[Detection of MDM2 gene amplification by fluorescence in situ hybridization and its diagnostic value in low-grade osteosarcoma].

Objective: To investigate the diagnostic value of detecting MDM2 gene amplification by fluorescence in situ hybridization (FISH) in low-grade osteosarcoma (LGOS). Methods: Thirty cases of parosteal osteosarcoma (POS) and 14 cases of low-grade central osteosarcoma (LGCOS) from April 2009 to August 2022 at Beijing Jishuitan Hospital, Capital Medical University were analyzed for the presence of MDM2 gene amplification by FISH. Fifty-eight additional cases were used as negative controls (including 28 cases of fibrous dysplasia, 5 cases of giant cell tumor, 4 cases of conventional osteosarcoma, 2 cases each of periosteal osteosarcoma, reparative changes after fracture, pleomorphic undifferentiated sarcoma, low grade myofibroblastic sarcoma, fibrous dysplasia with malignant transformation, one case each of leiomyosarcoma, sclerosing epithelioid fibrosarcoma, malignant peripheral nerve sheath tumor, desmoplastic fibroma of bone, solitary fibrous tumor, aneurysmal bone cyst, clear cell chondrosarcoma, osteofibrous dysplasia, and 3 cases of unclassified spindle cell tumor). Results: Among the 30 patients with POS, 15 were male and 15 were female, ranging in age from 10 to 59 years (mean 35 years, median 30.5 years). Among the 14 patients with LGCOS, four were male and 10 were female, ranging in age from 15 to 56 years (mean 37 years, median 36 years). All except one case were successfully detected by FISH. MDM2 gene amplification was detected in 27 cases of POS (27/29,91.3%) and 8 cases of LGCOS (8/14). All the negative controls were negative for MDM2 gene amplification. The positive rate of MDM2 gene amplification was significantly different between the case group and the control group (P<0.05). The sensitivity and specificity of MDM2 gene amplification in diagnosing POS and LGCOS were 91.3% and 100.0%; and 57.1% and 100.0%, respectively. The sensitivity and specificity of MDM2 gene amplification in diagnosing LGOS (including POS and LGCOS) were 81.3% and 100.0%, respectively. In cases where MDM2 gene was amplified, the MDM2 amplified signal was clustered. Nine cases showed increased CEP12 signal different from polyploidy which was displayed as small and weak signal points or cloud flocculent and cluster signals. Conclusions: Detection of MDM2 gene amplification by FISH is a highly sensitive and specific marker for LGOS. The interpretation criteria for FISH detection of MDM2 amplification are currently not unified. The signal characteristics need more attention when interpreting.

[Analysis of noise reduction measures in a noise workshop handover control room].

Objective: To explore the sound insulation, sound absorption and other noise reduction transformation methods in a noise workshop handover control room. Methods: In December 2021, through the occupational health investigation and on-site testing of the handover control room of a noise workshop, the causes of excessive noise were analyzed, and the transformation design scheme to reduce noise was proposed and the effect was analyzed. Results: Before the transformation, the peak frequency band noise intensity of the noise workshop handover control room was 112.8 dB (A), and the peak frequency was 1000 Hz. After noise reduction, the theoretical calculated control value was 61.0 dB (A), and the measured noise intensity was 59.8 dB (A) . Conclusion: The noise intensity of the handover control room is reduced after noise reduction, which is in line with the contact limit requirements of the control room in GBZ 1-2010 "Hygienic Standards for the Design of Industrial Enterprises", and has reference significance for noise control engineering.

[Mutation characteristics of osteosarcoma: a single center study of 64 cases using next-generation sequencing].

Objective: To investigate the distribution and characteristics of gene mutations in osteosarcoma, and to analyze the frequency and types of detectable mutations, and to identify potential targets for individualized treatment of osteosarcoma. Methods: The fresh tissue or paraffin-embedded tissue samples of 64 cases of osteosarcoma that were surgically resected or biopsied and then subject to next generation sequencing, were collected from Beijing Jishuitan Hospital, China from November 2018 to December 2021. The tumor DNA was extracted to detect the somatic and germline mutations using targeted sequencing technology. Results: Among the 64 patients, 41 were males and 23 were females. The patient age ranged from 6 to 65 years with a median age of 17 years, including 36 children (under 18 years old) and 28 adults. There were 52 cases of conventional osteosarcoma, 3 cases of telangiectatic osteosarcoma, 7 cases of secondary osteosarcoma, and 2 cases of parosteosarcoma. The detection rate of gene mutations was overall 84.4% (54/64). There were 324 variations in 180 mutated genes, including 125 genes with copy number variations, 109 single nucleotide variants, 83 insertions or deletions, and 7 gene fusions. The most common mutated genes were TP53, VEGFA, CCND3, ATRX, MYC, RB1, PTEN, GLI1, CDK4 and PTPRD. Among them, TP53 had the highest mutation rate (21/64, 32.8%), single nucleotide variant was the main mutation type (14/23, 60.9%), and 2 cases carried the TP53 germline mutation. VEGFA and CCND3 showed copy number amplification simultaneously in 7 cases. Conclusions: The high-frequency mutation of TP53 suggests that it plays an important role in the pathogenesis and development of osteosarcoma. VEGFA, CCND3 and ATRX are mutated genes in osteosarcoma and worthy of further studies. Combination of pathologic diagnosis and next generation sequencing with clinical practice can guide individualized treatment for patients with refractory, recurrent and metastatic osteosarcoma.

[Primary intraosseous Rosai-Dorfman disease: a clinicopathological analysis of fourteen cases].

Objective: To investigate the clinicopathological characteristics, histogenesis, immunophenotypes and molecular genetic features of primary intraosseous Rosai-Dorfman disease (RDD) for improving diagnostic accuracy and differential diagnosis. Methods: This retrospective study included 14 RDD cases diagnosed from January 2009 to January 2019 at Beijing Jishuitan Hospital, China. The immunohistochemical staining for S-100, cyclin D1, CD1a and CD207 expression was analyzed. The BRAF V600E and KRAS mutation analyses were performed using the Scorpions amplification refractory mutation system (ARMS) fluorescence quantitative PCR. Results: There were 6 female and 8 male patients, aged from 2 to 64 years (mean 31.4 years). All of the 14 cases occurred in the bone without lymph node disease, while one patient developed additional lesions within vertebra and nasal cavity. Radiographically, the lesions were lytic with sclerotic margins. Histologically, the lesions percolated through the medullary cavity in an infiltrative fashion and alternating hyper- and hypo-cellular regions of histiocytic clusters (seen as alternating dark and light zones at low magnification). Large histiocytes also showed emperipolesis. Some cases had areas of fibrosis and dense lymphoplasmacytic infiltrates. There were vasculitis and an increased number of plasma cells in the cases involving multiple sites. One case showed concurrence of RDD and Langerhans cell histiocytosis(LCH) with inconspicuous increase of Langerhans histiocytes. Immunohistochemical staining showed that the large histiocytes were positive for S-100, CD68 and CD163 in all cases. The nuclear immunoreactivity for cyclin D1 was observed in 13 of the 14 cases. S-100, CD1a and CD207 were positive in the case with concurrence of RDD and LCH. ARMS-PCR results showed that BRAF V600E mutation was observed in the cases with concurrence of RDD and LCH, while there were no KRAS mutations (7/7). Follow-up information was available for 12 patients and ranged from 9 to 49 months. Three of the 12 patients experienced recurrences after the first surgery. Conclusions: Primary intraosseous RDD is rare, and its concurrence with LCH is a very rare phenomenon. Its clinical symptoms, imaging, and pathological manifestations need to be distinguished from other bone lesions. The molecular detection of BRAF V600E and the nuclear expression of cyclin D1 mutations can be used for the diagnosis and differential diagnosis of RDD.

[Role of histological evaluation of periprosthetic tissue in diagnosis of periprosthetic joint infection].

Objective: To evaluate the role of histologicalpathology in the diagnosis of periprosthetic joint infection. Methods: A total of 145 cases of joint arthroplasty during October 2017 and October 2018 from Beijing Jishuitan Hospital were collected. There were 23 cases of infection, including knee joint arthroplasty (12 cases) and hip arthroplasty (11 cases). There were 17 females and 6 males. Patients' age ranged from 39 to 76 years (mean 63 years). The infection was diagnosed if there were >5 neutrophils per high power field in at least 5 high power field. The permanent sections were examined twice separately by two pathologists, and the interval time of histologic examination was at least two weeks. Sensitivity (SE), specificity (SP), positive predictivevalue (PPV), and negative predictive value (NPV) were calculated. The consistency evaluation of histologic examination of two pathologists was calculated by Kappa analysis. Results: The neutrophil cells could locate scattered or focally in the synovium tissue of periprosthetic joint infection. Somewhere, the infiltration of vessel and the perivascular distribution could also exist. Opportunity coincidence rate between two pathologists was 91.3% (Kappa=0.817). The results showed that SE was 60.9%, SP was 100.0%, NPV was 93.1%, PPV was 100.0%. Conclusions: The presence of polymorphonuclear cells in histologic examination is correlated with infection. There was high consistency between histologic examination and clinical diagnosis of joint arthroplasty.

[Clinicopathological and ALVAL score analysis of pseudotumor-like tissue around aseptic joint arthroplasty].

Objective: To analyze the clinicopathological features of pseudotumor-like tissue around aseptic joint arthroplasty and aseptic lymphocytic vasculitis-associated lesions (ALVAL) scores. The characters of wear granules were observed. Methods: Total 122 cases were retrieved from the surgical pathology files between May 2015 and August 2018 in the department of pathology in Beijing Jishuitan Hospital, which included the knee joint arthroplasty (10 cases) and hip arthroplasty (112 cases). There were 62 females and 60 males. Patients' age ranged from 29 to 86 years (mean 56 years). The pseudotumor-like tissue around aseptic joint arthroplasty were stained with HE and analyzed by two ALVAL score systems. The characters of wear granules were observed by light microscope and polarized light. Results: The cohort included 62 females and 60 males. Patients' age ranged from 29 to 86 years (mean 56 years). Compbell-ALVAL system includes synovial lining,inflammatory infiltrate and tissue organization. The scores were: low (0-4): 18cases; moderate (5-8): 101 cases; high (9-10): 3 cases. Oxford-ALVAL system only evaluated the inflammatory infiltrate,and the scores were:0 grade:56 cases; 1 grade:51 cases; 2 grade: 12 cases; 3 grade:3 cases. Cases with high score in the Compbell-ALVAL system were concordant with the 3 grade of the Oxford-ALVAL system. Under light microscope,the metal particles were small black granules; the polyethylene fibers were needle-like and easily visible in polarized light. The polymethylmethacrylate showed clear spaces because of particle melting. Conclusions: The Compbell-ALVAL scoring system is based on the histologic analysis of pseudotumor-like tissue around aseptic joint arthroplasty, and the Oxford-ALVAL scoring systems is based on lymphocytic response. The wear particles could be differentiated by the features in the light microscope.