to regional lymph nodes and lungs, although other sites of disease can occur. This case report presents multi-modality imaging of a 54-year-old male who developed multifocal metastatic basal cell carcinoma approximately three years after initial presentation with an ulcerated groin lesion. Ultimately, metastases included many common and uncommon sites, including lymph nodes, lung, duodenum, spleen, and adrenal glands. This case provides an interesting example of an uncommon pattern of spread and associated symptoms of treatment-resistant metastatic basal cell carcinoma.

Metastatic Basal Cell Carcinoma of the Skin: A Comprehensive Literature Review, Including Advances in Molecular Therapeutics

Basal cell carcinoma (BCC) of the skin is the most common type of malignant human tumor. In Europe, the incidence of BCC ranges from 44.6 to 128 cases per 100,000 inhabitants annually, whereas in the United States, the yearly incidence rate ranges between 500 and 1500. The global incidence has been calculated to be as high as 10 million cases of BCC per year. There are 2 main clinical patterns of BCC-the familial BCC in basal cell nevus syndrome and sporadic BCC. The etiology of cutaneous BCC is usually the result of the interaction between solar ultraviolet radiation and genetic factors. Somatic or germline mutations in the effector components of the hedgehog signaling pathway (ie, PTCH1, PTCH2, SMO or SUFU genes) are responsible for ∼90% of the cases of both sporadic and familial BCC, all causing a constitutive activation of the hedgehog pathway. Cutaneous BCC very rarely metastasizes, and diagnosis in metastatic sites can be very difficult. Metastatic BCC has weakly effective therapeutic options with a poor prognosis until few years ago. In 2012, small-molecule therapies, involving inactivation of the hedgehog signaling pathway, and capable of reducing tumor growth and progression have been introduced into clinical practice for advanced (locally advanced or metastatic) BCC. We performed a comprehensive literature review on metastatic BCC and found at least 915 cases reported to date. In addition, we extensively discussed the differential diagnosis of metastatic BCC, and outlined the advances in clinical therapeutics involving these small molecules.

Erosive rodent ulcer of the ear secondary to neglect

Basal cell carcinomas (BCCs) are slow-growing, locally invasive lesions that rarely metastasise, however, if left untreated can progress to extensive destruction of local structures giving rise to the alternative name 'the rodent ulcer'. Here we present a case of BCC of the ear progressing to destruction of the pinna and mastoid, involving the facial nerve and breaching dura. This case presentation shows not only the seldom-seen natural progression of the rodent ulcer with impressive imaging and clinical photographs but also highlights a broader topic of capacity and consent in patients displaying maladaptive denial or abnormal illness behaviour, how this can affect patient outcomes and what we as clinicians can do to ensure the best care for our patients.

Hedgehog Pathway Alterations Downstream of Patched-1 Are Common in Infundibulocystic Basal Cell Carcinoma

ABSTRACT

The infundibulocystic variant of basal cell carcinoma (BCC) is characterized histologically by anastamosing strands of basaloid epithelium with associated small infundibular-type cysts. Since its first description in 1987, this rare entity has generated considerable controversy with some authors classifying it as a benign follicular neoplasm rather than a BCC subtype. Prior studies aiming to settle this issue using immunohistochemical analysis reached opposite conclusions. The defining feature of BCC is activation of the Hedgehog signaling pathway, and mutations in Patched-1 (PTCH1) are the most common molecular finding in both sporadic and inherited forms of BCC. Mutations in other downstream components including Smoothened (SMO) and Suppressor of Fused (SUFU) also occur, but are much less common. Here, we report a molecular genetic analysis of a small series of infundibulocystic BCC using a next-generation DNA sequencing platform. All 4 cases harbored mutations or other genetic alterations in components of the Hedgehog pathway, supporting the classification of this entity as a BCC variant. Interestingly, these tumors were enriched for genetic alterations downstream of PTCH1, involving SUFU, SMO, GLI1, and GLI2. This observation was of particular interest given that rare kindreds of the Multiple Hereditary Infundibulocystic BCC syndrome (MHIBCC), which is related, but possibly distinct from the nevoid BCC syndrome, harbored mutations in SUFU. Our results support the classification of the infundibulocystic variant as a subtype of BCC, and suggest that the level at which genetic alterations occur within the Hedgehog pathway may be an important determinant of the morphologic features in BCC.

The Pathobiology of Skin Aging: New Insights into an Old Dilemma

Long considered both physiologic and inevitable, skin aging is a degenerative phenomenon whereby both intrinsic and environmental factors conspire to produce an authentic disease. The consequences of this disorder are many and varied, ranging from atrophy and fragility to defective repair to deficient immunity and vulnerability to certain infections. The pathobiologic basis for skin aging remains poorly understood. At a cellular level, stem cell dysfunction and attrition appear to be key events, and both genetic and epigenetic factors are involved in a complex interplay that over time results in deterioration of our main protective interface with the external environment. Past and current understanding of the cellular and molecular intricacies of skin aging provide a foundation for future approaches designed to thwart the aging phenotype. Herein, the authors provide a review of current insights into skin aging, including the mechanisms of skin aging, the role of stem cells in skin aging and the implications of skin aging for the microbiome and for the development of cancer. Conquest of the oft overlooked disease of skin aging should have broad implications that transcend the integument and inform novel approaches to retarding aging and age-related dysfunction in those internal organs that youthful skin was designed to envelop and safeguard.

Metastatic Cutaneous Basal Cell Carcinoma: Report of 2 Cases Preceding the Hedgehog Pathway Antagonists Era

Basal cell carcinoma (BCC) of the skin is the most common type of malignant human tumor. However, metastatic BCC is a very rare event with weakly effective therapeutic options and a poor prognosis, until a few years ago. In 2012, small-molecule therapies, capable of inactivating the hedgehog signaling pathway and thus reducing tumor growth and progression, were introduced into clinical practice for the treatment of patients with advanced BCC. We present retrospectively 2 personal cases of metastatic BCC of the skin, from the premolecular therapy era, from primary tumors that arose years before in the head and neck area. The former case occurred in a 45-year-old woman with a history of recurrent BCC of the retroauricular skin who eventually died due to diffuse metastatic spread. The latter case concerned a 70-year-old man also with a history of recurrent BCC of the nasal-perinasal skin who developed multiple subcutaneous and lymph node metastases in the neck. In both cases, the diagnoses were based on biopsies of the metastatic sites. The first patient died 5 months after the diagnosis of metastatic disease, while the second was alive and disease-free 2 years after neck lymph node dissection and external radiation therapy, and then lost to follow-up. We extensively discuss several tumor entities with basal or basaloid features that may enter the differential diagnosis with BCC in metastatic sites. In addition, we briefly summarize the advances in clinical therapeutics using small molecules, which are now an integral part of the treatment of such advanced BCC cases.

Molecular testing in metastatic basal cell carcinoma

BACKGROUND

Metastatic basal cell carcinoma (mBCC) is a very rare entity, and diagnosis can be challenging. Therapeutic options are limited, and response to targeted therapy is poor.

OBJECTIVE

To demonstrate a clonal relationship between BCCs and their metastases and to explore which hedgehog pathway-related mutations are involved in mBCC.

METHODS

Genetic analysis was conducted in 10 primary BCCs and their metastases. Genes relevant for BCC development were analyzed in tumor and metastasis material with small molecule molecular inversion probes (smMIPs) for PTCH1, PTCH2, SMO, SUFU, GLI2, and TP53 or with targeted next generation sequencing of the same genes and CDKN2A, CDKN2B, CIC, DAXX, DDX3X, FUBP1, NF1, NF2, PTEN, SETD2, TRAF7, and the TERT promoter.

RESULTS

In 8 of 10 patients, identical gene mutations could be demonstrated in the primary tumors and their metastases. A broad spectrum of mutations was found. Four patients had SMO mutations in their tumor or metastasis, or both. All SMO mutations found were known to cause resistance to targeted therapy with vismodegib.

LIMITATIONS

In 2 patients there was insufficient qualitative DNA available for genetic analysis.

CONCLUSIONS

Molecular testing can help to identify the origin of a BCC metastasis and may be of prognostic and therapeutic value.