Lung carcinoma is the leading cause of death related to cancer in both men and women through-out the world. Primary lung carcinoma spreading to pulmonary vessels is quite rare and only few individual cases have been reported in the medical literature.1) The prognostic significance of pulmonary vessel invasion by lung carcinoma is unclear and the treatment is challenging. We aim to describe a case of a primary lung carcinoma infiltrating into both the pulmonary arteries and the left atrium who presented to us with dyspnea and hemoptysis.

A 50-year-old male presented to us with effort dyspnea of NYHA functional class II for last 3 months. He also had one episode of hemoptysis one month back. General examination was significant for suboptimal nutrition and a prominent jugular venous pulsation. Cardiac auscultation revealed a grade III/VI pansystolic murmur at left 3rd and 4th parasternal region which was increasing in intensity on inspiration. Also there was a grade III/VI ejection systolic murmur in the pulmonary area. Electrocardiogram had evidence of right ventricular pressure overload. Chest X-ray (Fig. 1) showed a large opaque shadow in the upper and middle zone of the left lung which could not be separated from the cardiac silhoute. Also the left hemi-diaphragm was higher than the right hemi-diaphragm. Two dimensional (2D) trans thoracic echocardiography (TTE) showed a large extra-cardiac, echo-dense, non mobile mass near the right ventricular outflow and pulmonary artery region (Fig. 2A and B, Supplementary movie 1 and 2) causing severe extrinsic compression of both the right and the left pulmonary artery resulting into severe high pressure tricuspid regurgitation with a peak velocity of 4.2 m/sec (Fig. 2C and D). There was also an abnormal mass visualized into the left atrium in the parasternal long axis view (Fig. 2A, Supplementary movie 3). Three dimensional (3D) TTE clearly delineated the surface characteristics and the anatomical relationship of the mass in the left atrium (Fig. 3C and D, Supplementary movie 4 and 5) as well as stenosis of the right pulmonary artery caused by the mass (Fig. 3B). Evaluation by multidetector computed tomography (MDCT) showed a large mass (measuring 8.0 × 8.0 × 7.0 cm) in the upper left pulmonary region encroaching upon and causing severe extrinsic compression of both the pulmonary arteries (Fig. 4A and B). The same mass was infiltrating into the left atrium in the form of a pedunculated growth (Fig. 4C and D). Computed tomography guided biopsy revealed non-small cell lung carcinoma (NSCLC) and patient was graded as T4 NSCLC due to in-growth into left atrium. He was started on cisplatin and paclitaxel based chemotherapy, but patient succumbed one month later due to a large bout of hemoptysis.

Acquired pulmonary artery stenosis is rarely found after childhood1) and a tumor causing bilateral pulmonary artery compression and involvement of the left atrium is rarely reported. The differential diagnosis for the etiology of the extrinsic pulmonary artery compression includes malignant tumors, infection, cyst, and other benign processes leading to fibrosis in the mediastinum. The treatment is directed towards control of the underlying disease. 2D transthoracic echocardiography plays an important role in evaluation of right heart valvular disease.2) The role of 3D echocardiography for evaluation of intracardiac masses is also evolving.3) In the present case, 2D TTE with color Doppler suggested the diagnosis and 3D TTE was complimentary to 2D TTE. The final diagnosis was ultimately made by MDCT with histopathological confirmation.

In short, malignancy is one of the causes of acquired pulmonary artery stenosis in adults and 2D TTE is an important non invasive tool for detection of hemodynamic compromise resulting from the pulmonary flow obstruction. 3D TTE can be useful in evaluation of cases where tumor has an intracardiac extension.