Pulmonary Artery Intimal Sarcoma versus Pulmonary Artery Thromboembolism: CT and Clinical Findings

Abstract

ObjectiveTo describe CT and clinical findings of pulmonary artery intimal sarcoma (PAIS) compared with those of pulmonary thromboembolism (PTE), to investigate MRI and positron emission tomography (PET)-CT findings of PAIS, and to evaluate the effect of delayed diagnosis of PAIS on survival outcomes.Materials and MethodsTwenty-six patients with PAIS were retrospectively identified and matched for sex, with patients with PTE at a ratio of 1:2. CT and clinical findings of the two groups were compared using Student's t test or chi-square test. The effect of delayed diagnosis on survival was investigated using Kaplan-Meier analysis.ResultsThe most common tumor pattern in PAIS was tumoral impaction. Heterogeneous attenuation, wall eclipse signs, intratumoral vessels, acute interphase angles, single location, presence of lung ischemia, and central location were significantly more common in PAIS than in PTE (all p < 0.01). Levels of D-dimers and brain natriuretic peptide were lower in PAIS than in PTE (p < 0.05). In three patients of PAIS, long inversion time sequence MRI showed intermingled dark signal intensity foci suggestive of intermingled thrombi. All nine patients who had undergone PET-CT displayed hypermetabolism. Diagnosis was delayed in 42.3% of the PAIS patients and those patients had a significantly shorter overall survival than patients whose diagnosis was not delayed (p < 0.05).ConclusionThe characteristic CT and clinical findings of PAIS may help achieve early diagnosis of PAIS and make better survival outcomes of patients. MRI and PET-CT can be used as second-line imaging modalities and could help distinguish PAIS from PTE and to plan clinical management.

Pulmonary Artery Sarcoma Diagnosed by Transbronchial Endosonographic (EBUS-TBNA) Approach

“…PAIS tends to be more common in younger patients with no risk factors for PE. On the other hand, in patients with PAIS, d-dimers is lower so values dd > 2.81 ug/mL FEU, make PAIS less probable [4].…”

“…In the same study PAIS had higher attenuation than PE, which was attributed to the presence of intratumoral vessels. Other reports highlight the high specificity of the wall eclipse sign (tumour eclipsing the wall of the pulmonary artery prior to infiltrating outside the pulmonary artery) which was present significantly in patients with PAIS but none of the patients with PE [4,5].…”

“…It is a very aggressive and dismal prognosis tumor whose challenging diagnostic and management pitfall is that it very closely resembles PE both clinically and radiologically thus leading to important delay until final diagnosis. Those whose diagnosis is delayed have a significantly shorter overall survival than patients whose diagnosis is done in a timely manner However, regardless of the clinical and imaging diagnosis, tissue sampling is warranted before conclusive histopathological diagnosis is confirmed and therapeutic decisions are taken [4]. Most reported cases in the literature focus on surgical biopsy during thoracoscopy, thoracotomy, median sternotomy and other advanced surgical procedures.…”

Mimickers of chronic thromboembolic pulmonary hypertension on imaging tests: a review

“…23 In the laboratory analysis, patients with PAS were found to have lower levels of D-Dimer and BNP than in patients with chronic thromboembolic disease. 24 The presence of multiple mismatched perfusion defects on a VQ scan ( Fig. 3) and pulmonary arterial filling defects on a CTPA can mimic CTEPH.…”

“…Also, post-gadolinium MRA can demonstrate delayed heterogeneous enhancement of the PAS, which is not seen in avascular lesions like thromboembolism. 24 Transthoracic echocardiography may show the presence of pulmonary regurgitation secondary to involvement of the leaflets by the tumor. A transesophageal echocardiogram is also a valuable tool in identifying tumor invasion into the arterial wall.…”