Rare Pulmonary Artery Sarcoma Shows Distinct Imaging Signature in 101-Patient Multicenter Study

Primary pulmonary artery sarcoma is a rare malignancy that is frequently mistaken for pulmonary thromboembolism, and a new multicenter retrospective study has now assembled one of the largest imaging cohorts of the disease to date. The research, published in Cancer Imaging, analyzed 101 patients treated between January 2015 and January 2025, combining computed tomography pulmonary angiography (CTPA) with magnetic resonance imaging and PET/CT to build a more complete picture of how this tumor presents across imaging modalities.

The cohort included 55 female patients, with a median age of 53 years. On CTPA, the sarcoma showed a characteristic pattern: complete intraluminal filling defects with expansive growth appeared in 93.1 percent of cases, and proximal bulging or a lobulated sign was present in 91.1 percent. Distal aneurysmal dilatation occurred in 47.5 percent of patients, while saddle-shaped filling defects, a feature that can closely mimic a large thromboembolus, were observed in 35.6 percent.

MRI added complementary information in the 31 patients with available studies. The tumors showed median native T1 and T2 values of 1483 milliseconds and 82 milliseconds respectively, heterogeneous enhancement in 90.3 percent of cases, and the Wall Eclipsing Sign in 35.5 percent.

Metabolic imaging further strengthened the diagnostic picture. Among 29 patients with available PET/CT, the tumors showed avid uptake of 18F-FDG, with a median maximum standardized uptake value of 8.10. Pathological examination confirmed that intimal sarcoma was the predominant subtype, accounting for 91 of the 101 patients, or 90.1 percent.

The study also examined treatment outcomes in a smaller follow-up cohort. Follow-up data were available for 33 of the 101 patients, of whom 22 underwent surgery. Twenty-one of those surgical patients achieved complete macroscopic resection, classified as R0 or R1, representing 95.5 percent of the surgery cohort, and one patient underwent partial resection. Perioperative complications occurred in 36.4 percent of the follow-up cohort, and the 30-day mortality rate was 9.1 percent.

In the exploratory survival analysis of this follow-up cohort, surgical treatment was associated with longer overall survival than non-surgical treatment. Median overall survival was 56.1 months in the surgical group compared with 14.1 months in the non-surgical group, a difference that reached statistical significance with a log-rank P value of 0.015. Univariable Cox regression analysis yielded a consistent finding, with a hazard ratio of 0.33 and a 95 percent confidence interval of 0.13 to 0.84, corresponding to a P value of 0.021.

Notably, baseline CTPA features were not significantly associated with overall survival, either in log-rank tests or in univariable Cox analysis. The authors suggest that this means radiological complexity alone should not preclude surgical evaluation, although they emphasize that prospective validation is needed before such a conclusion can be considered firm. The survival analysis was explicitly exploratory and limited to the 33 patients with available follow-up data, a small subset of the full imaging cohort, so the estimates carry considerable uncertainty.

The study’s methods reflected its retrospective, multicenter design. Baseline CTPA studies, available MRI and PET/CT examinations, surgical outcomes, and complications were assessed for all included patients. Overall survival was analyzed using the Kaplan-Meier method and the log-rank test, while univariable and multivariable Cox regression models were used to estimate hazard ratios with 95 percent confidence intervals. The analysis was restricted to patients with available follow-up data, and the imaging features were characterized at baseline rather than during treatment.

For clinicians, the practical message is that integrating CTPA with MRI and PET/CT facilitates recognition of this rare tumor.

The authors caution that their findings come from a limited follow-up cohort and that prospective validation is needed.

Subject of Research: Multimodality imaging features and exploratory survival analysis of primary pulmonary artery sarcoma

Article Title: Multimodality imaging features of primary pulmonary artery sarcoma and exploratory survival analysis: a multicenter retrospective study

Article References: Liu, A., Liu, X., Song, Y., Xi, L., He, P., Du, J., Zhang, S., Guo, Y., Yu, H., Li, H., Liu, H., Guo, X., Yu, H., Li, F., Peng, D., Deng, Y., Tao, X., Ma, R., Fu, L., … Liu, M. (2026). Multimodality imaging features of primary pulmonary artery sarcoma and exploratory survival analysis: a multicenter retrospective study. Cancer Imaging. https://doi.org/10.1186/s40644-026-01141-6

Image Credits: AI Generated

DOI: 10.1186/s40644-026-01141-6

Keywords: pulmonary artery sarcoma, CTPA, MRI, PET/CT, intimal sarcoma, misdiagnosis, pulmonary embolism, surgery, overall survival, retrospective study, radiology, oncology