Pulmonary Vascular Disease NetWork Case Puzzler- May 2011

Pulmonary Vascular Disease NetWork Case Puzzler- May 2011

Clinical presentation
A 45-year-old man who was very active and could run up to 100 miles until 2 months prior to presentation started complaining of dyspnea on exertion, reduced exercise capacity, increased fatigue, and a dry cough. He was evaluated and found to have a pulmonary embolus with near occlusion of the main pulmonary artery. He received an infusion of tissue plasminogen activator (TPA) with resolution of this clot, except for some residual clot on the right side. A regimen of enoxaparin was started and transitioned to coumadin. The patient was discharged but presented again with increasing cough 10 days after discharge. His repeat chest CT scan showed an extensive amount of proximal vessel occlusive material in the right ventricular outflow tract/main pulmonary artery extending into both main pulmonary arteries. Chest CT scan also showed small peripheral nodular lesions in the right upper lobe and right middle lobe. He underwent a second infusion of TPA.  His care was then transferred to our hospital.

Medical and surgical history
Unremarkable.

Social history
No history of alcohol or tobacco abuse. No illicit drug abuse. He was married with two children and was an engineer by profession.

Current medications
Enoxaparin, docusate, iron, pantoprazole, coumadin.

Physical examination Temperature, 97.4 F; BP, 179/72; heart rate, 82 bpm; respiratory rate, 12/min; oxygen saturation, 100% on 2 L (by nasal cannula)
General: comfortable at rest; in no acute distress.
HEENT: neck, supple.
PULM: crackles in right upper lung zone; 3/6 bruit over left pulmonary artery
CV: heart sounds regular in rate and rhythm
EXT: no edema on the examination of extremities
NEURO: no focal neurologic deficits
HEP: liver ultrasound showed patent portal and hepatic veins.

Laboratory data
Sodium, 141 mEq/L; potassium, 3.9 mEq/L; BUN, 6 mg/dL; creatinine, 0.7 mg/dL; INR, 1.82; liver function test, normal; WBC, 5.5 X 10⁹/L; hemoglobin, 12.2 g/dL; platelets, 249 X 10⁹/L; D dimmer, 1.66 (0.00 – 0.40 µg/mL); brain naturetic peptide, 91 pg/mL. Hepatitis A, B, and C and HIV 1-2 were nonreactive. Lupus anticoagulant was positive; factor V Leiden, negative. Echocardiogram showed LVEF of 65% to 69%, RV size moderately enlarged, RV hypertrophy, RV function moderately decreased. No pericardial effusion was noted. Right ventricular systolic pressure was 81 mm Hg, right atrial pressure was 10 mm Hg, cardiac output was 4.9 L/min, and cardiac index was 2.4 L/min/m².

Chest CT scan
Large filling defect within main pulmonary artery and extending into right and left pulmonary arteries. The mass originates in the pulmonary outflow tract and is associated with some generalized thickening in this location. There is a mass in the right upper lobe that measures 2.3 cm, suspicious for neoplasm. There is some infiltrate present posterior to it in the posterior segment of the right upper lobe, which was considered nonspecific (Fig 1).

Figure 1. CT scan of the chest with contrast showed a large filling defect within the main pulmonary artery extending into right and left pulmonary arteries.

CT-PET scan did not show uptake in the very large filling defects  that were seen on the contrast-enhanced CT scan. Mild uptake is present within a 2.2-cm nodular density in the lateral right upper lobe (Fig 2).

Figure 2. Top, CT-PET scan revealed a large filling defect in both the right and left proximal pulmonary artery that was noted to be photopenic and showed no uptake. . However, mild to moderate uptake was present in multiple areas in the periphery.	Bottom, CT-PET scan showing mild uptake in the 2.2 cm nodular density in the lateral right upper lobe.

Pulmonary angiogram
Main right and left pulmonary arteries filled with clot, with some clot extending into inferior branches of the right pulmonary artery. Peripheral branches were clear. Obstruction to right pulmonary artery was more severe than left pulmonary artery (Fig 3). Bird’s nest inferior vena cava filter was placed. Unsuccessful attempts were made to biopsy this central mass during the pulmonary angiogram procedure, as this mass could not be seen fluoroscopically, and the biopsy results revealed only blood clots.

Figure 3. Pulmonary angiogram showed main right and left pulmonary arteries filled with clot with some clot extending into inferior branches of the right pulmonary artery. Peripheral branches were clear. There was paucity of vessels in some areas in the periphery.

Cardiac MRI
Demonstrated a large filling defect in the pulmonary artery, extending from the root into both the right and left pulmonary artereries. In some locations, it appears adherent to the wall of the pulmonary artery. There is no invasion of adjacent myocardium and no extension through the wall of the pulmonary artery is seen. After contrast as administered, the majority of the mass does not appear to enhance significantly. However, there is at least one portion at the root of the pulmonary artery that appears to enhance (Fig 4).

Figure 4. Cardiac MRI revealed a large filling defect in the main pulmonary artery, extending from the root into both the right and left pulmonary arteries. In some locations, it appeared adherent to the wall of the pulmonary artery. There was no invasion of adjacent myocardium, and no extension through the wall of the pulmonary artery was seen.

Question: What is the diagnosis?

See the Answer

 

Answer: Pulmonary intimal sarcoma.

Clinical course
The patient successfully underwent pulmonary thromboendarterectomy, and the final diagnosis was pulmonary intimal sarcoma (Fig 5). The patient was referred to an oncologist for further management and follow-up. Following the pulmonary thromboendarterectomy, echocardiogram showed right ventricular systolic pressure of 31 mm Hg. Right ventricle was slightly enlarged with normal function and mildly enlarged right atrium. Left ventricular size and systolic function were normal. Resolution of mass in pulmonary artery with normalization of right ventricular size and almost normalized pressure. Cardiac output increased to 7.7 L/min.

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Figure 5. Pulmonary thromboendarterectomy specimen.

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Postpulmonary endarterectomy perfusion scan showed a dramatic interval improvement in the perfusion to the right lung.The perfusion images were essentially normal.

Postoperative hemodynamic values were as follows: pulmonary artery pressure, 27/7 mm Hg, with mean, 12 mm Hg; right atrial pressure, 8 mm Hg; cardiac output, 6.33 L/min; cardiac index, 3.07 L/min/m².

Normal oxygen saturation at rest was 99%, and, with exercise, no desaturation was noted.

Discussion
Intimal sarcoma of the pulmonary artery is a rare mesenchymal tumor that arises in large vessels and carries a poor prognosis. It usually is misdiagnosed as chronic thromboembolic disease and, in most cases like ours, the definitive diagnosis is made at surgery or at autopsy. This tumor is characterized by local growth with ability to metastasize and potential for embolization. The patient may have a long asymptomatic course that is followed by insidious onset of symptoms of right-sided failure. When the patient experiences symptoms from this tumor, the prognosis is poor, with a life expectancy of 12 to 18 months. Our patient underwent complete resection of the tumor from the pulmonary artery and its branches.

Teaching point
Pulmonary artery sarcoma can masquerade as chronic thromboembolic disease, and this should be included in the differential diagnosis, especially in the presence of pulmonary nodules.

Recommended Reading
1. Fernandez-Golfin C, Escribano P, Cortina J, et al. Management of primary pulmonary artery sarcoma: experience of a single center. Angiology. 2008;59(5):636-639.
2. Gan HL, Zhang JQ, Zhou QW, et al. Surgical treatment of pulmonary artery sarcoma [published online ahead of print April 15, 2011]. J Thorac Cardiovasc Surg.
3. Kaplinsky EJ, Favaloro RR, Pombo G, et al. Primary pulmonary artery sarcoma resembling chronic thromboembolic pulmonary disease. Eur Respir J. 2000;16(6):1202-1204.
4. Kerr KM. Pulmonary artery sarcoma masquerading as chronic thromboembolic pulmonary hypertension. Nat Clin Pract Cardiovasc Med. 2005;2(2):108-112.
5. Levy E, Korach A, Amir G, Milgalter E. Undifferentiated sarcoma of the pulmonary artery mimicking pulmonary thromboembolic disease. Heart Lung Circ. 2006;15(1):62-63.
6. Pavlidis AN, Tsoukas AS, Kallistratos MS, Hesketh G, Manolis AJ. Relapsed pulmonary sarcoma presenting as congestive heart failure [published online ahead of print April 21, 2011]. Neth Heart J.

 

Puzzler submitted by:
Zeenat Safdar, MD, FCCP
Assistant Professor of Medicine
Associate Director, Pulmonary Hypertension Center
Baylor College of Medicine
Houston, Texas
Steering Committee Member, Pulmonary Vascular Disease