Background: Osteosarcoma is an aggressive bone tumor with a high risk of lung metastasis, which severely affects patient survival. EMT plays a major role in tumor spread, therapy resistance, and cancer stemness. This review explores how EMT contributes to osteosarcoma metastasis and the underlying molecular mechanisms. Methods: We reviewed recent studies on EMT-related signaling pathways, transcription factors, and regulatory RNAs in osteosarcoma. We also examined the role of the tumor microenvironment. Results: EMT promotes cell detachment, migration, and lung colonization. Key pathways such as TGF-β, MAPK, PI3K/Akt, STAT3, Notch, and Wnt/β-catenin are involved. Non-coding RNAs further regulate EMT by interacting with these pathways. The tumor microenvironment, including hypoxia and immune cells, also supports EMT and metastasis. Conclusions: EMT is a key driver of metastasis and poor outcomes in osteosarcoma. Targeting EMT and its regulators may help prevent lung spread and improve treatment. Future strategies combining EMT inhibition with existing therapies could be promising for clinical application.

Background: Malignant lymphoma is the most common hematological malignancy; however, primary central nervous system lymphoma accounts for only a small percentage of non-Hodgkin lymphoma (NHL). Among these, primary cauda equina lymphoma (CEL) is extremely uncommon. Its rarity and atypical clinical presentation often make diagnosis challenging. Case Presentation: An 80-year-old man presented with progressive gait disturbance, lower-extremity weakness, and numbness. MRI revealed diffuse swelling and homogeneous gadolinium enhancement of the cauda equina at T12–L1; additionally, CSF cytology identified malignant lymphocytes. Open biopsy confirmed a diagnosis of diffuse large B-cell lymphoma. At diagnosis, the patient was classified as Ann Arbor stage IV, and the clinical parameters corresponded to a high-risk International Prognostic Index (IPI) category. The patient received five courses of immunochemotherapy with rituximab, methotrexate, vincristine, and procarbazine (R-MPV), resulting in marked radiological improvement and functional recovery, achieving a complete response. However, consolidation therapy was discontinued as the patient did not wish to continue. Unfortunately, intracranial relapse occurred four months later, and the patient ultimately succumbed to infectious complications. Only 29 cases of primary CEL have been reported. For all cases, a biopsy with histopathological examination is required for a definitive diagnosis. Currently, combined chemotherapy and radiotherapy are considered the standard treatment. This case was diagnosed through nerve biopsy with cauda equina at T12 to L1 levels, and immunochemotherapy successfully reduced the lesion while improving lower extremity function. Conclusions: Despite the considerable burden on patients, nerve biopsy is necessary for primary CEL to obtain a diagnosis and an early therapeutic approach for both neurological and vital prognoses.

Introduction: Preiser’s disease refers to a rare idiopathic avascular necrosis of the scaphoid that often leads to pole collapse and poor clinical outcomes when managed conservatively. Vascularized bone grafting (VBG) using the 1,2 intercompartmental supraretinacular artery (ICSRA) flap has been used to restore perfusion, but its treatment efficacy across different disease stages remains unclear. Methods: We retrospectively reviewed eight women (mean age 60.6 years) who were treated using 1,2 ICSRA VBG between 2006 and 2022. Disease stage was determined using the Herbert radiographic classification (one stage 1, four stage 2, and three stage 3 cases). Clinical parameters [grip strength, range of motion, Disabilities of the Arm, Shoulder, and Hand (DASH) scores, Mayo Wrist Scores] and radiographic progression were assessed after a mean follow-up of 3.6 years. Contralateral scaphoid morphology was evaluated to explore any potential anatomical predisposition. Results: On average, there were improvements in grip strength (9.5 to 16.6 kg), dorsal flexion (49° to 65°), DASH score (49.5 to 10.6), and Mayo score in all cases. Radiographically, the stage 1 case did not exhibit any progression, one stage 2 case progressed, and all stage 3 cases progressed despite symptomatic improvement. Three patients exhibited type 2 scaphoid morphology, but no correlation with outcomes was observed. Conclusion: VBG using the 1,2 ICSRA flap results in favorable clinical/radiographic outcomes in early Preiser’s disease (stages 1–2), effectively preserving function and stability. In stage 3 disease, VBG may provide symptomatic relief but does not prevent progression. This warrants careful patient selection and consideration of alternative reconstructive options.