Radiological Category Thoracic Cardiovascular Principal Modality 1 CT

Radiological Category: Thoracic Cardiovascular Principal Modality (1): CT Principal Modality (2): General Radiography Case Report 707 Submitted by: Lori A. Jenkins, D. O. Faculty reviewer: Emma C. Ferguson, M. D. University of Texas Medical School at Houston Date accepted: 10 March 2010

Case History 61 year-old female with cough. After diagnostic imaging, the patient received treatment for fungal pneumonia while her cough worsened. Nine months later the patient underwent repeat imaging which showed the following. No significant past medical history Patient reports distant smoking history, quitting over 20 years ago. Previously smoking approximately 5 cigarettes daily for 18 years.

Radiological Presentations Frontal & Lateral radiographs

Radiological Presentations Axial contrast enhanced CT

Radiological Presentations Axial contrast enhanced CT

Radiological Presentations Axial contrast enhanced CT

Radiological Presentations Axial contrast enhanced CT

Radiological Presentations Axial CT with contrast – Lung windows

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Pulmonary embolus • Intravascular metastases • Hilar adenopathy • Pulmonary artery sarcoma

Findings and Differentials Findings: Chest Radiograph: Prominent main pulmonary artery with non-specific airspace opacity in the peripheral left mid lung. CT: Filling defect in the left pulmonary artery with extension into the surrounding lung parenchyma. Differentials: • Pulmonary artery sarcoma • Intravascular metastases • Unilateral hilar adenopathy • Pulmonary embolus

Discussion – Pulmonary Embolus • Incidence: 1 per 1000. Approximately 250, 000 cases annually. • Chest radiograph: Usually normal, with atelectasis and small pleural effusion possibly over time. • Chest CT: Intraluminal filling defect. First diagnostic modality for suspected pulmonary embolus. Brant WE, Helms CA Fundamentals of Diagnostic Radiology, Lippincott Williams & Wilkins, 3 rd Ed. 2006.

Discussion – Intravascular Metastases • Incidence: Most commonly seen with hepatocellular carcinoma or adenocarinoma of the stomach or breast. May also be seen associated with lymphagitic carcinomatosis. • Chest radiograph: Usually normal with small and medium arteries involved. • Chest CT: Beading and multifocal dilation of peripheral subsegmental arteries or peripheral wedge-shaped attenuation secondary to infarction. Seo JB, Jung-Gi I, Goo JM, et al. Atypical Pulmonary Metastases: Spectrum of Radiologic Findings. Radiographics 2001; 21: 403 -417.

Discussion – Unilateral Hilar Adenopathy • Incidence: Most commonly associated with intrathoracic malignancy and about 2% of extrathoracic malignancies such as renal, testicular, head & neck, breast and melanoma. • Chest radiograph: Unilateral hilar enlargement • Chest CT: Enlarged hilar lymph nodes Brant WE, Helms CA Fundamentals of Diagnostic Radiology, Lippincott Williams & Wilkins, 3 rd Ed. 2006.

Discussion – Pulmonary Artery Leiomyosarcoma • Incidence: Exceedingly rare: 0. 001 -0. 03% incidence. Involve central vasculature. Mimics pulmonary embolus. • Chest radiograph: Nonspecific, possible central vascular fullness. • Chest CT: Similar to pulmonary artery filling defects seen with chronic pulmonary embolus. Mattoo A, Fedullo PF, Kapelanski D, Ilowite JS. Pulmonary Artery Sarcoma: A case report of surgical cure and 5 -year follow-up. Chest 2002; 122: 745 -747.

Discussion Pulmonary artery leiomyosarcoma (PAL) is a an exceedingly rare malignancy arising from the smooth muscle in pulmonary arteries or other great vessels. Appears as a filling defect and can be mistaken for a pulmonary embolus. If misdiagnosed and treated with anticoagulation, life-threatening hemorrhage may occur. PALs may show enhancement, are usually unilateral, can extend beyond lumen and may have lobulated contours. Leiomyosarcomas account for approximately 20% of pulmonary artery sarcomas; the rest are undifferentiated or fibrosarcomas. Occurs twice as often in women, with a mean age at diagnosis of 52 years-old. MRI with gadolinium is best at demonstrating inhomogeneous structure with necrosis, hemorrhage and vascularized soft tissue areas.

Diagnosis Left pulmonary artery leiomyosarcoma with invasion of lung parenchyma proven after left pneumonectomy.

References 1. Brant WE, Helms CA. Fundamentals of Diagnostic Radiology. Lippincott Williams & Wilkins, 3 rd Ed. 2006. 2. Seo JB, Jung-Gi I, Goo JM, et al. Atypical Pulmonary Metastases: Spectrum of Radiologic Findings. Radiographics 2001; 21: 403 -417. 3. Mattoo A, Fedullo PF, Kapelanski D, Ilowite JS. Pulmonary Artery Sarcoma: A case report of surgical cure and 5 -year follow-up. Chest 2002; 122: 745 -747. 4. Collins J, Stern EJ. Chest radiography The Essentials. Lippincott, Williams & Wilkins, 2 nd Ed. 2008. 5. Akram K, Silverman ME, Voros S. A Unique Case of Pulmonary Artery Leiomyosarcoma. Journal of the National Medical Association 2006; 98; 12: 1995 -1997. 6. www. Emedicine. com – Lung metastases http: //emedicine. medscape. com/article/358090 -imaging