Pulmonary artery sarcoma masquerading as chronic pulmonary thromboembolism

Imaging-Guided Percutaneous Endovascular Biopsy Applied in Patients with Pulmonary Artery Masses: A Review

INTRODUCTION

Pulmonary artery (PA) masses are rare. Distinguishing PA tumours from embolism is sometimes difficult, and surgical biopsy is expensive and risky. We aimed to evaluate the efficacy of imaging-guided percutaneous endovascular biopsy (PEB) for obtaining tissues for histological diagnosis.

METHODS

We searched Cochrane, Medline, Embase, and Web of Science for PEB trials involving patients with PA masses, published from the inception of the database until August 2023.

RESULTS

We retrospectively reviewed 33 studies including 87 patients (median age 55 ± 69.3 years, 44 men) with PA masses who underwent a total of 110 PEBs. Of these patients, 34.5% (n = 38) underwent PEB-catheter aspiration (PEB-CA), 50.9% (n = 56) underwent PEB-forceps biopsy (PEB-FB) and 2.7% (n = 3) underwent PEB-directional atherectomy (PEB-DA). The most common histological aetiology of PA masses was mesenchymal tumours (n = 67, 75.9%). Tumour embolism (n = 6, 6.9%) and pulmonary embolism (n = 3, 3.4%) were the second and third most common types of PA masses, respectively. The technical success rates of PEB-CA, PEB-FB and PEB-DA were 92.1%, 94.6% and 100% (p = 0.796), respectively. Histopathological analysis provided clinical diagnostic success rates of 44.7%, 85.7% and 100% for PEB-CA, PEB-FB and PEB-DA (p < 0.001), respectively. In pairwise comparison, PEB-FB had a higher success rate in pathological diagnosis than PEB-CA (p = 0.000). Apart from one patient suffering from haemorrhagic cardiac tamponade, no other complications occurred.

CONCLUSION

Imaging-guided PEB is a safe and effective technique for the early pathological diagnosis of PA masses.

Results of surgical treatment of pulmonary artery sarcomas: Does histology affect survival?

Background

In this study, we aimed to describe our experience with primary pulmonary artery sarcoma in patients who underwent pulmonary endarterectomy and to evaluate clinical features, treatment, outcomes, and survival rates according to the histological subtypes of this malignant disease.

Methods

Between March 2011 and May 2022, a total of 13 patients (7 males, 6 females; mean age: 52.6±13.0 years; range, 30 to 69 years) who underwent pulmonary endarterectomy and diagnosed with a pulmonary artery sarcoma were retrospectively analyzed. The diagnosis was confirmed histopathologically in all patients. Data including demographics, clinical characteristics, intra- and postoperative complications, length of hospital stay, morbidity, mortality, and short-term and long-term outcomes were recorded. Operative mortality was defined as death in the hospital or within 30 days of surgery.

Results

Mortality was observed in one patient due to massive hemoptysis. Morbidity developed in two patients due to acute respiratory distress. Pulmonary vascular resistance improved significantly from 508 dyn/s/cm-5 to 191 dyn/s/cm-5 (p<0.004). All patients received chemotherapy following surgery. Median followup was 14 months. Median survival for the entire series was 18 months. One-year and three-year survival rates were 60.6% and 30.3%, respectively. Median survival for leiomyosarcomas (n=6) was seven months, while it was 44 months for intimal sarcomas (p=0.004). Three-year survival was 66.7% for intimal sarcomas and 0% for leiomyosarcomas.

Conclusion

Pulmonary artery sarcoma may mimic chronic thromboembolic pulmonary hypertension. Patients with a suspected diagnosis of pulmonary artery sarcoma should be referred to expert pulmonary endarterectomy centers for surgery where a multidisciplinary team is available. Pulmonary endarterectomy has both diagnostic and therapeutic value and may improve survival and quality of life. Patients with intimal sarcoma have longer survival compared to those with leiomyosarcoma.

Improving the imaging diagnostic strategy for pulmonary artery masses based on 18F-FDG PET/CT integrated with CTPA

OBJECTIVE

To evaluate the diagnostic accuracy of computed tomography pulmonary angiography (CTPA) and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for pulmonary artery (PA) masses.

METHODS

Of 2889 patients with PA filling defects of PA on CTPA, 79 consecutive patients suspicious for PA malignancy who subsequently underwent ¹⁸F-FDG PET/CT were enrolled. All masses were diagnosed on the basis of pathological findings or clinical imaging follow-up. For each mass, morphological CT signs, standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on ¹⁸F-FDG PET/CT were used as diagnostic markers.

RESULTS

Expansive growth, irregular margin, invasion, CT contrast uptake, and wall eclipse sign were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of no more than 4 CT signs did not accurately discriminate between the natures of masses. Mean SUVmax, SUVmean, MTV, and TLG values were significantly higher in malignant masses compared to those in benign masses. The diagnostic accuracy of ¹⁸F-FDG PET/CT parameters (SUV, MTV, and TLG) was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, SUVmax > 3.4 significantly increased the identification of malignancies.

CONCLUSIONS

CTPA is a useful imaging modality for diagnosing PA masses, especially when at least 5 abnormal CT signs are identified. Similarly, ¹⁸F-FDG PET/CT accurately identified malignant masses and provided additional valuable information on diagnostic uncertainties after CTPA.

Multimodal Approach of Isolated Pulmonary Vasculitis: A Single-Institution Experience

BACKGROUND

Isolated pulmonary vasculitis (IPV) is a single-organ vasculitis of unknown etiology and may mimic chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to review our clinical experience with pulmonary endarterectomy in patients with CTEPH secondary to IPV.

METHODS

Data were collected prospectively for consecutive patients who underwent pulmonary endarterectomy and had a diagnosis of IPV at or after surgery.

RESULTS

We identified nine patients (six female, median age 48 (23-55) years) with IPV. The diagnosis was confirmed after histopathological examination of all surgical materials. The mean duration of disease before surgery was 88.0 ±70.2 months. Exercise-induced dyspnea was the presenting symptom in all patients. Pulmonary endarterectomy was bilateral in six patients and unilateral in three. No mortality was observed, however, one patient had pulmonary artery stenosis and stent implantation was performed. All patients received immunosuppressive therapies after surgery. Mean pulmonary artery pressure decreased significantly from 30(19-67) mm Hg to 21(15-49) mm Hg after surgery (p <0.05). Pulmonary vascular resistance also improved significantly from 270 (160-1600) to 153 (94-548) dyn/s/cm^-5 (p<0.05). After a median follow-up of 41 months, all but one patient had improved to the New York Heart Association functional class I.

CONCLUSIONS

Isolated pulmonary vasculitis can mimic CTEPH, and these patients can be diagnosed with pulmonary endarterectomy. Furthermore, surgery has not only diagnostic but also therapeutic value for IPV when stenotic and/or thrombotic lesions are surgically accessible. A multidisciplinary experienced CTEPH team is critical for management of these unique patients.

Imaging of Chronic Thromboembolic Disease

Acute pulmonary embolism (PE) is a leading cause of cardiovascular morbidity. The most common long-term complication of acute PE is chronic thromboembolic disease, a heterogenous entity which ranges from asymptomatic imaging sequelae to persistent symptoms. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that can develop in this population and represents the only treatable type of pulmonary hypertension. Recognition of the characteristic findings of chronic pulmonary embolism and CTEPH provides not only diagnostic information, but is also crucial for guiding therapy. The present state-of-the-art review focuses on the multimodality imaging features of chronic pulmonary embolism. Detailed description and illustrations of relevant imaging findings will be demonstrated for ventilation/perfusion (V/Q) scan, CT scan and Dual-Energy CT and MRI and features that distinguish chronic PE from common imaging mimics.

A Rare Pulmonary Artery Sarcoma Masquerading as Pulmonary Embolus

We present the case of a 46-year-old woman with a presumed diagnosis of multiple unprovoked pulmonary emboli. Her cardiorespiratory function continued to deteriorate despite optimal medical therapy. At surgical thrombectomy she was identified to have an intimal soft tissue lesion arising from the right pulmonary artery. This lesion was subsequently diagnosed as a pulmonary artery sarcoma, a rare neoplasm that carries a poor prognosis. It typically presents at an advanced stage with pulmonary vascular obstruction. Surgical debulking is the mainstay of therapy to restore ventilation perfusion mismatching and relieve right-sided heart strain. Median survival of these patients is 20 months with adjuvant chemoradiotherapy. At 9 months after surgery, she has undergone 6 cycles of chemotherapy and has stable disease with no metastases.

Imaging and Surgical Treatment of Primary Pulmonary Artery Sarcoma

Primary pulmonary artery sarcoma is a rare tumor originating from the pulmonary artery tree. Given the low incidence, few centers have reported on more than a handful of cases. Because of its rarity it is also commonly misdiagnosed as pulmonary embolism. Multi-modality diagnostic imaging and recognition of specific imaging characteristics along with a high index of suspicion is required to make the correct diagnosis and expedite treatment. The primary imaging modality for most cardiac tumors such as primary pulmonary artery sarcoma is now MRI. It provides superb spatial resolution as well as functional assessment of the heart and pulmonary circulation. CT imaging also is part of routing imaging and remains as the most pertinent imaging modality to evaluate the lung parenchyma and presence of metastatic disease. Here we review the pertinent imaging modalities and tissue characteristics that facilitate recognition of primary pulmonary artery sarcoma. We also provide a short overview of surgical resection and reconstruction, which is the mainstay therapy, for this rare tumor.

Clinical Characteristics and Treatment Outcomes of Primary Pulmonary Artery Sarcoma in Korea

Pulmonary artery sarcomas (PAS) are rare malignant neoplasms. Right heart failure due to tumour location is the main cause of death in PAS patients. The hemodynamic influence of PAS may effect prognosis, but this has not been proven. We aimed to identify the clinical characteristics and prognostic factors of PAS in Korea, their association with pulmonary hypertension (PH). PAS patients treated at the Asan Medical Center between 2000 and 2014 were reviewed. We examined demographic characteristics, diagnostic and treatment modalities. Potential prognostic factors were evaluated by univariate and multivariate analysis. Twenty patients were diagnosed with PAS. Ten patients were male, the median age was 54 years (range, 33-75 years). The most common symptom observed was dyspnea (65%). The most common histologic type was spindle cell sarcoma (30%). Ten patients had a presumptive diagnosis of pulmonary embolism (PE) and received anticoagulation therapy. Seventeen patients underwent surgery, but only 5 patients had complete resection. Eleven patients received post-operative treatment (chemotherapy = 3, radiotherapy = 5, chemoradiotherapy = 3). PH was observed in 12 patients before treatment and in 6 patients after treatment. Overall median survival was 24 months. Post-treatment PH was associated with poor prognosis (HR 9.501, 95% CI 1.79-50.32; P = 0.008) while chemotherapy was negatively associated with mortality (HR 0.102, 95% CI 0.013-0.826; P = 0.032) in univariate analysis. Post-treatment PH was also associated with poor prognosis in multivariate analysis (HR 5.7, 95% CI 1.08-30.91; P = 0.041). PAS patients are frequently misdiagnosed with PE in Korea. Post-treatment PH is associated with a poor prognosis.

Chronic Thromboembolic Pulmonary Hypertension: the End Result of Pulmonary Embolism

Chronic thromboembolic pulmonary hypertension (CTEPH) occurs when a pulmonary embolism fails to undergo complete thrombolysis leading to vascular occlusion and pulmonary hypertension. Despite the fact that CTEPH is a potential consequence of pulmonary embolism, diagnosis requires a high degree of vigilance as many patients will not have a history of thromboembolic disease. The ventilation perfusion scan is used to evaluate for the possibility of CTEPH although right heart catheterization and pulmonary artery angiogram are needed to confirm the diagnosis. Pulmonary thromboendarterectomy is the first-line treatment for patients who are surgical candidates. Recently, riociguat has been approved for patients with nonsurgical disease or residual pulmonary hypertension despite surgical intervention. This review describes the pathophysiology, risk factors, diagnosis, and management of CTEPH.