No abstract available

Basal cell nevus syndrome (BCNS) is an autosomal dominant skin disorder characterized by multiple basal cell nevi. Patients with BCNS tend to develop basal cell carcinoma (BCC) and frequently show skeletal abnormalities. Most cases of BCNS are caused by mutations in patched 1 (PTCH1). PTCH1 encodes a transmembrane receptor protein for the secreted molecule sonic hedgehog, which plays a key role in the development of animals ranging from insects to mammals. We analyzed two Japanese BCNS patients from two independent families. Both of our patients had multiple jaw keratocysts. In one patient, these were the key to noticing his BCNS, as he had no skin tumors. The early detection of PTCH1 mutations would enable BCNS patients to be carefully followed up for the occurrence of BCC. The diagnosis of BCC at the early stage leads to prompt surgical treatments, resulting in a good prognosis. The present cases suggest that keratocysts of the jaw might be an important clue for diagnosing BCNS.

Some patients with basal cell carcinoma develop a large number of basal cell carcinomas during their lives. The most common underlying genetic disease that causes multiple basal cell carcinomas is basal cell naevus syndrome. Basal cell naevus syndrome is caused by a germline mutation in patched-1 (PTCH1), a tumour suppressor gene of the hedgehog signalling pathway. However, in a significant portion of patients with multiple basal cell carcinomas, no underlying genetic cause is found. Nevertheless, these patients can experience a treatment burden comparable to that of patients with basal cell naevus syndrome. They are referred to as high-frequency basal cell carcinoma patients. Hedgehog pathway inhibitors were the first group of targeted therapy for basal cell carcinomas. This study reviews the literature on hedgehog pathway inhibitor therapy for patients with basal cell naevus syndrome and high-frequency basal cell carcinoma, to provide an overview on efficacy, safety, dosing regimens, tumour resistance and reoccurrence, and health-related quality of life.

Basal cell carcinomas (BCCs) are driven by abnormal hedgehog signaling and highly overexpress several hedgehog target genes. We report here our use of one of these target genes, hedgehog-interacting protein (Hip1), as a tumor-associated antigen for immunoprevention of BCCs in Ptch1+/- mice treated with ionizing radiation. Hip1 mRNA is expressed in adult mouse tissues at levels considerably lower than those in BCCs. Immunization with either of two large recombinant Hip1 polypeptides was well tolerated in Ptch1+/- mice, induced B and T cell responses detectable by enzyme-linked immunosorbent assay, Western blot, delayed type hypersensitivity, and enzyme-linked immunospot assay, and reduced the number of BCCs by 42% (P < 0.001) and 32% (P < 0.01), respectively. We conclude that immunization with proteins specifically up-regulated by hedgehog signaling may hold promise as a preventive option for patients such as those with the basal cell nevus syndrome who are destined to develop large numbers of BCCs.

Basal cell carcinoma can be misdiagnosed as acne; thus, carcinoma should be considered in treatment-resistant acne. Although rare, neglected basal cell carcinoma increases the risk of metastasis.

Basal cell nevus syndrome (also known as Gorlin Syndrome; MIM109400) is an autosomal dominant disorder characterized by recurrent pathological features such as basal cell carcinomas and odontogenic keratocysts as well as skeletal abnormalities. Most affected individuals have point mutations or small insertions or deletions within the PTCH1 gene on human chromosome 9, but there are some cases with more extensive deletion of the region, usually including the neighboring FANCC and/or ERCC6L2 genes. We report a 16-year-old patient with a deletion of approximately 400,000 bases which removes only PTCH1 and some non-coding RNA genes but leaves FANCC and ERCC6L2 intact. In spite of the small amount of DNA for which he is haploid, his phenotype is more extreme than many individuals with longer deletions in the region. This includes early presentation with a large number of basal cell nevi and other skin lesions, multiple jaw keratocysts, and macrosomia. We found that the deletion was in the paternal chromosome, in common with other macrosomia cases. Using public databases, we have examined possible interactions between sequences within and outside the deletion and speculate that a regulatory relationship exists with flanking genes, which is unbalanced by the deletion, resulting in abnormal activation or repression of the target genes and hence the severity of the phenotype.

Cytogenomic microarray (CMA) methodologies, including array comparative genomic hybridization (aCGH) and single-nucleotide polymorphism-detecting arrays (SNP-array), are recommended as the first-tier test for the evaluation of imbalances associated with intellectual disability, autism, and multiple congenital anomalies. The authors report on a child with global developmental delay (GDD) and a de novo interstitial 7.0 Mb deletion of 9q21.33q22.31 detected by aCGH. The patient that the authors report here is noteworthy in that she presented with GDD and her interstitial deletion is not inclusive of the 9q22.32 locus that includes the PTCH1 gene, which is implicated in Gorlin syndrome, or basal cell nevus syndrome (BCNS), has not been previously reported among patients with a similar or smaller size of the deletion in this locus suggesting that the genomic contents in the identified deletion on 9q21.33q22.31 is critical for the phenotype.

Basal cell nevus syndrome (BCNS, OMIM 109400) is a familial cancer syndrome characterized by the development of numerous basal cell cancers and various other developmental abnormalities, including epidermal cysts of the skin, calcified dural folds, keratocysts of the jaw, palmar and plantar pits, ovarian fibromas, medulloblastomas, lymphomesenteric cysts, and fetal rhabdomyomas. BCNS shows autosomal dominant inheritance and is caused by mutations in the patched 1 (PTCH1) gene and the suppressor of the fused homolog (SUFU) gene. In a few cases, variants of patched 2 (PTCH2) have been found in patients who met the criteria for BCNS. In an investigation of 11 Hungarian families who fulfilled the diagnostic criteria for BCNS, whole-exome sequencing (WES) and multiplex ligation-dependent probe amplification (MLPA) identified two novel pathogenic variants (c.2994C>A; p.Cys998Ter and c.814_818del; p.Asn272SerfsTer11), one recently identified variant (c.1737_1745del p.Val580_Val582del), and three recurrent disease-causing variants of the PTCH1 gene with a diagnosis rate of 63.6%. Disease-causing variants were not found for the SUFU and PTCH2 genes. These applied methods could not fully elucidate the genetic background of all the BCNS cases that we investigated. To uncover the missing heritability of BCNS, whole-genome sequencing or an epigenetic approach might be considered in the future.

Sonic hedgehog (SHH) signaling is essential for the differentiation and migration of early stem cell populations during cerebellar development. Dysregulation of SHH-signaling can result in cerebellar overgrowth and the formation of the brain tumor medulloblastoma. Treatment for medulloblastoma is extremely aggressive and patients suffer life-long side effects including behavioral deficits. Considering that other behavioral disorders including autism spectrum disorders, holoprosencephaly, and basal cell nevus syndrome are known to present with cerebellar abnormalities, it is proposed that some behavioral abnormalities could be inherent to the medulloblastoma sequalae rather than treatment. Using a haploinsufficient SHH receptor knockout mouse model (Ptch1+/-), a partner preference task was used to explore activity, social behavior and neuroanatomical changes resulting from dysregulated SHH signaling. Compared to wild-type, Ptch1+/- females displayed increased activity by traveling a greater distance in both open-field and partner preference tasks. Social behavior was also sex-specifically modified in Ptch1+/- females that interacted more with both novel and familiar animals in the partner preference task compared to same-sex wild-type controls. Haploinsufficiency of PTCH1 resulted in cerebellar overgrowth in lobules IV/V and IX of both sexes, and female-specific decreases in hippocampal size and isocortical layer thickness. Taken together, neuroanatomical changes related to deficient SHH signaling may alter social behavior.

Cutaneous adnexal tumours (ATs) encompass a variegated group of hamartomas and benign or malignant tumours, originating from the hair follicle, sebaceous, eccrine or apocrine glands that may simulate other cutaneous neoplasms. This study aims to provide a comprehensive overview of the spectrum of clinical and dermoscopic features of ATs, to better define these lesions and assist in the differential diagnosis. We performed a two-step systematic search of the literature in PubMed, Embase and Cochrane Library databases from inception until 4 September 2020. In the first step, we aimed to define histological variants of ATs with descriptions of dermoscopic criteria. The second step included a search for the name of each previously identified AT variants in the same databases adding 'AND (epilum* or dermosc* or dermatosc*)'. All study types in English language reporting dermoscopic images of ATs were included. Collisions between ATs and other inflammatory or neoplastic skin lesions were excluded, with the exception of collisions with a sebaceous nevus. The protocol of this study was prospectively registered in PROSPERO (CRD42021244677). In total, 206 articles met our inclusion criteria, encompassing 372 ATs in 365 patients. Most ATs were apocrine-eccrine (n = 217, 58.3%, n = 173 benign) with a prevalence of poromas (n = 82), followed by follicular ATs (n = 88, 23.7%, n = 83 benign) and sebaceous ATs (n = 67, 18.0%, n = 49 benign). Most patients had a single AT lesion (320, 86.0%), while 42 (11.3%) had multiple ATs. A syndrome causing multiple ATs was identified in 15 patients. Histopathological analysis revealed 82% benign (n = 305) and 18.0% malignant (n = 67). ATs were classified according to their ability to mimic four groups of more common skin tumours: basal cell carcinoma, squamous cell carcinoma, melanocytic lesions and benign cutaneous lesions. Moreover, we have highlighted the ability of malignant variants of ATs to simulate benign skin lesions. This systematic review offers a comprehensive overview of the common clinical and dermoscopic features of follicular, sebaceous and apocrine-eccrine ATs and details possible differential dermoscopic features.