Brooke-Spiegler Syndrome: Report of 10 Patients From 8 Families With Novel Germline Mutations: Evidence of Diverse Somatic Mutations in the Same Patient Regardless of Tumor Type

Trichoblastoma: A Consecutive Series of 349 Sporadic Cases Analyzed by Ackerman Subtypes

ABSTRACT

Trichoblastoma (TB) is a benign biphasic follicular neoplasm with differentiation toward the germinative cells and a specific follicular mesenchyme. We subtyped 349 sporadic TB according to a classification proposed by Ackerman. Two hundred forty-six (246/349, 70.5%) neoplasms were comprised of mixed subtypes. TB composed exclusively of a single pattern was less common (103/349, 29.5%). The most common pure subtype was cribriform TB followed by small nodular TB. Twelve cases (12/349, 3.4%) had unique features and are reported herein as novel histopathologic subtypes of the neoplasm.

Genetic Testing in CYLD Cutaneous Syndrome: An Update

CYLD cutaneous syndrome (CCS) is an inclusive label for the inherited skin adnexal tumour syndromes Brooke–Spiegler Syndrome (BSS-OMIM 605041), familial cylindromatosis (FC – OMIM 132700) and multiple familial trichoepitheliomas (MFT-OMIM 601606). All three syndromes arise due to germline pathogenic variants in CYLD, a tumour suppressor gene (OMIM 605018). CCS is transmitted in an autosomal dominant pattern, and has variable expressivity, both of the three syndromic phenotypes, and of the severity of tumour burden. Age-related penetrance figures are not precisely reported. The first tumours typically appear during puberty and progressively accumulate through adulthood. Penetrance is typically high, with equal numbers of males and females affected. Genetic testing is important for confirmation of the clinical diagnosis, genetic counselling and family planning, including preimplantation diagnosis. Additionally, identified CCS patients may be eligible for future clinical trials of non-surgical pre-emptive interventions that aim to prevent tumour growth. In this update, we review the clinical presentations of germline and mosaic CCS. An overview of the germline pathogenic variant spectrum of patients with CCS reveals more than 100 single nucleotide variants and small insertions and deletions in coding exons, most frequently resulting in predicted truncation. In addition, a minority of patients have large deletions involving the CYLD gene, intronic pathogenic variants that affect splicing, or inversions. We discuss germline and somatic testing approaches. Somatic testing of tumour tissue, relevant in mosaic CCS, can reveal recurrently detected pathogenic variants when two or more tumours are tested. This can influence genetic testing of children, who may inherit this as a germline variant, and inform genetic counselling and prenatal diagnosis. Finally, we discuss testing technologies that are currently used, their benefits and limitations, and future directions for genetic testing in CCS.

Observations on Four Cases of Brooke–Spiegler Syndrome

Background: Brooke–Spiegler Syndrome is a rare genetic autosomal dominant disorder with variable penetrance. Its main feature consists of the development of multiple adnexal tumors that originate from the follicular-sebaceous-apocrine unit, most commonly: cylindromas, trichoepitheliomas and spiradenomas. Case presentation: We present four cases of Brooke–Spiegler Syndrome found in our clinic, as well as their clinicopathological traits and the surgical techniques used in their management. The familial history of three of the presented cases supports the genetic component of the disease. Cylindromas, spiradenomas and trichoepitheliomas coexisted in one of the cases presented. The therapeutic options used were electrocautery, CO2 laser, as well as tumor debulking followed by closure with metal staples. Discussion: The treatment remains a challenge and must be individualized based on the type, location and number of the lesions. Conservative methods such as CO2 laser and tumor debulking accompanied by closure with metal staples remain a viable option taking into account the large number of lesions. As patients usually develop multiple neoplasms throughout their lifetime, repeated procedures may be needed. Conclusion: Considering the few numbers of Brooke–Spiegler syndrome cases in the current literature, the authors report these patients in order to increase awareness and to help establish the most appropriate approach in managing the disease.

The E3 ubiquitin ligase MIB2 enhances inflammation by degrading the deubiquitinating enzyme CYLD

The tumor suppressor CYLD is a deubiquitinating enzyme that suppresses polyubiquitin-dependent signaling pathways, including the proinflammatory and cell growth-promoting NF-κB pathway. Missense mutations in the CYLD gene are present in individuals with syndromes such as multiple familial trichoepithelioma (MFT), but the pathogenic roles of these mutations remain unclear. Recent studies have shown that CYLD interacts with a RING finger domain protein, mind bomb homologue 2 (MIB2), in the regulation of NOTCH signaling. However, whether MIB2 is an E3 ubiquitin ligase that acts on CYLD is unknown. Here, using the cell-free-based AlphaScreen and pulldown assays to detect protein-protein interactions, along with immunofluorescence assays and murine Mib2 knockout cells and animals, we demonstrate that MIB2 promotes proteasomal degradation of CYLD and enhances NF-κB signaling. Of note, arthritic inflammation was suppressed in Mib2-deficient mice. We further observed that the ankyrin repeat in MIB2 interacts with the third CAP domain in CYLD and that MIB2 catalyzes Lys-48-linked polyubiquitination of CYLD at Lys-338 and Lys-530. MIB2-dependent CYLD degradation activated NF-κB signaling via tumor necrosis factor alpha (TNFα) stimulation and the linear ubiquitination assembly complex (LUBAC). Mib2-knockout mice had reduced serum interleukin-6 (IL-6) and exhibited suppressed inflammatory responses in the K/BxN serum-transfer arthritis model. Interestingly, MIB2 significantly enhanced the degradation of a CYLD^P904L variant identified in an individual with MFT, although the molecular pathogenesis of the disease was not clarified here. Together, these results suggest that MIB2 enhances NF-κB signaling in inflammation by promoting the ubiquitin-dependent degradation of CYLD.

Magnifying glass on spiradenoma and cylindroma histogenesis and tumorigenesis using systematic transcriptome analysis

Spiradenoma and cylindroma are related sweat gland tumors. To delineate their histogenesis, gene profiles, and their potential drivers, we performed a whole-transcriptome sequencing analysis of fourteen samples of spiradenoma/cylindroma in comparison to normal samples. A total of 12 spiradenomas, 5 cylindromas, 3 hybrid spiradenomas/cylindromas and 2 adnexal carcinomas were included in this study. 1335 characteristic genes and transcripts expressed over all 14 spiradenoma/cylindroma tumors were identified, and two groups of expression profiles were observed. Highest upregulated top 7 gene signatures characterized benign tumors with developmental and differentiation related genes, and carcinomas with top 7 genes mainly related to signaling, reorganization and metabolism of membranes. Immunohistochemistry of protein expressions validated 4 upregulated genes (ODAM, HOXB13, MYB and SOX10) considered important and as potential biomarkers for spiradenomas and cylindromas. We further compared the transcriptome of eccrine adnexal tumors with the transcriptome of adenoid cystic carcinoma (ACC) to identify the overlapping genes that may indicate histogenesis. There were 36 specific genes overlapping between adnexal carcinomas and the epithelial-dominant subtype of ACC, and 27 specific genes overlapping benign adnexal tumors with the myoepithelial-dominant subtype of ACC, At this point there is no known specific biomarker to aid in the diagnosis of eccrine spiradenoma and cylindroma in small samples or biopsies within the context of morphological overlap with ACC. In conclusion, spiradenomas and cylindromas are characterized by overexpressed developmental genes, where LHX2 and activated WNT signaling possibly drive associated carcinomas.

TRAF3/CYLD mutations identify a distinct subset of human papillomavirus-associated head and neck squamous cell carcinoma

BACKGROUND

The incidence of human papillomavirus (HPV)‐associated (HPV‐positive) head and neck squamous cell carcinoma (HNSCC) of the oropharynx has dramatically increased over the last decade and continues to rise. Newly diagnosed HPV‐positive HNSCCs in the United States currently outnumber any other HPV‐associated cancers, including cervical cancer. Despite introduction of the HPV vaccine, the epidemic of HPV‐positive HNSCC is expected to continue for approximately 60 years. Compared with patients who have tobacco‐associated HNSCC, those who have HPV‐positive HNSCC have better overall survival and response to treatment. Current treatment, including chemotherapy and radiation therapy, is associated with lifelong morbidity, and there are limited treatments and no curative options for patients who develop recurrent metastatic disease. Therapeutic de‐escalation (decreased radiation dose) is being tested through clinical trials; however, those studies select patients based solely on tumor and patient smoking characteristics. Mechanisms of HPV‐driven carcinogenesis in HNSCC are not well understood, which limits new therapeutic strategies and hinders the appropriate selection of patients for de‐escalation therapy.

METHODS

The authors analyzed HNSCC data from The Cancer Genome Atlas to identify molecular characteristics that correlate with outcomes and integration status of the HPV genome.

RESULTS

The current investigations identified a subset of HPV‐positive HNSCCs with mutations in the genes TRAF3 (tumor necrosis factor receptor‐associated factor 3) and CYLD (cylindromatosis lysine 63 deubiquitinase). Defects in TRAF3 and CYLD correlated with the activation of transcriptional factor nuclear factor κB, episomal HPV status of tumors, and improved patient survival.

CONCLUSIONS

Defects in TRAF3/CYLD were accompanied with the activation of nuclear factor κB signaling and maintenance of episomal HPV in tumors, suggesting that these mutations may support an alternative mechanism of HPV tumorigenesis in head and neck tumors. Cancer 2017;123:1778–1790. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Human papillomavirus‐associated head and neck cancer tends to respond better to treatment compared with tobacco‐associated tumors; however, patients suffer severe and long‐lasting side effects. Somatic mutations in the genes TRAF3 and CYLD identified in The Cancer Genome Atlas data set are correlated with the activation of nuclear factor‐κB, define a distinct etiologic subset of head and neck cancers, and will be useful as biomarkers for predicting improved prognosis and selecting patients with human papillomavirus‐positive head and neck cancer who may be successfully treated with de‐escalating therapy.

See also pages 1695‐98.

The cylindromatosis (CYLD) gene and head and neck tumorigenesis

Germline CYLD mutation is associated with the development of a rare inheritable syndrome, called the CYLD cutaneous syndrome. Patients with this syndrome are distinctly presented with multiple tumors in the head and neck region, which can grow in size and number over time. Some of these benign head and neck tumors can turn into malignancies in some individuals. CYLD has been identified to be the only tumor suppressor gene reported to be associated with this syndrome thus far. Here, we summarize all reported CYLD germline mutations associated with this syndrome, as well as the reported paired somatic CYLD mutations of the developed tumors. Interestingly, whole-exome sequencing (WES) studies of multiple cancer types also revealed CYLD mutations in many human malignancies, including head and neck cancers and several epithelial cancers. Currently, the role of CYLD mutations in head and neck carcinogenesis and other cancers is poorly defined. We hope that this timely review of recent findings on CYLD genetics and animal models for oncogenesis can provide important insights into the mechanism of head and neck tumorigenesis.

Brooke-Spiegler Syndrome and Phenotypic Variants: An Update

Brooke-Spiegler syndrome (BSS) is an inherited autosomal dominant disease characterized by the development of multiple adnexal cutaneous neoplasms most commonly spiradenoma, cylindroma, spiradenocylindroma, and trichoepithelioma. Multiple familial trichoepithelioma (MFT) is a phenotypic variant of the disease characterized by the development of numerous trichoepitheliomas (cribriform trichoblastoma) only. Malignant tumors arise in association with preexisting benign cutaneous neoplasms in about 5-10% of the patients . Apart from the skin, major and minor salivary glands have been rarely involved in BSS patients. Extremely rare is the occurrence of breast tumors (cylindroma). The gene implicated in the pathogenesis of the disease is the CYLD gene, a tumor suppressor gene located on chromosome 16q12-q13. Germline CYLD mutations are detected in about 80-85% of patients with the classical BSS phenotype and in about 40-50% of the individuals with the MFT phenotype using a PCR based approach with analysis of exonic sequences and exon-intron junctions of the CYLD gene. There appears to be no genotype-phenotype correlations with respect to the severity of the disease, the possibility of malignant transformation, and development of extracutaneous lesions.

Report of Three Novel Germline CYLD Mutations in Unrelated Patients with Brooke-Spiegler Syndrome, Including Classic Phenotype, Multiple Familial Trichoepitheliomas and Malignant Transformation

Brooke-Spiegler syndrome is a rare autosomal-dominant genetic disorder characterized by multiple adnexal tumors, including cylindromas, spiradenomas, spiradenocylindromas and trichoepitheliomas. It is caused by germline CYLD mutations commonly leading to a premature stop codon. We here report on 3 novel CYLD mutations in 3 unrelated BSS patients, including the classic phenotype, multiple familial trichoepitheliomas phenotype and malignant transformation. These included c.1821_1826+1delinsCT/L607Ffs*9, c.2666A>T/p.D889V and c.2712delT/p.905Kfs*8. By extending the spectrum of CYLD mutations, better understanding of the molecular mechanisms of BSS can be gained, which might later assist in finding new treatment options.

Low-grade cylindromatous adnexal carcinoma with unusual histopathological features: report of a case with comparative immunohistochemical study and meta-analysis of the literature

We present an extremely rare case of low-grade cylindromatous adnexal carcinoma (CAC) on the right chest wall of a 77-year-old man. Histopathologically, the neoplasm was initially diagnosed as a cylindroma that developed over the course of 13 years. A diagnosis of low-grade CAC was rendered after the documentation of a local recurrence and histopathology of the recurrent tumor. To further assess the evolution of low-grade CAC over time, we compared the morphology, mitotic account, proliferative markers and adhesion molecule immunoreactivity among paired primary and recurrent tumors. Unlike those earlier reported, our case showed the maintenance of tumor morphology after a recurrence without areas of obvious malignant transformation or metaplastic change. We showed here for the first time the expression of adhesion molecules of CAC/spiradenoma and a comparison of proliferation indices between a primary tumor and its local recurrence. This peculiar tumor differs from previously reported cases and harbors a malignant potential although the histopathological features of malignancy are subtle. Our meta-analysis of the literature provided background information regarding this rare entity. Alterations of E-cadherin and GCDFP-15 expression may provide additional helpful clues in differential diagnosis and determining the clinical behavior of this unusual neoplasm. Further studies are warranted to confirm the potential discriminative role of these markers.

Large germline deletions of the CYLD gene in patients with Brooke-Spiegler syndrome and multiple familial trichoepithelioma

Brooke-Spiegler syndrome (BSS) and its phenotypic variants, multiple familial trichoepithelioma (MFT) and familial cylindromatosis, are rare autosomal dominant hereditary diseases. They are characterized by the presence of multiple adnexal tumors, especially cylindromas, spiradenomas, spiradenocylindromas, and trichoepitheliomas. Implicated in the pathogenesis of the disease is the gene CYLD, which is localized on the long arm of chromosome 16. This gene encodes an evolutionarily conserved protein belonging to the deubiquitinating enzymes family, which plays a key role in many signaling pathways, especially in NF-κB, JNK, and Wnt. Less than 90 germline mutations of CYLD have been identified in patients with BSS/MFT. These mutations are mostly small alterations in the coding sequence and at exon-intron junction sites. One patient with an intronic mutation and another with a large CYLD deletion have also been recorded. In this study, the authors have analyzed a cohort of 14 patients with BSS/MFT from 13 families for large genome rearrangements by array comparative genome hybridization followed by confirmatory sequencing. We identified 2 large deletions, namely c.-34111_*297858del378779 and c.914-6398_1769del13642ins20 in patients with MFT and BSS, respectively. All other analyzable patients did not reveal any copy number alteration. It is concluded that the large rearrangements are relatively rare in patients without a germline CYLD mutation demonstrable by conventional sequencing. The pathogenetic mechanisms in patients with BSS/MFT lacking germline sequence alterations or large rearrangements in the CYLD gene remain to be clarified.

Phenotype-genotype correlations for clinical variants caused by CYLD mutations

Brooke-Spiegler syndrome (BSS; OMIM 605041) is an autosomal dominant condition characterized by skin appendageal neoplasms including cylindromas, trichoepitheliomas, and/or spiradenomas. In 1996, the gene locus for BSS was mapped to 16q12-13, and, in 2000, mutations in the cylindromatosis (CYLD) gene were determined to cause BSS, familial cylindromatosis (FC; OMIM 132700) and multiple familial trichoepithelioma type 1 (MFT1; OMIM 601606). The CYLD gene encodes an enzyme with deubiquitinase activity. To date, a total of 95 different diseases-causing mutations have been published for the CYLD gene. A summary of mutations identified in Hungarian patients and a review of previously published mutations are presented in this update. The majority of the sequence changes are frameshift (48%), nonsense (27%), missense (12%) and splice-site (11%) mutations; however, two in-frame deletions have also been reported. Most mutations are located in exons 9-20. Analysis of the identified CYLD gene mutations and the observed BSS, FC and MFT1 clinical phenotypes of the patients revealed significant genotype-phenotype correlations. Elucidation of these genotype-phenotype correlations is critical for the diagnosis of these rare monogenic skin diseases. In addition, characterizing these correlations may promote the understanding of their mechanisms and may hopefully contribute to the development of future therapeutic modalities.

Transgenic mouse model of cutaneous adnexal tumors

TMEM207 was first characterized as being an important molecule for the invasion activity of gastric signet-ring cell carcinoma cells. In order to unravel the pathological properties of TMEM207, we generated several transgenic mouse lines, designated C57BL/6-Tg (ITF-TMEM207), in which murine TMEM207 was ectopically expressed under a truncated (by ~200 bp) proximal promoter of the murine intestinal trefoil factor (ITF) gene (also known as Tff3). Unexpectedly, a C57BL/6-Tg (ITF-TMEM207) mouse line exhibited a high incidence of spontaneous intradermal tumors with histopathological features that resembled those of various human cutaneous adnexal tumors. These tumors were found in ~14% female and 13% of male 6- to 12-month-old mice. TMEM207 immunoreactivity was found in hair follicle bulge cells in non-tumorous skin, as well as in cutaneous adnexal tumors of the transgenic mouse. The ITF-TMEM207 construct in this line appeared to be inserted to a major satellite repeat sequence at chromosome 2, in which no definite coding molecule was found. In addition, we also observed cutaneous adnexal tumors in three other C57BL/6-Tg (ITF-TMEM207) transgenic mouse lines. We believe that the C57BL/6-Tg (ITF-TMEM207) mouse might be a useful model to understand human cutaneous adnexal tumors.

Molecular pathology of skin neoplasms of the head and neck

CONTEXT

Skin neoplasms include the most common malignancies affecting humans. Many show an ultraviolet (UV)-induced pathogenesis and often affect the head and neck region.

OBJECTIVE

To review literature on cutaneous neoplasms that show a predilection for the head and neck region and that are associated with molecular alterations.

DATA SOURCES

Literature review.

CONCLUSIONS

Common nonmelanoma skin cancers, such as basal and squamous cell carcinomas, show a UV-induced pathogenesis. Basal cell carcinomas are characterized by molecular alterations of the Hedgehog pathway, affecting patched and smoothened genes. While squamous cell carcinomas show UV-induced mutations in several genes, driver mutations are only beginning to be identified. In addition, certain adnexal neoplasms also predominantly affect the head and neck region and show interesting, recently discovered molecular abnormalities, or are associated with hereditary conditions whose molecular genetic pathogenesis is well understood. Furthermore, recent advances have led to an increased understanding of the molecular pathogenesis of melanoma. Certain melanoma subtypes, such as lentigo maligna melanoma and desmoplastic melanoma, which are more often seen on the chronically sun-damaged skin of the head and neck, show differences in their molecular signature when compared to the other more common subtypes, such as superficial spreading melanoma, which are more prone to occur at sites with acute intermittent sun damage. In summary, molecular alterations in cutaneous neoplasms of the head and neck are often related to UV exposure. Their molecular footprint often reflects the histologic tumor type, and familiarity with these changes will be increasingly necessary for diagnostic and therapeutic considerations.

A novel CYLD germline mutation in Brooke-Spiegler syndrome

BACKGROUND

Brooke-Spiegler syndrome (BSS) is a rare, inherited, autosomal dominant disorder characterized by the development of multiple adnexal neoplasms including spiradenomas, cylindromas, trichoepitheliomas and major and minor salivary glands neoplasms. This syndrome encompasses a wide variability of clinical phenotypes depending on the variable number of tumours present in the given patient.

OBJECTIVE

Somatic mutations in adjunct to CYLD germline mutations may play a central role in the development of the tumour phenotype and in the genotype-phenotype correlations.

METHODS

Blood sample and paraffin embedded tissue biopsied from three cylindromas, one trichoepithelioma and one spiradenomas were collected after obtaining informed consent from our patient and genomic DNA was isolated.

RESULTS

We found out a novel germline mutation in the CYLD gene in exon 15 that resulted in the deletion of one nucleotide. This gives rise to a premature translational termination codon at amino acid position 693 prior to four Cys-X-X-Cys pairs and one of the two catalytic domains of ubiquitin carboxy-terminal hydrolases. In only one cylindroma we detected the same germline mutation (c.2070delT/p.F690FfsX3) in addition to two somatic events (I645V and R936X). The presence of this unique mutation could be linked to the peculiar phenotype of our patient who presented an attenuated form of BSS, an autosomal dominant inheritance with low penetrance and no additional visceral tumours.

CONCLUSIONS

The overall phenotype of our patient may support the hypothesis that somatic mutations in adjunct to CYLD germline mutations may play a central role in the development of the tumour phenotype and in the genotype-phenotype correlations.

[CO2 laser treatment of skin cylindromas in Brooke-Spiegler syndrome]

BACKGROUND

Multiple skin cylindromas are of autosomal dominant transmission and may be associated with spiradenoma and trichoepithelioma. This condition is known as Brooke-Spiegler syndrome. The aim of this study is to compare surgical and laser treatment for these lesions.

CASE REPORTS

Five patients from a single family (two male and three female) consulted at the dermatology department for the treatment of multiple cylindromas of the scalp. The female patients presented a more severe form that had developed into "turban tumour". All patients were initially treated by surgery. Two had undergone multiple surgical excisions alone while the others had been treated with CO2 laser. One of the female patients treated with surgery had undergone complete excision of the scalp covered by total skin graft. The three patients treated with CO2 laser were completely satisfied with their therapy, which enabled a larger number of lesions to be treated at each session. They underwent one session every three months under local anaesthesia.

CONCLUSION

CO2 laser constitutes an alternative to surgery in the treatment of multiple skin cylindroma. It gives excellent cosmetic result with excellent safety and a high degree of satisfaction among treated patients. It should be proposed for patients refusing surgery or where the number of lesions enables first-line use of this approach to be envisaged.

Brooke-spiegler syndrome: a rare entity

Brooke-Spiegler syndrome is a rare entity. It is an autosomal dominant syndrome in which multiple trichoepitheliomas, cylindromas, or other adnexal tumors are seen. Very few cases of Brooke-Spiegler syndrome are reported in the literature. We came across a 40 -year-old female in which multiple trichoepitheliomas and cylindromas were seen on scalp. In view of clinical history and histopathological examination it was diagnosed as Brooke-Spiegler syndrome. We report this case because of its rarity.

Brooke–Spiegler syndrome tumor spectrum beyond the skin: a patient carrying germline R936X CYLD mutation and a somatic CYLD mutation in Brenner tumor

ABSTRACT: 

Brooke–Spiegler syndrome is a hereditary disorder characterized by a predisposition to the development of skin appendage neoplasms and the major and minor salivary glands neoplasms. The role of the CYLD mutation in visceral neoplasms is still unclear, except for the parathyroid tumor. We report the case of a 46-year-old patient with multiple cylindromas and trichoepitheliomas, a Brenner tumor of the ovary and a negative family history for Brooke–Spiegler phenotype. Genetic analysis revealed R936X germline mutation in the proband, but not in the patient’s relatives. The same somatic mutation was found in the Brenner tumor, together with a novel missense CYLD mutation (D889N), which has never been reported in the literature. A founder effect for R936X has been hypothesized due to its high prevalence; surprisingly, in our case, this mutation seems to be recognized as a de novo mutation. Future studies involving a greater number of cases, through the clinical analysis of the familial tumor spectrum and the associated molecular pathways, are necessary to understand possible genotype/phenotype correlations and the underlying molecular mechanisms.

Novel and recurrent germline and somatic mutations in a cohort of 67 patients from 48 families with Brooke-Spiegler syndrome including the phenotypic variant of multiple familial trichoepitheliomas and correlation with the histopathologic findings in 379 biopsy specimens

Brooke-Spiegler syndrome (BSS) is a rare, inherited, autosomal dominant disorder characterized by development of multiple adnexal cutaneous neoplasms including spiradenoma, cylindroma, spiradenocylindroma, and trichoepithelioma. The syndrome of multiple familial trichoepitheliomas (MFT) is considered a phenotypic variant of BSS in which patients present with trichoepitheliomas only. We studied germline and somatic mutations of the CYLD gene by direct sequencing in patients with BSS (n = 49) and MFT (n = 18) using peripheral blood and 90 samples of frozen or formalin-fixed paraffin-embedded tumor tissue selected from 379 available histology specimens. Germline CYLD mutations were found in 51 patients (76%) from 36 families (75%). Germline CYLD mutations were found in 43 of the 49 patients with BSS (88%) but in only 8 of 18 MFT cohort (44%). Twenty-one frameshift, 15 nonsense, 3 missense, and 4 splice site mutations were found in patients with BSS, whereas 1 frameshift, 5 nonsense, and 2 splice site mutations were identified in the MFT cohort. Five novel mutations were identified including 4 frameshift mutations (c.1027dupA/p.T343NfsX7, c.2155dupA/p.M719NfsX5, c.2288_2289delTT/p.F763X, and c.2641delG/p.D881TfsX32) and 1 nonsense mutation (c.2713C>T/p. Q905X). Of the 76 tumors from 32 patients with a germline CYLD mutation, 12 were spiradenomas, 15 spiradenocylindromas, 26 cylindromas, 15 trichoepitheliomas, and 7 were other tumor types. Somatic mutations were detected in 67 specimens of these 76 tumors (88%). Of the 67 somatic mutations, 21 (31%) represented a sequence alteration and 46 (69%) showed loss of heterozygosity. In the remaining 9 cases (12%), the somatic changes remained unknown. A germline CYLD mutation was not detected in 14 tumor samples from 8 patients. In these 14 tumors, somatic mutations were identified in 6 samples (43%), all consisting of sequence alterations (1 sample showed 2 different sequence alterations). In the remaining 8 samples (53%), neither germline nor somatic mutations were found in the lesional tissue. Our study increases the catalog of known CYLD mutations in patients with BSS/MFT to 86 and documents the variability of somatic mutations that may occur in them. We confirm the absence of firm genotype-phenotype correlations and the existence of a subset of patients with BSS/MFT who lack a demonstrable germline CYLD mutation. Further studies are needed to explain the reasons for this phenomenon.

A novel missense mutation of the CYLD gene identified in a Hungarian family with Brooke-Spiegler syndrome

Brooke-Spiegler syndrome (BSS; OMIM 605041) is an autosomal dominant disease characterized by skin appendage tumors due to mutations in the cylindromatosis gene (CYLD). We investigated a Hungarian BSS pedigree with two affected members, father and daughter. Direct sequencing demonstrated a novel missense mutation (c.2613C>G; p.His871Gln) in exon 19 within the ubiquitin-specific protease domain of the encoded protein. We performed preliminary analysis to reveal the functional role of this novel mutation. Our data suggest that this novel CYLD mutation leads to increased ubiquitination of NEMO through influencing deubiquitinating activity of the CYLD protein and thus may result in enhanced NF-κB signalling.

Brooke-spiegler syndrome: a rare entity

Brooke-Spiegler syndrome (BSS) is a rare autosomal dominant disorder characterized by the presence of various adnexal tumors including multiple cylindromas, trichoepitheliomas and spiradenomas. A 35-year-old female presented with multiple asymptomatic nodular lesions over face and scalp since the age of 5 years. There were no complaints suggestive of systemic involvement. Her son, elder sister, younger sister, father, father's sister, and grandmother had history of similar lesions. On examination, there were multiple asymptomatic skin-colored firm papulonodular lesions measuring from 2 to 8 mm in diameter, with smooth surface mainly affecting central part of face. Scalp showed pinkish, firm, smooth-surfaced, dome-shaped nodules measuring about 1 to 3 cm in size. Histopathological examination was consistent with trichoepitheliomas for the facial lesions and cylindromas for the scalp lesions. The diagnosis of BSS was thus confirmed.

A clinicopathologic and molecular biologic study of patients presenting with few adnexal tumors (two to four) from the morphological spectrum of Brooke-Spiegler syndrome

We report 11 individuals, each presenting with few (2-4) adnexal neoplasms histologically confirmed as belonging to the spectrum of lesions typical for Brooke-Spiegler syndrome (BSS) and/or multiple familial trichoepitheliomas. These include spiradenoma, cylindroma, spiradenocylindroma, and trichoblastoma variants. Our objective was to clarify whether this is merely a sporadic, albeit unusual, occurrence of multiple neoplasms in these patients or whether they are related to BSS and its phenotypic variant, multiple familial trichoepithelioma. Six patients presented with 2 neoplasms, 4 had 3 lesions and the last had 4 lesions. In none was there any family history of similar lesions. The 28 neoplasms consisted of 7 spiradenomas, 6 cylindromas, 5 spiradenocylindromas, and 11 trichoblastomas (6 trichoepitheliomas and 5 with mixed patterns). In 1 patient only with 2 spiradenomas, both tumors harbored identical CYLD sequence alterations (c.1112C>A/S371X) in the CYLD gene and both showed loss of heterozygosity on chromosome 16q. The remaining cases yielded neither germ line nor somatic alterations in CYLD. It is concluded that the presentation with few (2-4) cylindromas, spiradenomas, spiradenocylindromas, and trichoepitheliomas is a sporadic occurrence, and that these patients do not have any relationship to BSS.

Multiple (familial) trichoepitheliomas: a clinicopathological and molecular biological study, including CYLD and PTCH gene analysis, of a series of 16 patients

Multiple familial trichoepitheliomas (MFT) constitute an autosomally inherited syndrome possibly related to Brooke-Spiegler syndrome (BSS). Although some early studies suggested a role for the PTCH gene on chromosome 9q22.3 in the etiopathogenesis of MFT, recent studies of occasional patients with the MFT clinical phenotype identified mutations in the CYLD gene on chromosome 16q12-q13, a gene responsible for BSS. A systematic investigation of PTCH and CYLD mutations in patients with MFT has never been performed. Our main objective was to collect a reasonably large series of patients with MFT to (1) study the clinicopathological spectrum of the disease, (2) determine whether the PTCH gene is implicated in the pathogenesis of MFT, and if so (3) determine the relative frequency of CYLD and PTCH mutations, (4) establish if there may be any possible genotype-phenotype correlations, and (5) study the spectrum of somatic mutations. Clinical analysis including family histories, histopathological investigations, and molecular genetic studies were performed. There were 9 female and 7 male patients ranging in age from 11 to 63 years. They presented with multiple, small, discrete and sometimes confluent, skin-colored to pink, asymptomatic nodules preferentially located on the face, being especially prominent and confluent in the nasolabial folds and inner aspects of the eyebrows. A total of 66 conventional trichoepitheliomas (TEs) were studied microscopically. Aside from typical features of TE, some also exhibited variant morphological patterns including areas reminiscent of other benign adnexal neoplasms and melanocytic hyperplasia. In none of the 9 patients tested was a germline mutation of the PTCH gene identified. Germline CYLD mutations were detected in 6 of 13 patients tested (identical in 2 unrelated patients) including 2 novel mutations, whereas the remaining 7 individuals showed wild-type alleles. Two patients with germline wild-type CYLD showed, however, a somatic mutation in the gene (1 duplication, 1 substitution mutation). Neither CYLD nor PTCH germline mutations were found in the 5 patients in whom both genes were analyzed. MFT seems to be a phenotypic variant of BSS. The PTCH gene is rarely, if ever, involved in the pathogenesis of MFT. Absence of a germline mutation of the CYLD gene in cases harboring a somatic mutation may be explained by large deletions in the gene or by mutation in intronic sequences or in the promoter region. Considering our 5 patients with no mutation in either gene, the final possibility is that another, as yet undescribed gene (neither CYLD nor PTCH) is implicated in the pathogenesis of some patients with MFT.