Histiocytic Sarcoma with an Unusual Clinical Manifestation Imitating Malignant Vascular Tumor: A Case Report.

BACKGROUND Histiocytic sarcoma is a rare malignant hematopoietic neoplasm with morphologic and immunohistochemical features of histiocytic differentiation, usually with unfavorable prognosis. Despite aggressive biological behavior, in subgroup of patients with localized disease, the prognosis can be very good. Few publications are available on localized cases of histiocytic sarcoma. These occur infrequently and continue to be a poorly-recognized morphological entity. CASE REPORT A 73-year old man treated for Parkinson syndrome presented with a tumor resistance on the dorsal surface of the left forearm. This lesion was clinically seen as an organized hematoma and was surgically resected. Histologically, the tumor was situated in the dermis and subcutis and it consisted of multiple neoplastic nodules. Vasoformative growth patterns with the vascular-like spaces containing erythrocytes and hemosiderin pigment presence simulated the morphology of angiosarcoma. Based on the immunohistochemical characteristics, we diagnosed the tumor as cutaneous histiocytic sarcoma. Genetic analysis revealed immunoglobulin heavy-chain gene rearrangement without any concomitant hematological malignancy. The patient demonstrated no systemic disease or impairment associated with diagnosed histiocytic sarcoma, and no recurrence has been found to date. CONCLUSIONS We report a case of primary cutaneous histiocytic sarcoma with an excellent outcome after surgical treatment only. Clinical data and histopathological and immunohistochemical evaluation were essential to rule out other malignant tumors in the differential diagnosis. Genetic analysis together with up-to-date knowledge and understanding of principles of tumorous transformations helped to diagnose this poorly-recognized entity with various clinical behaviors.

Development and extensive analytical validation of deep amplicon sequencing for detecting KRAS and NRAS mutations in metastatic colorectal cancer samples.

The presence of wild-type RAS alleles, as determined by genotyping codons 12, 13, 59, 61, 117, and 146, is a prerequisite for personalized anti-EGFR treatment of metastatic colorectal cancer (mCRC) patients. Here we describe analytical validation of in-house developed massively parallel sequencing technology (MPS) in comparison to the in vitro diagnostics (IVD) certified qPCR method. DNA extracted from FFPE samples from CRC patients (n=703) and reference standards (n=33) were tested for KRAS and NRAS mutations in 6 codons of exons 2, 3, and 4 using deep amplicon sequencing (DAS) on a MiSeq benchtop sequencer (Illumina). Two different amplicon lengths and two different library preparation methods (long-RAS and short-RAS) were tested in order to evaluate their impact on DAS performance. In parallel, identical tumor DNA was tested by the following IVD assays: therascreen KRAS RGQ PCR Kit (Qiagen), cobas® KRAS Mutation Test (Roche Diagnostics), and SNaPshot assay (Thermo Fisher Scientific). Both DAS assays detected all the mutations present in reference standards and external quality control samples, except for the artificially generated KRAS codon 146 mutation. The DAS assays performed sufficient analytical specificity and sensitivity (≥0.95). The use of shorter amplicons prolonged the preparation steps but significantly improved the sequencing success rate of FFPE-derived DNA. RAS mutation frequencies in the Czech CRC patients were similar to previous reports, although rare mutations were also detected. DAS with short amplicons is a good strategy for routine assessment of somatic mutations in low-quality FFPE-derived DNA.

IDH Mutation Analysis in Glioma Patients by CADMA Compared with SNaPshot Assay and two Immunohistochemical Methods.

Mutations in IDH1/2 genes are a marker of good prognosis for glioma patients, associated with low grade gliomas and secondary glioblastomas. Immunohistochemistry and Sanger sequencing are current standards for IDH1/2 genotyping while many other methods exist. The aim of this study was to validate Competitive amplification of differentially melting amplicons (CADMA) PCR for IDH genotyping by comparison with SNaPshot assay and two immunohistochemical methods. In our study, 87 glioma patients (46 from Olomouc and 41 from Ostrava) were analyzed. IDH1/2 mutations in native bioptical samples were analyzed at DNA level by CADMA and SNaPshot while IDH1 mutations in FFPE samples were analyzed at protein level by two IHC methods. CADMA PCR sensitivity for IDH1 was 96.4% and specificity 100% for 86 concluded samples. SNaPshot assay sensitivity was 92.9% and specificity of 100% for 85 concluded samples. IHC in the laboratory no. 2 reached sensitivity 85.7% and specificity 100% for 86 concluded samples. IHC in the laboratory no. 4 reached sensitivity of 96.4% and specificity of 79.7% in 74 concluded samples. Only one IDH2 mutation was found by SNaPshot while CADMA yielded false negative result. In conclusion, CADMA is a valid method for IDH1 p.(R132H) testing with higher sensitivity than SNaPshot assay. Also, molecular genetic methods of IDH1 testing from native samples were more robust than IHC from FFPE.

[Use of PCR for diagnosing cat-scratch disease].

OBJECTIVE: The diagnosis of Bartonella henselae by polymerase chain reaction (PCR) in lymph nodes removed in 10 patients with serologically confirmed evidence cat-scratch disease. MATERIAL AND METHODS: The 2015-2018 group consisted of 10 patients with serologically confirmed cat-scratch disease, all of them having positive IgG antibodies and 6 patients also positive IgM antibodies against B. henselae. The group included 4 men and 6 women, 7 children and 3 adults, aged 5-52 years. Eleven lymph nodes obtained from the 10 patients were formalin-fixed paraffin-embedded. Variants of granulomatous inflammation were found in 9 patients; a 13-year-old boy had Hodgkin's lymphoma. DNA isolation was performed with cobas® DNA Sample Preparation Kit (Roche). DNA of Bartonella spp. was detected by real-time PCR with BactoReal® Kit Bartonella spp. (Ingenetix) detecting the gltA gene specific for the genus Bartonella. RESULTS: Four of the 10 patients tested positive or borderline positive for Bartonella when their histological material was analyzed by PCR. One patient with 2 lymph nodes examined showed a positive result for only 1 lymph node. One adult male had a positive result; three children showed borderline positive results. Of those, two patients had suppurative granulomatous and the other 2 patients had necrotizing suppurative granulomatous inflammation as histological findings. All 4 patients had positive IgM antibodies against B. henselae. The boy with lymphoma had a negative PCR result. CONCLUSION: Serological tests combined with histological examination of lymph nodes and PCR may improve the diagnosis of cat- scratch disease.

Crohn's disease - genetic factors and progress of the disease.

BACKGROUND AND OBJECTIVES: Crohn's disease is a multifactorial inflammatory disease affecting mainly the gastrointestinal tract. The genetic factors that are involved in the disease include mainly three mutations of the gene NOD2/CARD15 (R702W, G908R, 3020insC). The aim of this study was to determine the relationship between the presence of these variants and disease phenotype. MATERIAL AND METHODS: 70 patients with Crohn's disease were examined for the presence of the above-mentioned mutations. The researchers used the medical records to retrospectively obtain clinical data and together with the information obtained prospectively according to the protocol they analysed the connection between gene mutations and disease phenotype. RESULTS: At least one mutation was found in 22 patients with Crohn's disease (32%), four patients were found to have two different mutations (composed heterozygotes - 6%) and six patients (9%) were homozygotes for the 3020insC gene. No significant differences were found between the groups with wild-type form and the mutated form of the NOD2 / CARD15 gene with respect to age at the time of diagnosis, form of the disease or localization according to the Montreal classification. CONCLUSION: Mutations of the NOD2 / CARD15 gene did not significantly affect the frequency of reoperations, homozygotes with 3020insC gene mutations, however, represented a high risk group. The phenotype was not related significantly to the presence of the examined mutations.

Comparison of the prevalence of KRAS-LCS6 polymorphism (rs61764370) within different tumour types (colorectal, breast, non-small cell lung cancer and brain tumours). A study of the Czech population.

AIMS: A germline SNP (rs61764370) is located in a let-7 complementary site (LCS6) in the 3'UTR of KRAS oncogene, and it was found to alter the binding capability of the mature let-7 microRNA to the KRAS mRNA. The aim of the study was to evaluate the frequency of the KRAS-LCS6 variant allele in different cancer types that included patients with colorectal cancer (CRC), breast cancer (BC), non-small cell lung cancer (NSCLC) and brain tumour patient subgroups from the Czech Republic. The occurrence of this genetic variant was correlated with the presence of selected somatic mutations representing predictive biomarkers in the respective tumours. METHODS: DNA of tumour tissues was isolated from 428 colorectal cancer samples, 311 non-small cell lung cancer samples, 195 breast cancer samples and 151 samples with brain tumour. Analysis of SNP (rs61764370) was performed by the PCR+RFLP method and direct sequencing. KRAS, BRAF and EGFR mutation status was assessed using real-time PCR. The status of the HER2 gene was assessed using the FISH method. RESULTS: The KRAS-LCS6 TG genotype has been detected in 16.4% (32/195) of breast cancer cases (in HER2 positive breast cancer 3.3%, in HER2 negative breast cancer 20.1%), in 12.4% (53/428) of CRC cases (KRAS/BRAF wild type CRC in 10.6%, KRAS mutant CRC in 10.1%, BRAF V600E mutant CRC in 18.5%), in 13.2% (41/311) of NSCLC samples, (EGFR mutant NSCLC patients in 8%, EGFR wild type NSCLC in 12.9%), and 17.9% (27/151) of brain tumour cases. The KRAS-LCS6 TG genotype was not significantly different across the studied tumours. In our study, the GG genotype has not been found among the cancer samples. CONCLUSIONS: Based on the findings, it is concluded that the occurrence of the KRAS-LCS6 TG genotype was statistically significantly different in association with status of the HER2 gene in breast cancer. Furthermore, significant association between the mutation status of analysed somatic variants in genes of the EGFR signalling pathway (KRAS, BRAF, EGFR) and the KRAS-LCS6 genotype in colorectal cancer and NSCLC has not been established.

[Crohn's disease - etiopathogenetic factors]. / Crohnova nemoc - genetické faktory z pohledu etiopatogeneze.

Crohn's disease is often purely inflammatory, but most patients develop complicated disease with strictures or fistulae. Specific etiopathogenesis of this severe disease is not definitely clear despite research efforts and learning of many pathogenetic mechanisms. Many studies have suggested that NOD2 mutations are associated with increased risk of complicated disease. Presence of NOD2 mutation itself is just one of factors contributing to development of this disease. Genetically predisposed individuals in combination with influence of environmental factors result in a disturbed innate (i.e., disturbed intestinal barrier, Paneth cell dysfunction) and adaptive (i.e., imbalance of effector and regulatory T cells and cytokines, migration and retention of leukocytes) immune response towards a diminished diversity of commensal microbiota. Data of meta-analysis made so far provide ambiguous evidence to support top-down therapy based solely on single NOD2 mutations, but suggest that targeted early-intensive therapy for high-risk patients with two NOD2 mutations might be beneficial, but more prospective trials could answer these questions.

[KRAS mutation testing in therapeutic algorithm for treatment of metastatic colorectal carcinoma]. / Vysetrení mutacního statutu genu KRAS jako soucást algoritmu lécby metastatického kolorektálního karcinomu.

Targeted therapy has become an integral part of treatment procedures of malignant tumors. Colorectal carcinomas are frequently targeted with monoclonal anti-EGFR antibodies (cetuximab and panitumumab). Activating somatic mutations in codons 12 and 13 of the exon 2 of KRAS gene are considered negative predictive factors of response to anti-EGFR therapy in patients with metastatic colorectal cancer. In the Czech Republic, evaluation of mutational status of KRAS gene is performed in several referral laboratories. In 2009, these laboratories performed 2580 tests of the KRAS mutational status--out of these, 60.2% cases reported non-mutated, wild-type KRAS. In one of the referral laboratories, we demonstrate the logistics of KRAS testing procedure. Stratification of patients with metastatic colorectal tumors based on their KRAS mutational status has evolved to a standard procedure. Laboratories performing these methods shall therefore adhere to the recommendations of the professional and accredited societies.