Primary Spinal Intradural Extramedullary Mesenchymal Chondrosarcoma

A Web-Based Prediction Model for Overall Survival of Elderly Patients With Malignant Bone Tumors: A Population-Based Study

Background: Malignant bone tumors (MBT) are one of the causes of death in elderly patients. The purpose of our study is to establish a nomogram to predict the overall survival (OS) of elderly patients with MBT.

Methods: The clinicopathological data of all elderly patients with MBT from 2004 to 2018 were downloaded from the SEER database. They were randomly assigned to the training set (70%) and validation set (30%). Univariate and multivariate Cox regression analysis was used to identify independent risk factors for elderly patients with MBT. A nomogram was built based on these risk factors to predict the 1-, 3-, and 5-year OS of elderly patients with MBT. Then, used the consistency index (C-index), calibration curve, and the area under the receiver operating curve (AUC) to evaluate the accuracy and discrimination of the prediction model was. Decision curve analysis (DCA) was used to assess the clinical potential application value of the nomogram. Based on the scores on the nomogram, patients were divided into high- and low-risk groups. The Kaplan-Meier (K-M) curve was used to test the difference in survival between the two patients.

Results: A total of 1,641 patients were included, and they were randomly assigned to the training set (N = 1,156) and the validation set (N = 485). The univariate and multivariate analysis of the training set suggested that age, sex, race, primary site, histologic type, grade, stage, M stage, surgery, and tumor size were independent risk factors for elderly patients with MBT. The C-index of the training set and the validation set were 0.779 [0.759–0.799] and 0.801 [0.772–0.830], respectively. The AUC of the training and validation sets also showed similar results. The calibration curves of the training and validation sets indicated that the observed and predicted values were highly consistent. DCA suggested that the nomogram had potential clinical value compared with traditional TNM staging.

Conclusion: We had established a new nomogram to predict the 1-, 3-, 5-year OS of elderly patients with MBT. This predictive model can help doctors and patients develop treatment plans and follow-up strategies.

Primary intra- and extradural extramedullary mesenchymal chondrosarcoma with isolated punctate calcification: case report and literature review

Background

Mesenchymal chondrosarcoma (MCS) is an ultra-rare, high-grade subtype of chondrosarcoma affecting both bone and soft tissues. Extra-skeletal MCS rarely occurs in intra- and extradural regions.

Case presentation

We presented a case of intraspinal dumbbell-shaped MCS at the T12-L2 level with isolated punctate calcification in a 19-year-old male complaining of progressive lower back pain. Surgical treatment for removal of the tumor was performed. The postoperative pathological result confirmed MCS. The patient showed symptomatic improvement and follow-up MRI showed no evidence of recurrence or metastasis for nearly 1 year after surgery.

Conclusions

CT and MRI play an important role in differential diagnosis for intraspinal MCS. MCS should be added to the differential diagnosis of intraspinal dumbbell-shaped tumors, especially when radiological examinations reveal punctate calcification in a homogeneous enhanced tumor without dural tail sign. However, the final diagnosis depends on histopathological results. Despite the good prognosis of intraspinal MCS, close follow-up after operation is still necessary.