Long-read single-molecule maps of the functional methylome

We report on the development of a methylation analysis workflow for optical detection of fluorescent methylation profiles along chromosomal DNA molecules. In combination with Bionano Genomics genome mapping technology, these profiles provide a hybrid genetic/epigenetic genome-wide map composed of DNA molecules spanning hundreds of kilobase pairs. The method provides kilobase pair–scale genomic methylation patterns comparable to whole-genome bisulfite sequencing (WGBS) along genes and regulatory elements. These long single-molecule reads allow for methylation variation calling and analysis of large structural aberrations such as pathogenic macrosatellite arrays not accessible to single-cell second-generation sequencing. The method is applied here to study facioscapulohumeral muscular dystrophy (FSHD), simultaneously recording the haplotype, copy number, and methylation status of the disease-associated, highly repetitive locus on Chromosome 4q.

[Eosinophilic granulomatosis with polyangiitis presenting as livedo racemosa]

As a rare antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss syndrome) is characterized by asthma, severe peripheral eosinophilia and the presence of extravascular granulomas. Cutaneous involvement usually includes palpable purpura or cutaneous to subcutaneous nodes. We present the case of a 43-year-old woman with EPGA and the unusual cutaneous manifestation of livedo racemosa.

[Tinea barbae profunda by Arthroderma benhamiae. A diagnostic challenge]

Dermatomycoses due to pets and farm animals are often a clinical and diagnostic challenge for dermatologists. A 24-year-old man presented with inflammatory skin changes on his cheeks and chin. Because of negative fungal culture and the clinical appearance of a highly inflammatory process, our first diagnosis was a bacterial pyoderma. Polymerase chain reaction (PCR) identified Arthroderma benhamiae in both the patient and his guinea pig. A. benhamiae is a zoophilic dermatophyte which belongs to the Trichophyton mentagrophytes-complex. The fungus is acquired from guinea pigs and causes highly inflammatory forms of tinea. PCR-based diagnostics are quick and simple tools to identify this pathogen, so that suitable antimycotic therapy can be initiated quickly.

[Metastatic malignant melanoma. Successfull treatment with ipilimumab]

A 73-year-old man, in whom 26 years ago a malignant melanoma with cervical lymph node metastases of the right retroauricular region was diagnosed, developed BRAF V600E-negative distant metastases, which progressed during both monochemotherapy and polychemotherapy. Therefore he was started on ipilimumab in a dose of 3 mg/kg body weight four times in intervals of 3 weeks. Subsequently, there was an almost complete regression of distant metastases. In several phase III trials a significant survival benefit has been identified for patients treated with ipilimumab. The human monoclonal antibody has been approved since July 2011 as a second-line treatment in Germany and was incorporated in January 2013 into the new guidelines for the treatment of malignant melanoma. The CTLA-4 antibody is the first drug that can improve significantly survival in patients with metastatic melanoma. In advanced (unresectable or metastatic) melanoma, immunostimulatory treatment with ipilimumab represents a new therapeutic option.

[NK/T-cell lymphoma, nasal type with cutaneous dissemination]

Extranodal NK/T-cell lymphoma, nasal type, is a lymphoproliferative disorder originating from peripheral T-cells or natural killer (NK) cells. While it is a rare disease in Europe, it is more frequent in Asia and South America. It is associated with Epstein-Barr virus (EBV) infection and characterized by an extremely aggressive course and poor prognosis. We report a 46-year-old Caucasian woman who presented with multiple subcutaneous, painful nodules on the trunk first noticed a few weeks earlier. In addition to dermatological findings, the patient reported a 4-months history of necrotizing nasopharyngeal inflammation of unclear origin. Due to nonspecific histological and clinical findings mimicking a chronic inflammatory condition, a diagnosis of Wegener disease was made and immunosuppressive therapy with azathioprine was initiated. However the disease progressed under therapy. Histopathological reevaluation and immunophenotyping revealed a disseminated NK/T-cell lymphoma, nasal type. In the case of an unspecific chronic inflammatory process in the nasopharyngeal space one should always consider the possibility of this rare lymphoma, even in Europe.

[Hereditary cutaneous leiomyomatosis]

The occurrence of multiple cutaneous leiomyomas can be indicative of hereditary cutaneous leiomyomatosis. This autosomal dominant disorder is due to germline mutations in the fumarate hydratase (FH) gene. Associations with uterine myomas and renal cell carcinomas have been described and are referred to as Multiple Cutaneous and Uterine Leiomyomas (MCUL) or Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC), respectively. A 34-year-old man presented with multiple red-brown papules and nodules. After histopathologic confirmation of piloleiomyomas, we made the diagnosis of hereditary cutaneous leiomyomatosis. Taking into consideration the aforementioned complications, close interdisciplinary management of these patients and regular screening examinations within affected families are mandatory.

[Epithelioid sarcoma of the right hand]

A 35-year-old man presented with swelling, indurations and nodules on the thumb, wrist and fingers of the right hand. History revealed that the findings were slowly progressive and had been present for at least eight years. Histopathologic analysis of a nodule showed a diffuse infiltrate with atypical spindle-shaped cells and expression of cytokeratin, epithelial membrane antigen (EMA) and CD34; the diagnosis of epithelioid sarcoma (ES) was made. Because of diffuse extension of the tumor, forearm amputation was performed along with axillary dissection and local radiotherapy because of axillary lymph node metastases. ES is a rare subtype of soft tissue sarcoma with a harmless appearance and indolent course over years. ES represents a diagnostic challenge, with consequent delay in diagnosis and adequate treatment. The most important measure in the treatment of ES is early surgical excision with adjuvant radiotherapy if local metastases are present.

[Malassezia folliculitis in an immunocompromised patient]

Malassezia folliculitis (synonym: Pityrosporum folliculitis) is a polymorphic dermatomycosis characterized by the development of small papules and pustules. In severe cases, molluscoid comedonal papules are typical. The disease occurs mainly in sebum-rich areas of the face, back and chest, frequently affecting patients under immunosuppressive therapy. We report a case of Malassezia folliculitis observed in a heart transplant recipient who was successfully treated with itraconazole. Moreover, we summarize the taxonomy of the genus Malassezia as well as diagnostic and therapeutic measures of the related folliculitis.

The new polyomavirus (MCPyV) does not affect the clinical course in MCCs

Since 2008, a new polyomavirus (MCPyV) in Merkel cell carcinomas (MCC) has been described, but little is known about its impact on the clinical course. The purpose of this study was to determine the presence of MCPyV in a large sample and to correlate the results with the clinical course of the disease. 59 samples from 44 patients were analysed for the presence of MCPyV using the primers LT3, VP1 and LT1. The clinical records of these patients were evaluated and correlated with the presence of MCPyV. 58% of specimens were positive for MCPyV. Of these, LT3 was positive in 53%, VP1 in 37% and LT1 in 10%. 57% of primary tumours and 53% of metastases were positive for LT3; the numbers for VP1 and LT1 were lower. There was no correlation between the detection of MCPyV in the primary tumour and the appearance of metastases. The survival time was statistically independent from the presence of MCPyV. There is a striking occurrence of MCPyV in MCC, but whether it affects the clinical course remains unclear.

[Merkel cell carcinoma. Viral genesis and new therapeutic options?]

Merkel cell carcinoma (cutaneous neuroendocrine carcinoma) is a rare, highly malignant, neuroendocrine tumor of the skin with predominance in older patients. The tumor is most often located in the sun-exposed skin of the head, the neck and -as in our patient - the extremities. Notably, the tumor bears a high risk of an early regional lymph node as well as distant metastases. Clinically, only a presumptive diagnosis of Merkel cell carcinoma can be established. The definite diagnosis is made by histological and immunohistological methods. Surgical excision with a safety margin should be combined with sentinel lymph node biopsy. In advanced tumor stages (lymph node or visceral metastasis), a remission can be achieved by different chemotherapy schedules in combination with radiation. Recently, a previously unknown polyomavirus, named Merkel cell polyomavirus (MCV or MCPyV), has been identified in 80% of Merkel cell carcinomas. In the near future, these novel findings could be utilized to distinguish Merkel cell carcinoma from small round cell cancers and could lead to the development of new therapeutic options.

[Shulman's syndrome (eosinophilic fasciitis)]

Eosinophilic fasciitis is a rare disease characterized by edema, painful indurations, and progressive muscle weakness. Mainly the extremities are involved. We report on a 22-year-old woman with eosinophilic fasciitis presenting with progressive muscle weakness of both hands and feet and a reduced general condition. She showed symmetrical and firm swelling of the extremities with painful restriction of joint movement. Systemic treatment with glucocorticosteroids as well as physiotherapy and manual lymphatic drainage led to continuous improvement of her symptoms. The differentiation from other diseases, such as systemic scleroderma, eosinophilia-myalgia syndrome, and pseudoscleroderma, might be difficult at the beginning of the disease. The gold standard for diagnosis is--as was done in our case--a deep skin-to-muscle biopsy. Further imaging, especially magnetic resonance imaging, can support the diagnostic procedure.

[Tuberous sclerosis: diagnostic criteria and new treatment approaches]

With a prevalence of 1 in 6,000 births, tuberous sclerosis is a relatively frequent hamartoma and tumor syndrome inherited as an autosomal dominant trait, which manifests primarily on the skin and in the central nervous system. Decisive factors for morbidity and mortality and thus for the prognosis are the changes in the central nervous system in the form of cortical hamartomas. Treatment for many years consisted solely in using nonspecific symptomatic approaches; dermatological therapy comprised mainly laser or electroacoustic ablation of facial angiofibromas. New models of therapy hinder the pathogenesis of tuberous sclerosis. Various studies provided evidence that the macrolide rapamycin decreases growth of brain and kidney tumors by specific inhibition of mTOR kinase. Synergistic effects were observed in combination therapy with the cytokine IFN-gamma.

Multicentre intraindividual randomized trial of topical methyl aminolaevulinate-photodynamic therapy vs. cryotherapy for multiple actinic keratoses on the extremities

BACKGROUND

Methyl aminolaevulinate-photodynamic therapy (MAL-PDT) is an effective treatment in facial/scalp actinic keratosis (AK).

OBJECTIVES

The aims of this study were to compare efficacy, safety, cosmetic outcome and patient preference of MAL-PDT vs. cryotherapy in patients with AK at other locations.

METHODS

A multicentre, controlled, randomized, open, intraindividual, right-left comparison was performed. Patients with nonhyperkeratotic AK were treated once with MAL-PDT and cryotherapy on either side of the body. At week 12, lesions showing noncomplete response were retreated. The primary efficacy variable was the lesion response at week 24. Investigator's assessment of cosmetic outcome, patient's preference in terms of cosmetic outcome and a patient preference questionnaire were also analysed at week 24.

RESULTS

In total, of 121 patients with 1343 lesions (98% located on the extremities and the remainder on the trunk and neck) were included. Both treatments provided a high mean percentage reduction in lesion count at week 24 with significantly higher efficacy for cryotherapy: 78% for MAL-PDT and 88% for cryotherapy (P=0.002, per protocol population). Investigator's assessment of cosmetic outcome was significantly better for MAL-PDT than cryotherapy (P<0.001), 79% of lesions having an excellent cosmetic outcome with MAL-PDT vs. 56% with cryotherapy at week 24. The cosmetic outcome achieved by MAL-PDT compared with cryotherapy was also preferred by patients (50% vs. 22%, respectively, P<0.001), and 59% of patients would prefer to have any new lesions treated with MAL-PDT compared with 25% with cryotherapy (P<0.001). Both treatment regimens were safe and well tolerated.

CONCLUSIONS

MAL-PDT showed inferior efficacy for treatment of non-face/scalp AK compared with cryotherapy. However, both treatments showed high efficacy, and MAL-PDT conveyed the advantages of better cosmesis and higher patient preference.

[Basal cell carcinoma. Molecular genetics and unusual clinical features]

Basal cell carcinoma is the most common human cancer. Its incidence is steadily increasing. The development of basal cell carcinoma is linked to genetic factors, including the individual skin phototype, as well as the cumulative exposure to UVB. The vast majority of basal cell carcinomas are sporadic tumors, while familial cases associated with certain hereditary syndromes are less common. At the molecular level, basal cell carcinomas are characterized by aberrant activation of sonic hedgehog signaling, usually due to mutations either in the ptch or smoh genes. In addition, about half of the cases carry mutations in the tp53 tumor suppressor gene, which are often UVB-associated C-->T transition mutations. Clinically, basal cell carcinomas may show a high degree of phenotypical variability. In particular, tumors occurring in atypical locations, showing an unusual clinical appearance, or imitating other skin diseases may cause diagnostic problems. This review article summarizes the current state of the art concerning the etiology, predisposition and molecular genetics of basal cell carcinoma. In addition, examples of unusual clinical manifestations are illustrated.

Multiple eruptive myxoid dermatofibromas: report of first case and review of literature

Multiple eruptive dermatofibromas are a rare presentation of dermatofibroma which are frequently associated with underlying diseases such as human immunodeficiency virus infection or lupus erythematosus. Eruptive dermatofibromas generally present a characteristic histology with a poorly circumscribed lesion showing hyperplasia of the epidermis, prominent bundles of collagen and a diffuse proliferation of fibrocytes. We report an unusual case of multiple eruptive dermatofibromas showing massive depositions of mucin within the dermis. A 20-year-old woman presented with nearly 100 red to yellowish papules and nodules distributed symmetrically all over the integument which developed over a period of 9 years. Comprehensive clinical and laboratory diagnostics showed no signs indicating any underlying disease. To our knowledge this is the first report of multiple eruptive myxoid dermatofibromas. We consider this case to be a unique presentation of multiple eruptive dermatofibroma showing massive deposition of mucin.

Imiquimod 5% cream for the treatment of superficial basal cell carcinoma: results from a randomized vehicle-controlled phase III study in Europe

BACKGROUND

Imiquimod is an immune response modifier that acts through toll-like receptor 7 to induce cytokine production and a subsequent innate and adaptive cell-mediated immune response. Clinical studies have demonstrated clinical and histological clearance of superficial basal cell carcinoma (sBCC) after treatment with imiquimod 5% cream.

OBJECTIVES

To evaluate the safety and clinical efficacy of imiquimod (Aldaratrade mark; 3M Pharmaceuticals, St Paul, MN, U.S.A.) 5% cream for the treatment of sBCC in a multicentre, randomized, parallel, vehicle-controlled, double-blind, phase III clinical study conducted at 26 centres in Europe.

METHODS

Subjects who had at least one histologically confirmed sBCC tumour were randomized to apply imiquimod or vehicle cream to the target tumour once daily, seven times per week (7 x/week) for 6 weeks. The target tumour location was identified with an indelible ink mark before treatment initiation. The treated tumour site was clinically assessed for treatment response at 12 weeks post-treatment and was then excised for histological evaluation. Efficacy assessments included the composite response rates (proportion of subjects with clinical and histological clearance) and response rates solely based on histology (proportion of subjects with histological clearance). Safety assessments, which included adverse events and scoring of local skin reactions (LSRs), were carried out throughout the study.

RESULTS

In total, 166 subjects were enrolled in this study. For the intent-to-treat dataset, there was a statistically significant difference between imiquimod and vehicle groups for both composite clearance rates (clinical and histological assessments) and histological clearance rates. Composite clearance was demonstrated in 77% and 6% of subjects treated with imiquimod and vehicle cream, respectively. Histological clearance was demonstrated in 80% and 6% of subjects treated with imiquimod and vehicle cream, respectively. The most frequently reported safety findings were investigator-assessed LSRs and spontaneous reports by subjects of application site reactions, which occurred more frequently in the imiquimod group than in the vehicle group.

CONCLUSIONS

Imiquimod 5% cream administered 7 x/week for 6 weeks is a safe and effective treatment for sBCC when compared with vehicle cream.

Somatic mutations in the PTCH, SMOH, SUFUH and TP53 genes in sporadic basal cell carcinomas

BACKGROUND

Basal cell carcinoma (BCC) of the skin is the most common human cancer. The genetic alterations underlying BCC development are only partly understood.

OBJECTIVES

To investigate further the molecular genetics of sporadic BCCs, we performed mutation analyses of 10 skin cancer-associated genes in 42 tumours.

METHODS

Single-strand conformational polymorphism analysis followed by DNA sequencing was used to screen for mutations in the sonic hedgehog pathway genes PTCH, SMOH, SUFUH and GLI1, in the TP53 tumour suppressor gene, and in the proto-oncogenes NRAS, KRAS, HRAS, BRAF and CTNNB1. Microsatellite markers flanking the PTCH, SUFUH and TP53 loci at 9q22, 10q24 and 17p13, respectively, were studied for loss of heterozygosity (LOH).

RESULTS

PTCH mutations were found in 28 of 42 tumours (67%). Microsatellite analysis revealed LOH on 9q22 in 20 of 38 tumours investigated (53%), including 14 tumours with and six tumours without PTCH mutations. SMOH mutations were identified in four of the 42 BCCs (10%) while two tumours demonstrated mutations in SUFUH, including one missense mutation and one silent mutation. None of the BCCs showed LOH at markers flanking the SUFUH locus. Seventeen BCCs (40%) carried TP53 mutations, with only three tumours showing evidence of biallelic TP53 inactivation. TP53 mutations were present in BCCs with and without mutations in PTCH, SMOH or SUFUH. Interestingly, 72% of the TP53 alterations were presumably ultraviolet (UV)-induced transition mutations. In contrast, only 40% of the PTCH and SMOH alterations corresponded to UV signature mutations. No mutations were identified in GLI1, NRAS, KRAS, HRAS, BRAF or CTNNB1.

CONCLUSIONS

Our data confirm the importance of PTCH, SMOH and TP53 mutations in the pathogenesis of sporadic BCCs. SUFUH alterations are restricted to individual cases while the other investigated genes do not appear to be important targets for mutations in BCCs.

[Neurocutaneous melanosis and malignant melanoma]

A 36-year-old man presented with a giant congenital melanocytic nevus and multiple disseminated melanocytic nevi. After he had developed neurological symptoms (grand mal seizures), a cerebral metastasis of a malignant melanoma without a primary melanoma was found. The patient was diagnosed as having a neurocutaneous melanosis with a cerebral metastasis. In spite of a variety of therapeutic attempts (surgery, radiation therapy and chemotherapy) he followed a rapidly progressive, lethal course with increased intracranial pressure, hydrocephalus and spinal metastases.

[Ulcus terebrans. Therapy options and their limits]

Basal cell carcinoma (BCC) is the most common tumor in humans and is defined as a slow-growing, locally invasive, epithelial skin tumor which rarely metastasizes. The first line treatment is surgical excision with histologic examination of the tumor margins, but numerous alternative therapies are available. A 75-year old patient with the most destructive form of BCC, ulcus terebrans, involving the scalp and invading the frontal bone. We discuss the problems and therapeutic limitations for this unusual BCC variant.

[Hereditary tumor syndromes. Cutaneous manifestations and molecular pathogenesis of Gorlin and Cowden syndromes]

Several hereditary tumor syndromes are associated with characteristic skin lesions which may facilitate an early diagnosis. We summarize clinical features and recent progress in understanding the etiology and pathogenesis of two selected tumor syndromes, namely nevoid basal cell carcinoma syndrome (Gorlin syndrome) and Cowden syndrome. Both are autosomal dominantly inherited disorders. Nevoid basal cell carcinoma syndrome is characterized by the early onset of multiple basal cell carcinomas as as well as developmental defects and a predisposition for other benign and malignant tumors. The syndrome is caused by germline mutations in the PTCH tumor suppressor gene. Cowden syndrome is associated with pathognomonic mucocutaneous lesions, such as facial trichilemmomas, acral keratoses, and mucocutaneous papillomatosis. In addition, Cowden patients are predisposed to carcinomas of the thyroid, breast and endometrium. Cowden syndrome is caused by germline mutations in the PTEN tumor suppressor gene. Identification of the genes causing hereditary tumor syndromes as well as generation of genetically engineered mouse models have greatly advanced our understanding of the molecular pathogenesis of these diseases. Furthermore, novel pathogenesis-based pharmacological strategies are being developed that promise to improve prevention and therapy.

Molekulare Grundlagen und pathogeneseorientierte Therapie epithelialer Tumoren der Haut

Basal cell carcinomas and squamous cell carcinomas are the most common human cancers and increasing in incidence. The development of novel, pathogenesis-based therapies requires a better knowledge of the molecular mechanisms leading to the development of these tumors. Basal cell carcinomas are characterized by aberrant activation of Sonic-Hedgehog (SHH) signaling due to mutations in the PTCH or SMOH genes. In addition, about 50% of the cases carry mutations in the TP53 tumor suppressor gene. Squamous cell carcinomas lack alterations of SHH signaling, while TP53 mutations are detectable in virtually all cases. Alterations in cell cycle regulatory genes, such as CDKN2A, are also common. Recently, specific inhibitors of the SHH-signaling pathway have been developed and shown promising results in preclinical studies on experimental basal cell carcinomas. However, the clinical significance of such targeted molecular therapy remains to be evaluated. Another successful pathogenesis-based therapy, which is already in clinical use, is the administration of topic immune response modifier imiquimod. This drug can eradicate non-melanoma skin cancers by different mechanisms, including cytokine-mediated stimulation of the anti-tumor immune response, as well as the induction of tumor cell apoptosis.

Cowden's disease: clinical and molecular genetic findings in a patient with a novel PTEN germline mutation

We report a 54-year-old woman with Cowden's disease (CD) who was found to carry a novel germline mutation in the PTEN gene. The mutation (c.334C-->G) introduced a splice donor site within exon 5 that caused the expression of an aberrant transcript lacking 159 nucleotides corresponding to codons 112-164. Clinically, the patient showed multiple benign hamartomatous lesions of the skin, papillomatosis of the lips and oral mucosa, polyposis coli and bilateral fibrocystic disease of the breast. In addition, she developed different types of malignant neoplasms, including bilateral carcinomas of the breast and malignant melanomas of the skin. Molecular genetic analysis of a benign skin hamartoma and an invasive ductal breast carcinoma revealed loss of heterozygosity (LOH) at microsatellite markers on chromosome 10 in the carcinoma but not in the hamartoma. The breast carcinoma additionally carried a somatic TP53 point mutation (c.466C-->G; R156G) that was associated with LOH on 17p and nuclear p53 protein accumulation. Taken together, our findings indicate that benign hamartomas in CD may develop without loss of the second (wild-type) PTEN allele, whereas the pathogenesis of malignant tumours, such as breast carcinomas, appears to require the complete inactivation of Pten as well as further alterations such as the loss of p53-dependent growth control.