Frequency of Pathogenic Germline Variants in Cancer-Susceptibility Genes in Patients With Osteosarcoma.

Importance: Osteosarcoma, the most common malignant bone tumor in children and adolescents, occurs in a high number of cancer predisposition syndromes that are defined by highly penetrant germline mutations. The germline genetic susceptibility to osteosarcoma outside of familial cancer syndromes remains unclear. Objective: To investigate the germline genetic architecture of 1244 patients with osteosarcoma. Design, Setting, and Participants: Whole-exome sequencing (n = 1104) or targeted sequencing (n = 140) of the DNA of 1244 patients with osteosarcoma from 10 participating international centers or studies was conducted from April 21, 2014, to September 1, 2017. The results were compared with the DNA of 1062 individuals without cancer assembled internally from 4 participating studies who underwent comparable whole-exome sequencing and 27 173 individuals of non-Finnish European ancestry who were identified through the Exome Aggregation Consortium (ExAC) database. In the analysis, 238 high-interest cancer-susceptibility genes were assessed followed by testing of the mutational burden across 736 additional candidate genes. Principal component analyses were used to identify 732 European patients with osteosarcoma and 994 European individuals without cancer, with outliers removed for patient-control group comparisons. Patients were subsequently compared with individuals in the ExAC group. All data were analyzed from June 1, 2017, to July 1, 2019. Main Outcomes and Measures: The frequency of rare pathogenic or likely pathogenic genetic variants. Results: Among 1244 patients with osteosarcoma (mean [SD] age at diagnosis, 16 [8.9] years [range, 2-80 years]; 684 patients [55.0%] were male), an analysis restricted to individuals with European ancestry indicated a significantly higher pathogenic or likely pathogenic variant burden in 238 high-interest cancer-susceptibility genes among patients with osteosarcoma compared with the control group (732 vs 994, respectively; P = 1.3 × 10-18). A pathogenic or likely pathogenic cancer-susceptibility gene variant was identified in 281 of 1004 patients with osteosarcoma (28.0%), of which nearly three-quarters had a variant that mapped to an autosomal-dominant gene or a known osteosarcoma-associated cancer predisposition syndrome gene. The frequency of a pathogenic or likely pathogenic cancer-susceptibility gene variant was 128 of 1062 individuals (12.1%) in the control group and 2527 of 27 173 individuals (9.3%) in the ExAC group. A higher than expected frequency of pathogenic or likely pathogenic variants was observed in genes not previously linked to osteosarcoma (eg, CDKN2A, MEN1, VHL, POT1, APC, MSH2, and ATRX) and in the Li-Fraumeni syndrome-associated gene, TP53. Conclusions and Relevance: In this study, approximately one-fourth of patients with osteosarcoma unselected for family history had a highly penetrant germline mutation requiring additional follow-up analysis and possible genetic counseling with cascade testing.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types.

BACKGROUND: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. METHODS: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. RESULTS: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. CONCLUSION: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.

A Genome-Wide Scan Identifies Variants in NFIB Associated with Metastasis in Patients with Osteosarcoma.

UNLABELLED: Metastasis is the leading cause of death in patients with osteosarcoma, the most common pediatric bone malignancy. We conducted a multistage genome-wide association study of osteosarcoma metastasis at diagnosis in 935 osteosarcoma patients to determine whether germline genetic variation contributes to risk of metastasis. We identified an SNP, rs7034162, in NFIB significantly associated with metastasis in European osteosarcoma cases, as well as in cases of African and Brazilian ancestry (meta-analysis of all cases: P = 1.2 × 10(-9); OR, 2.43; 95% confidence interval, 1.83-3.24). The risk allele was significantly associated with lowered NFIB expression, which led to increased osteosarcoma cell migration, proliferation, and colony formation. In addition, a transposon screen in mice identified a significant proportion of osteosarcomas harboring inactivating insertions in Nfib and with lowered NFIB expression. These data suggest that germline genetic variation at rs7034162 is important in osteosarcoma metastasis and that NFIB is an osteosarcoma metastasis susceptibility gene. SIGNIFICANCE: Metastasis at diagnosis in osteosarcoma is the leading cause of death in these patients. Here we show data that are supportive for the NFIB locus as associated with metastatic potential in osteosarcoma.

Genome-wide association study identifies two susceptibility loci for osteosarcoma.

Osteosarcoma is the most common primary bone malignancy of adolescents and young adults. To better understand the genetic etiology of osteosarcoma, we performed a multistage genome-wide association study consisting of 941 individuals with osteosarcoma (cases) and 3,291 cancer-free adult controls of European ancestry. Two loci achieved genome-wide significance: a locus in the GRM4 gene at 6p21.3 (encoding glutamate receptor metabotropic 4; rs1906953; P = 8.1 × 10⁻9) and a locus in the gene desert at 2p25.2 (rs7591996 and rs10208273; P = 1.0 × 10⁻8 and 2.9 × 10⁻7, respectively). These two loci warrant further exploration to uncover the biological mechanisms underlying susceptibility to osteosarcoma.

The role of epidermal growth factor receptor in chordoma pathogenesis: a potential therapeutic target.

Chordoma, the molecular hallmark of which is T (brachyury), is a rare malignant bone tumour with a high risk of local recurrence and a tumour from which metastatic disease is a common late event. Currently, there is no effective drug therapy for treating chordomas, although there is evidence that some patients respond to the empirical use of epidermal growth factor receptor (EGFR) antagonists. The aim of this study was to determine the role of EGFR in the pathogenesis of chordoma. Paraffin-embedded material from 173 chordomas from 160 patients [sacro-coccygeal (n = 94), skull-based (n = 50), and mobile spine (n = 16)] was analysed by immunohistochemistry and revealed total EGFR expression in 69% of cases analysed. Of 147 informative chordomas analysed by FISH, 38% revealed high-level EGFR polysomy, 4% high-level polysomy with focal amplification, 18% low-level polysomy, and 39% disomy. Phospho-receptor tyrosine kinase array membranes showed EGFR activation in the chordoma cell line U-CH1 and all of the three chordomas analysed. Direct sequencing of EGFR (exons 18-21), KRAS, NRAS, HRAS (exons 2, 3), and BRAF (exons 11, 15) using DNA from 62 chordomas failed to reveal mutations. PTEN expression was absent by immunohistochemistry in 19 of 147 (13%) analysed chordomas, only one of which revealed high-level polysomy of EGFR. The EGFR inhibitor tyrphostin (AG 1478) markedly inhibited proliferation of the chordoma cell line U-CH1 in vitro and diminished EGFR phosphorylation in a dose-dependant manner, a finding supported by inhibition of phosphorylated Erk1/2. p-Akt was suppressed to a much lesser degree in these experiments. There was no reduction of T as assessed by western blotting. These data implicate aberrant EGFR signalling in the pathogenesis of chordoma. This study provides a strategy for patient stratification for treatment with EGFR antagonists.

Polymerase chain reaction-based clonality analysis of cutaneous B-cell lymphoproliferative processes.

INTRODUCTION: The differential diagnosis of B-cell lymphoproliferative processes remains a challenge for pathologists, dermatologists and oncologists, despite advances in histology, immunohistochemistry and molecular biology. OBJECTIVE: Evaluate aid and limitations of clonality analysis in the diagnosis of primary cutaneous B-cell lymphomas and B-cell pseudolymphomas. METHODS: This study included 29 cases of B-cell lymphoproliferative processes classified as primary cutaneous B-cell lymphomas (13), B-cell pseudolymphomas (6) and inconclusive cases (10) using histology and immunohistochemistry. The clonality analysis was performed by polymerase chain reaction analysis of immunoglobulin light chain and heavy chain rearrangements. RESULTS: DNA quality was shown to be generally poor; eight samples were inadequate for polymerase chain reaction analysis. The results showed monoclonality in eight of the primary cutaneous B-cell lymphomas and polyclonality in four of the B-cell pseudolymphomas. In addition, monoclonality was shown in two of the inconclusive cases by histology and immunohistochemistry, demonstrating the utility of polymerase chain reaction as an ancillary diagnostic tool for primary cutaneous B-cell lymphomas. DISCUSSION: The low quality DNA extracted from these cases demanded the use of an IgH protocol that yielded small fragments and IgK. Both methods used together improved detection. CONCLUSION: Use of the two protocols, immunoglobulin heavy chain FR3-trad and immunoglobulin light chain-Kappa Biomed protocols for clonality analysis improved diagnostic accuracy.

Polymerase chain reaction-Based clonality analysis of cutaneous B-cell lymphoproliferative processes

Introduction: The differential diagnosis of B-cell lymphoproliferative processes remains a challenge for pathologists, dermatologists and oncologists, despite advances in histology, immunohistochemistry and molecular biology. Objective: Evaluate aid and limitations of clonality analysis in the diagnosis of primary cutaneous B-cell lymphomas and B-cell pseudolymphomas. Methods: This study included 29 cases of B-cell lymphoproliferative processes classified as primary cutaneous B-cell lymphomas (13), B-cell pseudolymphomas (6) and inconclusive cases (10) using histology and immunohistochemistry. The clonality analysis was performed by polymerase chain reaction analysis of immunoglobulin light chain and heavy chain rearrangements. Results: DNA quality was shown to be generally poor; eight samples were inadequate for polymerase chain reaction analysis. The results showed monoclonality in eight of the primary cutaneous B-cell lymphomas and polyclonality in four of the B-cell pseudolymphomas. In addition, monoclonality was shown in two of the inconclusive cases by histology and immunohistochemistry, demonstrating the utility of polymerase chain reaction as an ancillary diagnostic tool for primary cutaneous B-cell lymphomas. Discussion: The low quality DNA extracted from these cases demanded the use of an IgH protocol that yielded small fragments and IgK. Both methods used together improved detection. Conclusion: Use of the two protocols, immunoglobulin heavy chain FR3-trad and immunoglobulin light chain-Kappa Biomed protocols for clonality analysis improved diagnostic accuracy.

Clear cell sarcoma of the mediastinum.

A 59-year-old woman presented with a large mediastinal mass. At thoracotomy, the mass was found tightly adherent to the esophageal wall and right lower lobe of the lung. Histological examination showed a solid tumor composed of closely packed nests of cells with clear and eosinophilic cytoplasm, which were strongly and diffusely positive for S100 protein but negative for HMB45 and Melan-A. The diagnosis of clear cell sarcoma was supported by demonstrating the presence of an EWS gene rearrangement by fluorescence in situ hybridization. There was no evidence that this lesion represented metastatic disease. To the best of our knowledge, primary mediastinal clear cell sarcoma has not been previously reported in the literature. We present the case and discuss the differential diagnosis.

Paratireóides: estrutura, funções e patologia / Parathyroid glands: structure, functions and pathology

Os autores tecem considerações sobre a estrutura e funções normais das glândulas paratireóides como introdução à patologia e as repercussões clinico - patológicas tanto do excesso como da redução do paratormônio. Maior ênfase é dedicada ao hiperparatireoidismo primário quanto às causas, a fisiopatologia das alterações, os aspectos anatomopatológicos macro e microscópicos das lesões e sua patogenia, na "Osteite fibrocistica" ou "doença de von Recklinghausen dos ossos" com a correlação aos aspectos radiográficos. Apresentam caso de paciente, cuja história clinica demonstra as dificuldades encontradas para o diagnóstico da doença. Referem-se ainda às alterações e patogenia das formas de hiperparatireoidismo secundário e terciário e ao hipoparatireoidismo.

The authors present a summary on the normal anatomy and function of the parathyroid glands as well as a brief review of clinical and pathological repercussions of higher and lower parathyroid hormone production. The emphasis is given on the causes, physiopathology, anatomy, macroscopy and microscopy of the lesions and their role in the genesis of fibrocystic osteitis, also known as Von Recklinhausen disease of the bones. Radiological correlation is also given. The authors show the challenges for the diagnosis in the same cases. We also write about secondary and tertiary hyperparathyroidism, as well as hypoparathyroidism.

Adamantinoma de ossos longos / Adamantinoma of the long bones

OBJETIVOS: Estudar retrospectivamente 18 casos de pacientes com adamantinoma de ossos longos, todos localizados na tíbia; ressaltar a importância da biópsia e a correlação com métodos de imagem para diagnóstico diferencial com osteofibrodisplasia e displasia fibrosa; tecer considerações sobre a natureza do adamantinoma de ossos longos, cujo nome deve-se à analogia histológica com o adamantinoma (ameloblastoma) da mandíbula. MÉTODOS: Foram analisados o quadro clínico, imagens e exames anatomopatológicos complementados com imunohistoquímica e a evolução dos pacientes. Todos foram submetidos a tratamento cirúrgico, 17 com "tibialização" da fíbula e os demais com amputação. RESULTADOS: A evolução pós-cirúrgica mostrou-se imprevisível e não relacionada com os aspectos clínicos ou histopatológicos. Dois pacientes evoluíram com metástases pulmonares e morreram. Seis não tiveram recidivas ou metástases e estão clinicamente curados. Os demais, após alta hospitalar não retornaram à consulta. CONCLUSÕES: Trata-se de rara neoplasia constituída por estruturas epiteliais e mesenquimais que devem ser diagnosticadas com precisão, antes de qualquer procedimento. O tratamento é cirúrgico com ressecção do tumor com boa margem oncológica. O comportamento biológico é variável e imprevisível.

OBJECTIVE: To make a retrospective study of 18 cases of patients with adamantinoma of the long bone, all of them located in the tibia; to point to the relevance of biopsy and the correlation with imaging methods in order to have a differential diagnosis with osteofibrous dysplasia and fibrous dysplasia; to comment on the nature of long bone adamantinoma, whose name is due to the histological analogy with the adamantinoma (ameloblastoma) of the jaw. METHODS: A review was made of the clinical condition, images, and anatomopathological exams supplemented with immunohistochemical essays, and the evolution of the patients. All of them were submitted to surgical treatment, 17 with "tibialization" of the fibula and the others with amputation. RESULTS: The post-surgical evolution showed to be unpredictable and not related to clinical or histopathological aspects. Two patients had an evolution with lung metastasis and died. Six did not present recurrent disease or metastases, and are clinically cured. The others, after being released from hospital, did not return for consultation. CONCLUSIONS: This is a rare neoplasia made of epithelial and mesenchymal structures that must be accurately diagnosed before any procedure is attempted. Treatment is surgical, with tumor resection with a good oncologic margin. The biological behavior is varied and unpredictable.

Detection of beta-catenin mutations in paraffin-embedded sporadic desmoid-type fibromatosis by mutation-specific restriction enzyme digestion (MSRED): an ancillary diagnostic tool.

Desmoid-type fibromatosis is a locally aggressive deep soft tissue tumor. Some cases are associated with adenosis polyposis coli germline mutations whereas others harbor somatic beta-catenin point mutations mainly in exon 3, codons 41 and 45. These mutations result in stabilization of beta-catenin, and activation of the Wnt signaling pathway. The aim of this study was to determine the specificity and sensitivity of these 3 most common beta-catenin mutations in the diagnosis of desmoid-type fibromatosis using paraffin-embedded material. The results were compared with nuclear expression of beta-catenin. Mutation-specific restriction enzyme digestion methodology was employed to detect the 3 mutations. One hundred and thirty-three cases were analyzed, including 76 desmoid-type, and 18 superficial fibromatosis, in addition to a further 39 fibromatosis mimics. A restriction site was present for analysis of the codon 41 mutation. Mismatch primers were designed for the codon 45 mutations. Mutations were detected in 66 cases (87%) of 76 desmoid-type fibromatosis (71 extra-abdominal). Of these, 34 (45%) were in codon 45 (TCT>TTT), 27 (35%) in codon 41 (ACC>GCC), and 5 (7%) in codon 45 (TCT>CCT). No mutations were detected in the other lesions studied. All desmoid-type fibromatosis cases and 72% of the mimics tested showed nuclear positivity for beta-catenin indicating immunohistochemistry is a sensitive but not a specific test for desmoid-type fibromatosis. In contrast, to date, beta-catenin mutations have not been detected in any lesions which mimic desmoid-type fibromatosis. Mutation-specific restriction enzyme digestion, a simple and efficient means of detecting the common beta-catenin mutations in desmoid-type fibromatosis, complements light microscopy in reaching a diagnosis.

Detection of SS18-SSX fusion transcripts in formalin-fixed paraffin-embedded neoplasms: analysis of conventional RT-PCR, qRT-PCR and dual color FISH as diagnostic tools for synovial sarcoma.

Synovial Sarcoma consistently harbors t(X;18) resulting in SS18-SSX1, SS18-SSX2 and rarely SS18-SSX4 fusion transcripts. Of 328 cases included in our study, synovial sarcoma was either the primary diagnosis or was very high in the differential diagnosis in 134 cases: of these, amplifiable cDNA was obtained from 131. SS18-SSX fusion products were found in 126 (96%) cases (74 SS18-SSX1, 52 SS18-SSX2), using quantitative and 120 by conventional reverse transcriptase-polymerase chain reaction (RT-PCR). One hundred and one cases in a tissue microarray, analyzed by fluorescence in situ hybridization (FISH), revealed that 87 (86%) showed SS18 rearrangement: four RT-PCR positive cases, reported as negative for FISH, showed loss of one spectrum green signal, and 15 cases had multiple copies of the SS18 gene: both findings are potentially problematic when interpreting results. One of three cases, not analyzed by RT-PCR reaction owing to poor quality RNA, was positive by FISH. SS18-SSX1 was present in 56 monophasic and 18 biphasic synovial sarcoma: SS18-SSX2 was detected in 41 monophasic and 11 biphasic synovial sarcoma. Poorly differentiated areas were identified in 44 cases (31%). There was no statistically significant association between biphasic, monophasic and fusion type. Five cases were negative for SS18 rearrangement by all methods, three of which were pleural-sited neoplasms. Following clinical input, a diagnosis of mesothelioma was favored in one case, a sarcoma, not otherwise specified in another and a solitary fibrous tumor in the third case. The possibility of a malignant peripheral nerve sheath tumor could not be excluded in the other two cases. We concluded that the employment of a combination of molecular approaches is a powerful aid to diagnosing synovial sarcoma giving at least 96% sensitivity and 100% specificity but results must be interpreted in the light of other modalities such as clinical findings and immunohistochemical data.

Detecção da fusão SS18-SSX em material parafinado e comparação de métodos moleculares como ferramentas no diagnóstico do sarcoma sinovial / Detection of SS18-SSX fusion transcripts in formalin-fixed parafin-emedded tissue and comparison of molecular methods as diagnostic tools for synovial sarcoma

Dos 134 Sarcoma Sinoviais estudados, a fusão SS18-SSX foi identificada em 126 (96 por cento) casos (74 SS18-SSX1, 52 SS18-SSX2) através de qRT-PCR e 120 por RT-PCR convencional. 101 casos no array de tecidos, analisados por FISH revelaram 87 (86 por cento) mostraram rearranjo do SS18. Um dos 3 casos não analisados por RT-PCR por não ter gerado cDNA de qualidade foi positivo por FISH. Áreas pouco diferenciadas foram identificadas em 44 casos (31 por cento). Não houve correlação estatisticamente significante entre os subtipos bifásico, monofásico e o tipo de fusão. Cinco casos foram negativos através dos três métodos utilizados. Concluímos que os métodos moleculares são ferramentas auxiliares importantes para o diagnóstico de SS com 96 por cento de sensibilidade e 100 por cento de especificidade.

Of 134 Synovial Sarcomas, SS18-SSX fusion products were found in 126 (96 per cent) cases using quantitative and 120 by conventional RT-PCR. 101 cases in a tissue microarray, analyzed by FISH, revealed that 87 (86 per cent) showed SS18 rearrangement. One of 3 cases, not analyzed by RT-PCR due to poor quality RNA, was positive by FISH. Poorly differentiated areas were identified in 44 cases (31 per cent). There was no statistically significant association between biphasic, monophasic and fusion type. Five cases were negative for SS18 rearrangement by all methods. We concluded that the employment of a combination of molecular approaches is a powerful aid to diagnosing synovial sarcoma giving at least 96 per cent sensitivity and 100 poer cent specificity.

Injection of phosphatidylcholine in fat tissue: experimental study of local action in rabbits.

BACKGROUND: Subcutaneous phosphatidylcholine to cause local lipolysis has been performed effectively and safely in the nonsurgical treatment of periorbital fat pads and also in the treatment of localized fat deposits in the abdomen, neck, arms and thighs. However, the studies do not explain the mechanism through which injectable phosphatidylcholine causes localized fat reduction. This study aimed to compare the local action of a phosphatidylcholine formulation with that of a physiologic saline solution in a histologic study investigating the fat tissue of rabbits. METHODS: Using a randomized, blind approach, 10 rabbits were injected with an experimental assay of phosphatidylcholine (the biologic model), and another 10 rabbits were injected with physiologic saline. A histologic study was conducted, and the Mann-Whitney test was applied. RESULTS: A marked difference was observed between the two groups with respect to necrosis, inflammatory exudation, and fibrosis. CONCLUSION: Necrosis of the fat cells in all the phosphatidylcholine-injected animals was observed. Further studies should be performed to clarify and determine the mechanisms of action.

Glimatosis cerebri simulating an acute diffuse encephalomyelitis: case report

Neuroradiologic, neuropathologic and immunohistochemical features are reported in a young man with a impairment of the central nervous system mimicking an acute diffuse encephalomyelitis. A white male, 17 years old, healthy till 4 months before, when developed a right hemiparesis and after 2 months a bilateral hemiparesis with a progressive impairment of several cranial nerves. Magnetic resonance imaging showed multiple lesions without a mass effect that suggested myelin loss. He remained unconscious for almost one month before dying of pneumonia. The neuropathologic examination showed a heavy brain (1505 g) with herniations and a large right midbrain. There were several soft and pink areas mainly at the right midbrain, left cerebellum and in the white matter of the left cerebral hemisphere. The histopathologic sections showed diffuse blastomatous proliferation without total replacement or destruction of the original tissue. The tumor cells had astrocytic, oligodendrocytic and spongioblastic phenotypes, some of them with a GFAP-positive reactivity. There were focal anaplastic changes. The diagnosis of "gliomatosis cerebri" was only possible by the autopsy.