Diagnostic usefulness of 18F-FDG PET/CT in the differentiation of pulmonary artery sarcoma and pulmonary embolism

The diagnostic value of [18F]FAPI-42 PET/CT for pulmonary artery masses: comparison with [18F]FDG PET/CT

OBJECTIVES

To investigate the potential utility of [18F]fibroblast activation protein inhibitor (FAPI) positron emission tomography/computed tomography (PET/CT) for evaluating pulmonary artery (PA) masses, and compare it with [18F]fluorodeoxyglucose (FDG) PET/CT.

METHODS

Participants with clinically suspected PA malignancy were prospectively enrolled and underwent dual-tracer PET/CT ([18F]FAPI-42 and [18F]FDG) imaging. Visual analysis and semi-quantitative parameters were compared between the two types of radiotracers. The tissue specimen underwent immunohistochemical staining to verify FAP expression in the tissue.

RESULTS

Thirty-three patients (18 males/15 females; mean age 53.1 ± 15.4 years) were enrolled. All 21 patients with malignant PA masses were FDG-positive (100%), whereas 20 out of 21 patients were FAPI-positive (95.2%). All 12 patients with benign PA masses were both negative in FDG and FAPI PET. The mean maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR) of FAPI and FDG in malignant PA masses were significantly higher than those of benign masses. Although there was no significant difference in SUVmax between FDG and FAPI in malignant PA masses (11.36 vs. 9.18, p = 0.175), the TBR (liver) and TBR (left ventricle) were more favorable for FAPI than for FDG (13.04 vs. 5.17, p < 0.001); (median: 7.75 vs. 2.75, p = 0.007). Immunohistochemical analysis (n = 16) validated that the level of FAP expression corresponded strongly to the uptake of FAPI in PET/CT scans (rs = 0.712, p = 0.002). For clinical management, FAPI PET found more metastatic lesions than FDG PET in 4 patients, with 2 patients upgrading and 1 patient changing treatment decisions.

CONCLUSIONS

FAPI PET/CT is feasible in the diagnosis of PA masses. Although not superior to FDG PET/CT, FAPI PET/CT showed better target-to-background contrast.

CLINICAL RELEVANCE STATEMENT

This study found that FAPI PET/CT is not superior to FDG PET/CT in diagnosing PA masses, but FAPI PET/CT displays better target-to-background contrast and more positive lesions, which may help improve disease management.

KEY POINTS

Pulmonary malignancies lack specificity in clinical manifestations, laboratory tests, and routine imaging examinations. FAPI PET/CT is not diagnostically better than FDG PET/CT but displays better target-to-background contrast and more positive lesions. Dual-tracer PET/CT ([18F]FAPI-42 and [18F]FDG) imaging improves clinical management of pulmonary artery masses.

Case report: Pulmonary artery sarcoma diagnosed through rare brain metastases

We present the case of a 33-year-old male referred across several hospitals because of suspected chronic thromboembolic pulmonary hypertension (CTEPH). Initially admitted in October 2022 for a recurrent, severe cough and diagnosed with CTEPH, he received anticoagulant therapy. However, his symptoms worsened, necessitating a transfer to another facility for thrombolysis treatment. Following an episode of syncope, an MRI scan revealed a metastatic brain tumor. Subsequently, he experienced a third transfer to our hospital, emergency surgery was performed to alleviate cerebral edema and excise a lesion in the left frontal lobe. Postoperative pathology was inconclusive, but a multidisciplinary team meeting, aided by experienced radiologists, eventually confirmed a diagnosis of pulmonary artery sarcoma (PAS) with systemic metastases. This case underscores the necessity of promptly ruling out PAS in patients presenting with significant emboli in the central pulmonary arteries and suggests early referral to specialized centers for suspected cases.

Massive primary pulmonary artery rhabomyosarcoma: A case report

BACKGROUND

Pulmonary artery sarcomas (PAS) are rare tumours causing an insidiously progressive obstruction of the pulmonary circulation. The clinical presentation is often indistinguishable from chronic thromboembolic pulmonary hypertension (CTEPH). However, the atypical appearance of a heterogeneous filling defect in CT pulmonary angiography (CTPA) should prompt further investigation.

CASE PRESENTATION

A previously healthy young man presented with massive haemoptysis, acute respiratory distress, and progressive exertional dyspnea since the year before. Echocardiography demonstrated severe right ventricular dysfunction and highly probable pulmonary hypertension. CTPA revealed an extensive filling defect with an appearance concerning PAS. Due to syncopal episodes at rest, the patient underwent urgent pulmonary artery endarterectomy (PEA). A massive tree-like tumour was excised as a result. Post-operatively, reperfusion injury and refractory pulmonary oedema mandated extracorporeal membrane oxygenation (ECMO). Unfortunately, ECMO was complicated with massive haemolysis and acute kidney injury. The patient succumbed to multi-organ failure. Through tissue analysis established a diagnosis of embryonal rhabdomyosarcoma.

DISCUSSION

Unfortunately, the patient had not reached out for his worsening dyspnea. PASs should not be mistaken for a thrombus and anticoagulation should be avoided. The urgent condition precluded biopsy and tissue diagnosis. Similarly, neoadjuvant chemotherapy was not feasible. Post-operatively, reperfusion injury and pulmonary oedema ensued, which mandated ECMO. This complication should be anticipated preoperatively. There is a need for more data on PASs to establish a consensus for management.

Pulmonary arterial sarcoma: A case report

RATIONALE

Pulmonary artery sarcoma (PAS) is a rare malignant tumor primarily originating from the pulmonary artery's intima or subintima. Approximately one-third of cases are classified as undifferentiated type. Its clinical manifestations lack specificity, dyspnea is the main symptom but can also present with chest pain, cough, hemoptysis, and other discomforts, making it prone to misdiagnosis as pulmonary embolism (PE).

PATIENT CONCERNS

A 50-year-old woman was admitted to the hospital with "dyspnea for more than 3 months, aggravated for 2 days," and computed tomography pulmonary angiography suggesting "bilateral multiple pulmonary embolisms."

DIAGNOSES

The patient was initially misdiagnosed as PE, and was later definitively diagnosed as undifferentiated pleomorphic sarcoma of the pulmonary artery by pathologic biopsy.

INTERVENTIONS AND OUTCOMES

The patient was initially treated with anticoagulant therapy, but her dyspnea was not relieved. After that, she underwent positron emission computed tomography (PET-CT) and other investigations, which suggested the possibility of PAS, and then she underwent pulmonary endarterectomy to remove the lesion, which relieved her symptoms and was advised to seek further medical attention from the Department of Oncology and Department of Radiotherapy.

LESSONS

PAS can be easily misdiagnosed as PE. If a diagnosis of PE is made, but anticoagulation or even thrombolytic therapy proves ineffective, and there is no presence of PE causative factors such as deep vein thrombosis in the lower extremities, or D-dimer levels are not high, one should be cautious and consider the possibility of PAS.

A primary pulmonary artery sarcoma masquerading pulmonary embolism: a case report and literature review

BACKGROUND

Primary pulmonary artery sarcoma (PAS) is an extremely rare malignant tumor with a poor prognosis. The clinical manifestations of PAS are diverse, including dyspnea, chest pain, cough, and hemoptysis. The poor prognosis is often due to delayed diagnosis caused by similarity in imaging findings with pulmonary thromboembolism (PTE). These cues of diagnosis include the "wall eclipsing sign", lobulated bulging margins, gadolinium enhancement during MRI imaging, and FDG uptake during PET/CT imaging. However, there are still many misdiagnoses.

CASE PRESENTATION

This article reports a woman of reproductive age presenting with a pulmonary artery mass. The computed tomographic pulmonary angiography and positron emission tomography/computed tomography did not show obvious signs of pulmonary artery sarcoma, however, contrast-enhanced echocardiography showed moderate perfusion, which helped differentiate between pulmonary artery sarcoma and pulmonary artery thrombosis, leading to timely surgical treatment.

CONCLUSIONS

PAS is a rare form of cancer that can occasionally be visually similar to PTE on radiographic images. Early diagnosis of PAS is of vital importance to the prognosis of the patients. There are several visual cues that can help differentiate between the two conditions. Additionally, contrast-enhanced echocardiography provides additional information on tumor perfusion, offering another effective approach for a prompt and accurate diagnosis.

Echocardiographic Characteristics of Pulmonary Artery Intimal Sarcoma: Comparison With CTPA

OBJECTIVES

This study examined the echocardiographic characteristics of patients with pulmonary artery intimal sarcoma (PAIS) and compared the results with those from computed tomographic pulmonary angiography (CTPA).

METHOD

Twenty-six (26) patients were diagnosed with PAIS at the current institution during the study period, and 23 were eligible for analysis. Echocardiography and CTPA examinations were performed in all enrolled patients.

RESULTS

The echocardiography results showed that most lesions had expansive growth in the left pulmonary artery (PA); the right PA; or a combination of the left PA, right PA, and main PA, with extension to the pulmonary valve and/or right ventricular outflow tract. These lesions also had distinctive sieve-like echogenic signals. Echocardiography also showed that some lesions had lobulated shapes, were nearly round and echolucent or with calcifications, and moved during imaging. The lesion distribution was similar in CTPA and echocardiography (p=0.361), but CTPA was more sensitive in detection of the complete shape (p=0.023).

CONCLUSIONS

The unique echocardiographic characteristics of PAIS, especially the "sieve sign", could help in the diagnosis of this cancer. Transthoracic echocardiography is a non-invasive technique that appears effective in detecting PAIS.

68 Ga-FAPI-04 Versus 18 F-FDG PET/CT in a Case With Intimal Sarcoma of the Pulmonary Artery

ABSTRACT

Intimal sarcoma of the pulmonary artery is a rare entity, mimicking acute or chronic pulmonary thromboembolism. We describe 68 Ga-FAPI-04 and 18 F-FDG PET/CT findings in a case with intimal sarcoma of the pulmonary artery. The intrapulmonary artery tumor showed inhomogeneously increased FDG and FAPI uptake. Compared with FDG PET/CT, FAPI PET/CT more clearly delineated the tumor partially because of a very low background FAPI activity in the walls of the main pulmonary artery and right ventricle, which showed diffuse FDG uptake.

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.

A Rare Case of Multicentric Primary Pulmonary Artery Sarcoma: Eliminating the Masquerade with Multimodality Imaging

A 68-year-old male presented with a short history of exertional dyspnea and a provisional diagnosis of pulmonary thromboembolism was made. However, chest radiograph and further investigations in the form of computed tomography pulmonary angiogram, magnetic resonance imaging of thorax, and whole body fluorodeoxyglucose (FDG) positron emission tomography-computed tomography revealed a large mass arising from the distal left pulmonary artery extending into adjacent lung and another lesion near the root of the main pulmonary artery, both of which showed post-contrast enhancement and intense FDG uptake. Tissue sampling by transthoracic computed tomography-guided biopsy and immunohistochemistry confirmed the diagnosis of pulmonary artery angiosarcoma. Here, we present such a case of very rare occurrence which, in view of multicentricity and substantial extension into adjacent lung, is the first of its kind to be reported, to the best of our knowledge.

Clinical utility of 18F-FDG PET/CT imaging in patients with pulmonary artery sarcoma

Background

Pulmonary artery sarcoma (PAS) is a rare and fatal malignancy. Due to the lack of specific clinical and radiological features, PAS is always misdiagnosed as pulmonary thromboembolism (PTE). This study aimed to investigate ¹⁸F-FDG PET/CT in distinguishing PAS from PTE, and analyze its correlation with clinical and radiological findings and outcome of PAS.

Methods

Clinical, contrast-enhanced CT, and ¹⁸F-FDG PET/CT characteristics of 14 patients with PAS and 33 patients with PTE were retrospectively reviewed. The correlation between PET/CT metabolic parameters vs. clinical and CT findings was investigated in patients with PAS. The overall survival (OS) was analyzed in PAS patients.

Results

The SUVmax of PAS (median: 8.0, range 3.0–17.2) was significantly higher than PTE (1.8[0.8–3.7]) (P < 0.001), and at a cutoff value of 2.9, the sensitivity and specificity were 100.0% and 93.9%, respectively. Compared with PTE, PAS more frequently occurred in younger population (P = 0.011), involved pulmonary trunk (P < 0.001), and displayed higher enhanced CT (P < 0.001) and ΔCT (enhanced CT compared to non-enhanced CT) (P < 0.001) values. SUVmax of PAS was associated with tumor staging (P = 0.022) and enhanced CT (P = 0.013) and ΔCT (P = 0.005) values. The median OS of PAS patients was 10.5 months, and 12-month and 24-month OS rates were 58.0% and 12.0%, respectively. Only D-dimer level (P = 0.038) and tumor staging (P = 0.019) were associated with OS.

Conclusions

Most PAS displayed high glucometabolism, and SUVmax of ¹⁸F-FDG PET/CT was useful in distinguishing PAS from PTE.

Pulmonary artery sarcoma: An important mimic of pulmonary embolism-Case reports and literature review

Pulmonary artery intimal sarcoma (PAIS) is a rare malignancy which closely mimics acute or chronic pulmonary thromboembolism. There are clinical and radiological characteristics which may raise suspicion of this important differential diagnosis. These include disproportionately low d-dimer, troponin T or NT-proBNP, as well as characteristic findings on CT pulmonary angiography such as the 'wall eclipsing sign' and an non-dependent position of filling defects in the large arteries. Prompt diagnosis avoids inappropriate anticoagulation and facilitates early surgical management which may improve prognosis. There is emerging evidence of an effective treatment paradigm with surgical resection and adjuvant chemotherapy. We present two cases of PAIS diagnosed at a single centre within a 2-year period. We review the literature and demonstrate the features at presentation in our cases which were suggestive of the diagnosis.

PET-Based Imaging with 18F-FDG and 18F-NaF to Assess Inflammation and Microcalcification in Atherosclerosis and Other Vascular and Thrombotic Disorders

Positron emission tomography (PET) imaging with ¹⁸F-fluorodeoxyglucose (FDG) represents a method of detecting and characterizing arterial wall inflammation, with potential applications in the early assessment of vascular disorders such as atherosclerosis. By portraying early-stage molecular changes, FDG-PET findings have previously been shown to correlate with atherosclerosis progression. In addition, recent studies have suggested that microcalcification revealed by ¹⁸F-sodium fluoride (NaF) may be more sensitive at detecting atherogenic changes compared to FDG-PET. In this review, we summarize the roles of FDG and NaF in the assessment of atherosclerosis and discuss the role of global assessment in quantification of the vascular disease burden. Furthermore, we will review the emerging applications of FDG-PET in various vascular disorders, including pulmonary embolism, as well as inflammatory and infectious vascular diseases.

Pulmonary valve sarcoma in patient with coronavirus disease of 2019 (COVID-19), mimicking pulmonary thromboembolism, a very rare case

Pulmonary artery and pulmonary valve sarcoma are malignant and very rare vascular tumors with aggressive clinical course and very poor outcomes. Patients affected by coronavirus disease of 2019 (COVID‐19) are at a higher risk for thromboembolism complication. We describe a young woman with a history of coronavirus pneumonia and progressive dyspnea, hemodynamic disturbance, edema with initial evaluation, and clinical diagnosis of pulmonary thromboembolism. But further imaging study and pathology demonstrated giant sarcoma of pulmonary valve, obstructing pulmonary valve and extending to right ventricular outflow tract and main of pulmonary artery.

Dual-Energy CT for Pulmonary Embolism: Current and Evolving Clinical Applications

Pulmonary embolism (PE) is a potentially fatal disease if the diagnosis or treatment is delayed. Currently, multidetector computed tomography (MDCT) is considered the standard imaging method for diagnosing PE. Dual-energy CT (DECT) has the advantages of MDCT and can provide functional information for patients with PE. The aim of this review is to present the potential clinical applications of DECT in PE, focusing on the diagnosis and risk stratification of PE.

A 51-year-old man with chronic cough and left hilar prominence

A 51-year-old male in good overall health presented with a dry cough of 5 months' duration. He was working as a long-distance truck driver and was a life-long nonsmoker. He had no associated dyspnoea, wheezing, rhinosinusitis, haemoptysis or syncope, nor constitutional symptoms such as weight loss or fevers. Physical examination and vital signs were normal on presentation. Chest radiographs with posterior–anterior and lateral views are shown in figure 1.

What is the diagnosis of this man with a chronic dry cough and left hilar prominence on chest radiography?https://bit.ly/3fL7QMx

Pulmonary Artery Intimal Sarcoma Diagnosed Preoperatively by Endovascular Biopsy and Treated via Right Pneumonectomy and Pulmonary Arterioplasty

Introduction. Intimal sarcoma is a very rare tumor arising within the intima of the pulmonary artery. Preoperative diagnosis of pulmonary artery sarcoma is difficult, and the tumor is sometimes misdiagnosed as pulmonary thromboembolism. We report a case of pulmonary artery intimal sarcoma successfully diagnosed by preoperative endovascular biopsy and treated via right pneumonectomy and pulmonary arterioplasty. Presentation of a Case. A 72-year-old woman was referred to our hospital with a low-attenuation defect in the lumen of the right main pulmonary artery by computed tomography. Pulmonary artery thromboembolism was suspected, and anticoagulation therapy was administered. However, the defect in the pulmonary artery did not improve. Endovascular catheter aspiration biopsy was performed. Histological examination revealed pulmonary artery sarcoma. The patient was treated with right pneumonectomy and arterioplasty with the use of cardiopulmonary bypass. Discussion. Preoperative biopsy by endovascular catheter is worth considering for a patient with a tumor in the pulmonary artery and can help in planning treatment strategies.

Intimal Sarcoma of the Great Vessels

Intimal sarcomas of the pulmonary artery and aorta are rare entities with a poor prognosis. In many instances, pulmonary artery sarcomas are misinterpreted as acute or chronic pulmonary thromboembolism, whereas aortic intimal sarcomas are often misdiagnosed as protuberant atherosclerotic disease or intimal thrombus. Discernment of intimal sarcomas from these and other common benign entities is essential for the timely initiation of aggressive therapy. The most useful imaging modalities for assessment of a suspected intimal sarcoma include CT angiography, fluorine 18-fluorodeoxyglucose PET, and MRI. The authors discuss the clinical features, current treatment options, characteristic imaging findings, and underlying pathologic features of intimal sarcomas. The authors emphasize imaging discernment of intimal sarcomas and how their differential diagnosis is informed by knowledge of radiologic-pathologic correlation. The most reliable distinguishing imaging features are also emphasized to improve accurate and timely diagnosis. Online supplemental material is available for this article. ^©RSNA, 2021.

Pulmonary Artery Sarcoma With Low 18F-FDG Uptake

ABSTRACT

A 75-year-old man presented with dyspnea for more than 2 months, with blood test showing low platelet count and cardiac ultrasound showing severe pulmonary hypertension (>54 mm Hg). A CT pulmonary angiogram showed a filling defect in the pulmonary trunk, right and left pulmonary arteries, raising the possibilities of pulmonary embolism or artery sarcoma. FDG PET/CT was performed for further evaluation and showed low uptake in the pulmonary wall, which supported the diagnosis of pulmonary embolism. Patient was treated with anticoagulants with no changes on repeated CT pulmonary angiogram. Patient underwent surgery, and histopatological examination revealed a pulmonary artery sarcoma.

Smooth Muscle Conditions of the Chest: A Clinical, Radiologic, and Pathologic Review

Smooth muscle conditions of the chest have diverse clinical and imaging manifestations and may involve nearly every thoracic structure. Differentiation among these conditions requires the integration of clinical, radiologic, and histopathologic data. Histologic examination in conjunction with immunohistochemistry is essential for differentiation from other spindle cell neoplastic mimics. Familiarity with these entities will ensure the inclusion of smooth muscle conditions in the differential diagnosis of thoracic soft tissue lesions and potentially guide the clinician in appropriate management. We review the clinical, imaging, and histopathologic features of thoracic smooth muscle-related conditions organized by the anatomic structures affected.

Acute Findings on FDG PET/CT: Key Imaging Features and How to Differentiate Them from Malignancy

PURPOSE OF REVIEW

To review acute findings commonly encountered during routine clinical FDG PET/CT studies and present key imaging features to differentiate them from malignant counterparts.

RECENT FINDINGS

FDG PET/CT is extensively used in routine clinical practice for oncology patients. Incidental acute findings in patients undergoing FDG PET/CT are increasingly common, and awareness of these findings and their mimics are important in delivering a clinically relevant and accurate radiological report for directing further management.

SUMMARY

This article will review examples of common acute findings encountered during routine FDG PET/CT scans, compare them against examples of FDG-avid malignancy that can mimic these findings and emphasize key imaging findings to differentiate acute findings from their malignant mimics.

Surgical treatment of primary pulmonary artery sarcoma

OBJECTIVE

Primary pulmonary artery sarcoma (PAS) is a rare tumor that originates from the intimal layer of the pulmonary artery or pulmonary valve and has a poor prognosis. The standard treatment for this devastating disease remains unclear. This study aimed to summarize the current standard treatments for PAS.

METHODS

From September 2015 to January 2020, six patients were diagnosed with PAS and underwent pulmonary endarterectomy (PEA) at our department. Their medical records were retrospectively reviewed to analyze the clinical characteristics, histopathological features, and postoperative outcomes. Fourteen articles, each reporting at least 6 cases, identified 201 patients diagnosed with PAS, and 158 patients had detailed treatments and follow-up data.

RESULTS

All of the patients who successfully underwent PEA were alive at follow-up, with a mean survival duration of 11.6 months (7-28 months), and one patient developed recurrence in the right upper lobe lung. Two patients received postoperative chemotherapy. In one patient, the tumor invaded the pulmonary valve.

CONCLUSIONS

PAS resection combined with PEA via the aid of cardiopulmonary bypass and deep hypothermic circulatory arrest could achieve maximal tumor resection in patients without metastatic lesions. An individualized surgery strategy relies on a precise preoperative imaging examination. Moreover, postoperative adjuvant therapy could yield improved survival outcomes.

Intimal angiosarcoma masquerading as retroperitoneal fibrosis

We present a rare case of intimal angiosarcoma arising from the iliac artery with unusual symptoms and signs mimicking retroperitoneal fibrosis (RPF). This 84-year-old male presented with constitutional symptoms, abdominal pain, increased acute-phase reactant levels, impaired renal function and a CT-documented left-sided parailiac soft-tissue mass with unilateral extrinsic ureteric obstruction. Whole-body ¹⁸F-fluorodeoxyglucose positron emission tomography scan showed highly increased FDG-uptake in a horseshoe-like pattern surrounding the left common iliac artery, but no pathologic activity elsewhere. Further diagnostic workup revealed no signs of malignancy. Because of its location, CT-guided biopsy of the mass was precluded. A tentative diagnosis of RPF was made and treatment with Tamoxifen 20 b.i.d. was started. However, his condition gradually deteriorated, eventually succumbing to severe pneumosepsis. Autopsy revealed extensive iliac intimal angiosarcoma with infiltrative expansion to the left ureter and tumor emboli in both lungs. The present case suggests that intimal angiosarcoma should be included in the differential diagnosis of suspected RPF.

Intimal sarcoma of the pulmonary artery without 18F-fluorodeoxyglucose uptake

Primary pulmonary intimal sarcoma is rare. Differentiating it from pulmonary thromboembolism is difficult because of similarities in clinical symptoms and imaging findings. Positron-emission tomography-computed tomography has been useful for diagnosing primary pulmonary intimal sarcoma. We describe a rare case of primary pulmonary intimal sarcoma that showed no abnormal ¹⁸F-fluorodeoxyglucose uptake on positron-emission tomography. We resected the mass and performed right ventricular outflow tract reconstruction. Proper diagnosis is necessary to determine appropriate therapy, Clinicians must consider the possibility of primary pulmonary intimal sarcoma even if imaging findings are inconsistent with the disease.

Primary pulmonary artery sarcoma in the pediatric patient: Review of literature and a case report

Primary pulmonary artery sarcoma (PAS) is extremely rare in children. Nevertheless, distinguishing primary PAS from pulmonary embolism is critical to a child's survival. Primary PAS is commonly misdiagnosed as a pulmonary embolism due to similar presenting symptoms and radiographic findings. However, compared to adults, pulmonary embolism is rare in children, especially in patients who do not have predisposing factors or hypercoagulable state. We present a child with primary PAS which mimicked pulmonary embolism on presentation but eventually was resected and is doing well 5 years after resection. In the absence of predisposing factors or hypercoagulable state, solid tumors such as primary PAS should be considered when assessing a pediatric patient with presumed pulmonary embolism.

Unusual cause of filling defect in pulmonary artery: pulmonary artery sarcoma

Pulmonary artery (PA) sarcoma is an extremely rare malignant tumor of pulmonary artery. It is often misdiagnosed as pulmonary thromboembolism (PTE) because of its clinical and imaging features which are quite similar to PTE. Multimodality diagnostic imaging and recognition of specific imaging characteristics with appropriate clinical suspicion are required to make correct diagnosis. In this report, we present a case of PA sarcoma with imaging and clinical features as well as emphasize significance of using multimodality imaging.

A comprehensive review on the diagnosis and management of intimal sarcoma of the pulmonary artery

Only a few hundred cases of intimal sarcomas of pulmonary artery (ISPA) were reported on the literature. Diagnosis of this rare entity is a challenging dilemma with the need for a high expertise in the radiological and pathological identification of ISPA. Treatment strategies rely initially on an early aggressive surgery aiming for complete surgical resection with clear margins while no clear recommendations guiding the choice for additional drug therapy or radiotherapy exist. In this article, we perform an extensive review of the literature on ISPA with details on the clinical presentation, diagnosis and management strategies. An additional goal of this paper is to make practicing oncologists aware of this rare entity with clear idea on the initial management.

Pulmonary intimal sarcoma involving the pulmonary valve and right ventricular outflow tract: A case report and literature review

INTRODUCTION

Pulmonary artery intimal sarcoma (PAIS) is a rare and highly aggressive tumor, and approximately 80% of pulmonary cases occur in the pulmonary trunk. We report herein a case of retrograde extension of the sarcoma to the pulmonary valve and right ventricle, which is an uncommon manifestation of this lethal tumor.

PATIENT CONCERNS

A 41-year-old woman was initially diagnosed with pulmonary thromboembolism (PTE) and transferred to our hospital.

DIAGNOSIS

Computed tomographic pulmonary angiography (CTPA) showed that there are low-density filling defects in both pulmonary arteries, and the patient was diagnosed with PTE. However, the ultrasonographers considered that the lesion is a space-occupying type that involves the right ventricular outflow tract and pulmonary valve instead of PTE. Postoperative pathology confirmed the diagnosis of PAIS.

INTERVENTIONS

The patient underwent resection of pulmonary artery sarcoma and endarterectomy.

OUTCOMES

During the follow-up via telephone 1 month after discharge, the patient reported to have been feeling well.

CONCLUSION

Owing to the rarity of the disease and its non-specific clinical manifestations, approximately half of the PAIS cases are misdiagnosed or have a delayed diagnosis. Thus, improving our understanding of the disease and facilitating its early diagnosis are essential.

Pulmonary arteries: imaging of pulmonary embolism and beyond

The pulmonary arteries are not just affected by thrombus. Various acquired and congenital conditions can also affect the pulmonary arteries. In this review we discuss cross sectional imaging modalities utilized for the imaging of the pulmonary arteries. Acquired pulmonary artery entities, including pulmonary artery sarcoma (PAS), vasculitis, aneurysm, and arteriovenous malformations, and congenital anomalies in adults, including proximal interruption of the pulmonary artery, pulmonary sling, pulmonary artery stenosis, and idiopathic dilatation of the pulmonary trunk, are also discussed. An awareness of these entities and their imaging findings is important for radiologists interpreting chest imaging.

A case of pulmonary artery sarcoma that was initially mis-diagnosed as pulmonary embolism

Pulmonary artery sarcoma is a rare and highly malignant neoplasm. Early diagnosis and a multidisciplinary approach including surgical treatment and optimal medical therapy could prolong survival. Since the clinical symptoms and imaging findings of pulmonary artery sarcoma mimic pulmonary embolism, definitive diagnosis and surgical intervention are often delayed. In this report, a case of pulmonary artery sarcoma that was initially misdiagnosed as pulmonary embolism is presented.

Value of 18F-FDG PET/CT in differentiating malignancy of pulmonary artery from pulmonary thromboembolism: a cohort study and literature review

To determine the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in differentiating malignancy of pulmonary artery (PA) from pulmonary thromboembolism (PTE) based on a larger number of cases by pooling our cases and those from the literature. Consecutive patients with a PA lesion who had undergone ¹⁸F-FDG PET/CT in our hospital were retrospectively reviewed. Moreover, PubMed, Embase, and Medline were searched for literature reporting individual maximum standardised uptake value (SUV_max) of the malignant PA lesion and/or PTE. ¹⁸F-FDG activity was compared between PA malignancy and PTE by pooling the data from literature and our patients. Receiver operating characteristic curve analysis was performed to determine the ability of SUV_max to differentiate PA malignancy from PTE. From our database, we identified 11 patients with pulmonary artery sarcoma (PAS), and nine cases of PTE. Fifty patients with a malignant PA lesion (40 cases of PAS and 10 cases of tumor embolism) and 22 subjects with PTE were extracted from the literature. In our cases, the SUV_max of PAS (11.1 ± 4.9, range: 5.5-19.9) was significantly higher than that of PTE (1.9 ± 0.6, range: 1.1-3.2; P < 0.001). There was no significant difference in the SUV_max between the literature data and our cases in malignant lesions or in PTE. Based on the pooled analysis of the literature data and our cases (61 cases of malignant lesions and 31 cases of PTE), the area under the curve for SUV_max to differentiate PA malignancy from PTE was 0.996 (95% CI: 0.989-1.000). At a cutoff value of 3.3, the sensitivity, specificity, and accuracy were 98.4%, 96.8%, and 97.8%, respectively. The ¹⁸F-FDG uptake value is an accurate index for determining PA malignancy.

Cytohistological correlation, immunohistochemistry and Murine Double Minute Clone 2 amplification of pulmonary artery intimal sarcoma: A case report with review of literature

Pulmonary artery intimal sarcoma is a rare aggressive intraluminal tumor often misdiagnosed as acute or chronic pulmonary thromboembolism due to its clinical presentation and radiological findings. Thus early diagnosis is very crucial and may improve patient outcome. There is limited literature on diagnosis of pulmonary artery sarcoma by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Herein, we report a case of mass-like lesion in the PA diagnosed on cytological material obtained by EBUS-TBNA with rapid on-site evaluation (ROSE). The aspirate showed pleomorphic malignant spindled cells arranged in loosely cohesive clusters. The intraluminal origin of PAIS was supported by radiographic findings. Subsequently, the patient received preoperative chemotherapy and underwent tumor resection with reconstruction. This report describes the cytomorphologic features of this rare intravascular tumor and demonstrates how limited cytological sample obtained from EBUS-TBNA with ROSE can be triaged efficiently for ancillary studies like immunohistochemistry and MDM2 amplification, thus expediting the management.

Aggressive Surgical Resection of Pulmonary Artery Intimal Sarcoma

Intimal sarcoma of the pulmonary artery is a rare and highly malignant neoplasm. This report describes a case of a 30-year-old woman with an extensive right pulmonary artery tumor who underwent an emergency operation. The tumor was aggressively resected with right pneumonectomy and reconstruction of the right ventricle outflow tract and left pulmonary artery. Although the resected margin at the left pulmonary artery was positive for disease, as confirmed by mouse double minute type 2 homologue staining, she is doing well and remains free of relapse at 16 months after the operation.

Pyogenic granuloma originating in the pulmonary artery

We herein report an unreported case of pyogenic granuloma that originated in the pulmonary artery. A 38-year-old man was urgently hospitalized with dyspnea and back pain. He had been on hemodialysis for 2 years due to chronic renal failure. We performed contrast-enhanced computed tomography and detected a mass occluding the left main pulmonary artery. The maximum standardized uptake value (SUV_max) of ¹⁸F-fluorodeoxy glucose (FDG) in the mass was 4.1. We made a tentative diagnosis of pulmonary artery tumor, and planned an operation. We performed median sternotomy and left anterolateral thoracotomy. As the tumor had not reached the bottom of the left pulmonary artery, we first performed left upper lobectomy. We then performed resection of the pulmonary artery tumor under cardiopulmonary bypass and reconstructed the pulmonary artery with self-pericardium. The pathological diagnosis was pyogenic granuloma. To our knowledge, pyogenic granuloma originating in the pulmonary artery has never been reported before.

Clinical features and surgical outcomes of pulmonary artery sarcoma

OBJECTIVE

Pulmonary artery sarcoma is an exceedingly rare malignancy. There is a lack of consensus regarding its diagnosis and treatment. We reviewed our experience in the surgical management of pulmonary artery sarcoma over an 11-year period.

METHODS

From January 2005 to February 2016, 12 patients with pulmonary artery sarcoma (age 51 ± 14 years, 5 male) underwent surgical treatment at our center. Nine patients (75%) exhibited pulmonary trunk involvement on computed tomography angiography. Six patients (50%) were initially misdiagnosed with pulmonary embolism.

RESULTS

Ten patients underwent pulmonary endarterectomy, and 3 of these patients required additional unilateral pneumonectomy. The remaining 2 patients underwent exploratory thoracotomy. One patient (8.3%) died in the hospital. The median length of postoperative intensive care unit and hospital stay were 1 day (range, 1-15 days) and 8 days (range, 5-21 days), respectively. The median postoperative survival of the total series was 18 months. Patients who received postoperative combined chemo- and radiotherapy were associated with improved survival compared with those who had isolated adjuvant therapy or surgery alone (median survival 28 vs 8 months, P = .042).

CONCLUSIONS

Although pulmonary artery sarcoma has a very poor prognosis, surgical treatment offers a chance for symptom relief and better long-term outcome. Aggressive postoperative adjuvant treatment may be necessary to improve survival.

Disease- and Treatment-related Complication on F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Oncology Practice: A Pictorial Review

F-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is routinely performed in oncology patients for various indications including staging, restaging, recurrence detection, and treatment response evaluation. Many disease- and treatment-related complications can be incidentally detected on PET/CT, which may be due to the complication of radiotherapy, chemotherapy, intervention, or primary tumor itself. Some of these complications could be life threatening and need urgent intervention. Therefore, these incidental findings should be recognized on PET/CT and immediately informed to the treating physicians if required urgent intervention.

An intimal sarcoma of pulmonary artery mimicking pulmonary embolism: a case report and literature review

Pulmonary artery intimal sarcoma is a highly aggressive disease, and is most often misdiagnosed as pulmonary thromboembolism (PTE) due to the similar clinical symptoms and its rarity, which leads to the use of inappropriate treatments such as prolonged anticoagulant therapy. We reported a case of pulmonary artery intimal sarcoma in a patient who was misdiagnosed as having PTE. Pathology after surgery confirmed malignant disease. We concluded that when a patient presents with mild clinical manifestations yet with strong imaging manifestations, pulmonary artery malignancy should be suspected.

Aneurysmal angiosarcoma associated with vascular graft revealed by 18F-FDG-PET imaging

We report a rare case of vascular graft-associated aneurysmal angiosarcoma by ¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography (PET). An 81-year-old male patient, with a prior history of graft interposition 1 year previously, was referred to ¹⁸F-FDG-PET because of an inflammatory syndrome of unknown origin. FDG-PET images revealed a particular pattern of intense circular uptake within the arterial wall (SUVmax = 10) in a popliteal aneurysm and, additionally, a large hypermetabolic mass centered by the graft. Remote hypermetabolisms in lung nodules and pleural thickenings were also detected. The diagnosis of angiosarcoma was ascertained through histopathological analysis of surgical samples. Development of an aneurysmal angiosarcoma at the site of a vascular graft is a rare entity, often misdiagnosed. ¹⁸F-FDG-PET appears to be useful in its detection with a PET pattern of intense circular uptake within the arterial wall. Such finding should lead to the search for distant metastasis.

Primary Pulmonary Artery Intimal Sarcoma Case with Elevated Coagulation Markers

Primary Sarcoma of the Pulmonary Artery (PAS) is a very rare and miserable disease. The clinical signs and symptoms of PAS are non- specific, which usually prevents diagnosis before surgery or autopsy. The current guidelines for the diagnosis and treatment of PAS have not been well established. Several reported cases of PAS have been mistaken for Pulmonary Artery Thromboembolism (PTE), because the clinical signs and symptoms of PAS are non-specific. Elevated coagulation markers are generally absent in PAS and therefore, support a differential diagnosis of PTE. We herein report a patient with PAS who presented with elevated coagulation markers and later showed rapidly improved values mimicking response of PTE to anticoagulant therapy.

Diagnosis of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only potentially curable form of pulmonary hypertension. Rapid and accurate diagnosis is pivotal for successful treatment. Clinical signs and symptoms can be nonspecific and risk factors such as history of venous thromboembolism may not always be present. Echocardiography is the recommended first diagnostic step. Cardiopulmonary exercise testing is a complementary tool that can help to identify patients with milder abnormalities and chronic thromboembolic disease, triggering the need for further investigation. Ventilation/perfusion (V'/Q') scintigraphy is the imaging methodology of choice to exclude CTEPH. Single photon emission computed tomography V'/Q' is gaining popularity over planar imaging. Assessment of pulmonary haemodynamics by right heart catheterisation is mandatory, although there is increasing interest in noninvasive haemodynamic evaluation. Despite the status of digital subtraction angiography as the gold standard, techniques such as computed tomography (CT) and magnetic resonance imaging are increasingly used for characterising the pulmonary vasculature and assessment of operability. Promising new tools include dual-energy CT, combination of rotational angiography and cone beam CT, and positron emission tomography. These innovative procedures not only minimise misdiagnosis, but also provide additional vascular information relevant to treatment planning. Further research is needed to determine how these modalities will fit into the diagnostic algorithm for CTEPH.

Primary pulmonary artery sarcoma: a close associate of pulmonary embolism-20-year observational analysis

BACKGROUND

Primary pulmonary artery sarcoma (PPAS) is a rare tumor that mimics pulmonary thromboembolism (PE). Similarities to PE can delay the diagnosis and misguide the treatment of PPAS. This study aimed to evaluate tumor characteristics and outcome predictors among those diagnosed with PPAS and misdiagnosed as PE.

METHODS

From 1991-2010, 10 PPAS cases were available from the Cleveland Clinic (CC) institutional database and another 381 cases were reported in the literature. Patient characteristics, tumor subtypes, diagnostic testing & timing, interventions and clinical outcomes were analyzed. We also noted effects of misdiagnosis as PE and clinical outcome as a result of inappropriate intervention.

RESULTS

Among 391 confirmed cases of PPAS, the mean age at diagnosis was 52±14 years; 55% were male. The median duration of symptoms prior to diagnosis was 100 [interquartile range (IQR), 30-210] days. Nearly half (47%) of PPAS were originally misdiagnosed as PE including 39% that received thrombolytic and/or anticoagulation therapy. For every doubling of time from symptom onset to diagnosis, the odds of death increased by 46% (OR: 1.46, 95% CI: 1.21-1.82; P<0.001). The odds of death (OR: 2.66, 95% CI: 1.58-4.54; P=0.0003) and occurrence of distant metastasis (OR: 2.30, 95% CI: 1.30-4.15; P=0.049) were increased among those who did not receive chemotherapy but chemotherapy did not impact local recurrence. Those with complete resection had a better survival.

CONCLUSIONS

PPAS has a radiological appearance similar to PE, which makes accurate and timely diagnosis challenging. More rapid diagnosis may lead to earlier, appropriate surgical treatment and improved outcomes, when combined with adjuvant treatment.

Pulmonary Artery Sarcoma Detected on 18F-FDG PET/CT With Unusual Findings

A 32-year-old woman, who presented with "sharp pain" in the right chest for more than 1 month and worsening dyspnea and fever for 10 days, was initially thought to have a pulmonary embolism. Cardiac ultrasound showed an ill-defined echogenic mass within the pulmonary trunk. F-FDG PET/CT was performed for further evaluation. PET/CT showed an intense hypermetabolism in the main, bilateral proximal, and the right main pulmonary arteries, suggesting the presence of a malignant lesion. Biopsy confirmed the lesion as a primary pulmonary artery sarcoma.

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.

[Angiosarcoma mimicking recurrent pulmonary embolism]

INTRODUCTION

Pulmonary artery sarcoma is a rare disease with non-specific symptoms. The clinical and radiological presentation can mimic pulmonary embolism with chronic thromboembolic pulmonary hypertension. Management is essentially surgical but the prognosis remains poor.

CASE REPORT

A patient presented with symptoms of pulmonary embolism. Despite vitamin K antagonist therapy, he suffered from extension of the endovascular defects and his pulmonary hypertension increased. Suspicious results of positron emission tomography suggested the diagnosis of pulmonary artery sarcoma that was confirmed by surgery. However, the outcome was unfavourable, leading to death of the patient.

CONCLUSION

This case reinforces the idea that the clinical and tomodensitometric presentations of pulmonary arterial sarcoma and chronic thromboembolic pulmonary hypertension are similar. The positron emission tomography seems to be a key to distinguishing these two diagnoses.

Endobronchial ultrasound-guided transbronchial needle aspiration of pulmonary artery tumors: A systematic review (with video)

Convex probe endobronchial ultrasound (CP-EBUS) was originally introduced as a diagnostic and staging tool for lung cancer and subsequently utilized for diagnosis of other malignant and benign mediastinal diseases such as melanoma, lymphoma, and sarcoidosis. More recently, CP-EBUS has been successfully used for the visualization and diagnosis of pulmonary emboli and other vascular lesions including primary and metastatic pulmonary artery (PA) tumors. In this review, we will underline the role of EBUS-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of pulmonary arterial tumors such as sarcomas and tumor emboli. We will concisely discuss the clinical applications of EBUS-TBNA and the types of pulmonary arterial tumors and their different diagnostic modalities. We searched the Cochrane Library and PubMed from 2004 to 2014 to provide the most comprehensive review. Only 10 cases of EBUS-TBNA for intravascular lesions were identified in the literature. Although many cases of EBUS and EUS-guided transvascular tumor biopsies were described in the literature, there were no reported cases of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for intravascular tumor biopsies. Except for one paper, all cases were published as case reports.