Pulmonary artery sarcoma: not every filling defect is a pulmonary thromboembolism

Clinical and radiological features of pulmonary artery sarcoma: A report of nine cases

OBJECTIVE

To improve our understanding and facilitate early diagnosis of pulmonary artery sarcoma (PAS).

PATIENTS AND METHODS

The clinical and radiological features of 9 histopathologically confirmed patients with PAS were retrospectively analyzed.

RESULTS

Our PAS cohort consisted of 5 males and 4 females, with insidious presentation, the main symptoms were dyspnea (88.9%), syncope (33.3%), palpitations (22.2%), chest pain (22.2%), hemoptysis (11.1%) and constitutional symptoms, including fever (44.4%), fatigue (55.6%) and weight loss (55.6%). Elevated serum inflammatory markers, including an elevated erythrocyte sedimentation rate, lactate dehydrogenase and C-reactive protein, were recorded in 9 (100%), 7 (77.8%) and 8 (88.9%) patients, respectively. Computed tomography pulmonary angiography (CTPA) indicated that 8 (88.9%) patients had intraluminal defects, appearing as rounded, bulging or lobulated masses that display uneven signal intensification in contract-enhanced scans in the pulmonary arteries (PAs). Three (33.3%) of the patients had metastases outside of the PA. Before surgery, 7 patients had been misdiagnosed as pulmonary thromboembolic diseases (PTD), 2 as others, with mean misdiagnosis duration of 7.2 ± 7.1 months. All patients had received thrombolytic and/or anticoagulation therapy and their diseases progressed until receiving pulmonary endarterectomy.

CONCLUSIONS

The clinical features of PAS that may help to differentiate it from PTD are its insidious onset, constitutional symptoms, increased serum inflammatory marker levels, lack of predisposing factors and unresponsiveness to thrombolytic and/or anticoagulation therapy. Typical CTPA features are crucial for suspicion of PAS. Early biopsy or surgery should be performed to confirm the diagnosis of PAS and improve its prognosis.

Dual-energy CT-based iodine quantification for differentiating pulmonary artery sarcoma from pulmonary thromboembolism: a pilot study

OBJECTIVES

The purpose of this study was to determine whether dual-energy computed tomography (DECT) angiography could differentiate pulmonary thromboembolism (PTE) from pulmonary artery sarcoma (PAS).

METHODS

We prospectively enrolled 19 patients that had a filling defect in the main pulmonary artery on DECT. Six patients who had PAS and underwent DECT were retrospectively enrolled for comparison. Pathological results or follow-up CT after anticoagulation therapy were used to make the final diagnosis. Two investigators measured the following parameters at the filling defect in the main pulmonary artery: CT attenuation density [Hounsfield units (HU)], iodine-related HU (IHU) and iodine concentration (IC, mg/ml).

RESULTS

From a total of 25 patients (M:F = 10:15; mean age, 65 years old), 19 were categorised into the PTE group and six were categorised into the PAS group. The mean HU values were not significantly different between the PTE and PAS groups (45.5 ± 15.9 vs 47.1 ± 9.2 HU; P = 0.776). However, the mean IHU and IC values of the lesions were significantly different between the PTE and PAS groups (10.6 ± 7.2 vs 27.9 ± 9.1 HU; P = 0.004, and 0.61 ± 0.39 vs 1.49 ± 0.57; P = 0.001).

CONCLUSIONS

DECT angiography using a quantitative analytic methodology can be used to differentiate PTE and PAS.

KEY POINTS

• DECT can be useful for differentiation of PAS and PTE. • With quantitative analysis, DECT offers tissue characterisation by detecting lesion parameter increases. • The patients without predisposing factors for PTE can be candidates for DECT.