Musculoskeletal Tumors

Novel insights into the multifaceted roles of m6A-modified LncRNAs in cancers: biological functions and therapeutic applications

N6-methyladenosine (m⁶A) is considered as the most common and important internal transcript modification in several diseases like type 2 diabetes, schizophrenia and especially cancer. As a main target of m⁶A methylation, long non-coding RNAs (lncRNAs) have been proved to regulate cellular processes at various levels, including epigenetic modification, transcriptional, post-transcriptional, translational and post-translational regulation. Recently, accumulating evidence suggests that m⁶A-modified lncRNAs greatly participate in the tumorigenesis of cancers. In this review, we systematically summarized the biogenesis of m⁶A-modified lncRNAs and the identified m⁶A-lncRNAs in a variety of cancers, as well as their potential diagnostic and therapeutic applications as biomarkers and therapeutic targets, hoping to shed light on the novel strategies for cancer treatment.

A case report of arthroscopic treatment of a retro-patellar GCTTS causing anterior knee pain

INTRODUCTION AND IMPORTANCE

Giant cell tumor of tendon sheath (GCTTS) is a common soft tissue tumor in hands and feet; however, it is rare in knee joints.

CASE PRESENTATION

We present a case of a 52-year-old female who had a retropatellar tendon giant cell tumor (GCT) in the right knee, causing vague anterior knee pain.

CLINICAL DISCUSSION

Anterior knee pain is a challenging complaint in orthopedics due to the multiple causative reasons, the combination of several complex etiologies, and the lack of clear guidelines for an effective treatment.

CONCLUSION

This case report aims to shed light on unlikely pathologies in complex cases. GCTTS is a rare lesion to affect the retropatellar region. However, we must keep it in mind when dealing with challenging anterior vague knee pain complaints. A comprehensive examination is essential; surgical experience and extended follow-up are mandatory for avoiding complications.

The Outcome of Children With Malignant Bone Tumors: A Single-Center Experience

Malignant bone tumors (MBT) account for 3% to 5% of cancers in children younger than 15 years. We aimed to report the outcome of children with MBT in 10 years in Southern Iran. During the study period, 100 patients (57 Osteosarcoma, 43 Ewing sarcoma) with an M/F ratio of 1.56 and a median age of 13.8 years (3.8-17.9) were diagnosed. Metastasis occurred in 27% of patients, mostly in the first 3 months of diagnosis. The mean survival time of MBT altogether was 94.1 months (95% CI: 86.5-101.7). The 5-year overall survival and event-free survivals were 85.2% (95% CI: 74%-91.8%) and 69.2% (95% CI: 56%-79%), respectively. Metastasis was the only independent risk factor of death in our study cohort (Hazard ratio 36.7, 95% CI: 4.8-282.6, P = .001) MBT in children mostly occur in adolescent boys. About one-third of them become metastatic, which is significantly associated with poor outcomes.

Gait Disorders

As a child matures so does the child's gait pattern. Gait changes in pediatric patients will be expected and sequential as developmental milestones. Gait changes may also represent normal variations along an appropriate spectrum. There are times when changes in gait are due to urgent orthopedic or medical conditions, and those should not be overlooked. A good understanding of pediatric gait development and a basic understanding of gait assessment are critical for the primary care physician who cares for children.

Application of modified closed biopsy in rabbit model of VX2-transplanted bone tumor

Background

This study was aimed to explore the application value of modified closed biopsy technique in puncture biopsy of rabbit VX2 transplanted bone tumor model.

Methods

VX2 tumor was transplanted into the bilateral tibia of 30 rabbits through the tibial plateau to make the model of VX2 transplanted bone tumor. Seven days after modeling, the proximal tibia biopsy was performed under the guidance of X-ray, and the biopsy specimen was examined pathologically. The left leg was biopsied with modified closed biopsy technique (experimental group), and the right leg was biopsied with hollow needle (control group). After 14 days of modeling, all rabbits were killed after X-ray examination around the puncture hole, and the soft tissue around the puncture hole was taken for pathological examination, and the expression levels of PCNA and CD34 in the tissue extract were detected by enzyme-linked immunosorbent assay (ELISA).

Results

By the end of the experiment, a total of 3 rabbits died, and finally, 27 rabbits were included in the study. Tumor cells were detected in all the intramedullary specimens obtained by puncture biopsy. On the 14th day after modeling, X-ray showed that the occurrence rate of periosteal reaction and extraosseous high-density shadow around the puncture hole was 14.81% (4/27) in the experimental group and 40.74% (11/27) in the control group. The difference was statistically significant (P<0.05). The pathological results of soft tissue around the puncture hole showed that the tumor cell metastasis rate was 29.63% (8/27) in the experimental group and 100% (27/27) in the control group, and the difference was statistically significant (P<0.05). The expression levels of PCNA and CD34 in the experimental group were lower than those in the control group (P < 0.05).

Conclusion

Both the modified closed biopsy technique and needle aspiration biopsy can provide sufficient biopsy tissue for the diagnosis of VX2-transplanted bone tumor in rabbits. At the same time, the improved closed biopsy technique has a certain application value in preventing local metastasis of tumor cells along the puncture channel.

Biological reconstruction in the treatment of extremity sarcoma in femur, tibia, and humerus

To understand the feasibility, clinical effect, and complications related to biological reconstruction techniques for long limb malignant bone tumors after excision.This retrospective study included eighty patients with malignant bone tumors treated at our hospital between January 2007 and January 2019. After tumor resection, 52 cases of intercalary and 28 cases of osteoarticular bone grafts were used. The implanted bone included devitalized recycling bone, fibular, and allograft.The average follow up period was 42.19 months for 80 patients, among whom 15 (18.75%) died. The 5-year EFS and OS were 58% and 69%, respectively. The average length of the replanted bone was 18.57 cm. The MSTS scores of intercalary and osteoarticular bone grafts were 87.24% and 64.00%, respectively. In 23 cases (44.23%) of metaphyseal and 26 cases (32.5%) of the diaphysis, bone graft union was obtained at the first stage. The factors affecting bone union were the patient's gender, age, devitalization bone methods and whether the implanted bone was completely fixed. Postoperative complications included delayed bone union in 15 patients, fractures in 25 cases, nonunion in 22 cases, bone resorption in 14 cases, and postoperative infection in 4 cases. Twenty-eight cases of bone grafting required revision surgery, including replacement of internal fixation, autologous bone graft, debridement, removal of internal fixation, and replacement with prosthetic replacement.Biological reconstructions with massive bone grafts are useful in the reconstruction of certain malignant extremity bone tumors after wide excision.

Musculoskeletal small biopsies from small patients: current status in 2 academic hospitals

INTRODUCTION

Pediatric bone and soft tissue (BST) lesions typically undergo biopsy prior to treatment, which commonly involves core needle biopsy (CNB) and/or fine-needle aspiration biopsy (FNAB). This study looks at the utility of small biopsies in the current diagnosis of pediatric BST lesions from 2 institutions.

MATERIALS AND METHODS

A retrospective search of BST small biopsies obtained during a 2-year time period (2018-2019) at 2 academic institutions was performed to look at clinicopathologic features, biopsy diagnoses, and correlation with follow-up.

RESULTS

A total of 96 pediatric patients (average age 11.2 years, range: 10 months-19 years) with BST lesions underwent a small biopsy, which represents 5% of the total BST lesions biopsied. The results show that the majority of lesions were benign (65%), and diagnosed by CNB alone (73%); a combination of FNAB and CNB (16%), and FNAB alone (11%), were less frequent. The CNB was effective in making a definitive diagnosis in 93% of cases and overall small biopsy was effective in 91% of the cases. Cases with definitive diagnoses on small biopsy were more likely to have concurrent CNB or characteristic ancillary studies performed.

CONCLUSIONS

Although pediatric BST lesions constitute only 5% of all BST lesions biopsied, minimally invasive small biopsies with cytologic evaluation for triage and appropriate ancillary study utilization can help render specific diagnoses that help to determine the appropriate treatment for young patients with BST lesions. The current diagnostic approach frequently involves CNB with intraprocedural evaluation or concurrent FNAB, with fewer biopsied by FNAB alone.