CASE 11861 Published on 19.10.2014

Unusual pattern of spread of primary lung cancer


Chest imaging

Case Type

Clinical Cases


La Pietra Pasquale, Sommario Miriam, Parpanesi Roberta, Giombi Andrea.

Ospedale Bentivoglio,
Asl Bologna,
Dipartimento servizi;
Via Marconi
40121 Bentivoglio, Italy;

74 years, male

Area of Interest Lung ; Imaging Technique Conventional radiography, CT, PET-CT, PET, Image manipulation / Reconstruction
Clinical History
A 74-year-old man was admitted to our hospital presenting with fever, cough and moderate dyspnoea.
Imaging Findings
Chest radiograph at admission showed an ill-defined rather round parenchymal consolidation in the right upper lobe interpreted as pneumonia. Ten days later, this had increased in size and within it there were lucencies suggestive of cavitation. A contrast-enhanced CT (CECT) confirmed these findings and showed involvement of the main right pulmonary artery with a large filling defect, suggestive of pulmonary embolism with lung infarction.
Due to clinical deterioration another CECT was performed a few days later showing increase of the parenchymal consolidation and internal cavitation. Despite treatment, there was no improvement in vascular obstruction, raising suspicion of a neoplastic origin of the lesion. A subsequent Positron Emission Tomography (PET CT) revealed fluorodeoxyglucose (FDG) uptake in the consolidation of the right upper lobe and within the right pulmonary artery. Transbronchial needle aspiration revealed a small cell tumour, which was considered surgically unresectable. The patient was further treated with chemotherapy.
The obstruction of pulmonary arteries with reduction or blockage of blood supply to lung is commonly caused by blood clots, air bubbles or fat particles into the lumen of pulmonary vessels and is known as pulmonary embolism (PE) [1-2].
PE can also be caused by growth of a neoplasm inside the vascular lumen such as angiosarcoma, metastatic emboli or primary lung cancer. The vascular invasion by lung carcinoma is frequent microscopically, while a polypoid growth of the cancer into the lumen of pulmonary artery is very rare [3-5].The mechanical obstruction and the pulmonary arterial constriction by humoral or reflex mechanisms causes an increase of the vascular resistance with right ventricular failure that may rapidly progress to cardiac failure and death. The lung infarction occurs rarely, due to the dual pulmonary bloodstream and the oxygenation of the pulmonary tissues via ventilation [6].
Unlike common PE that can have an acute onset with severe haemodynamic failure, PE related to malignancy has a more insidious onset with nonspecific symptoms such as chest pain, shortness of breath, progressive hypoxia, fever, cough, haemoptysis. Imaging is crucial for diagnosis. Chest radiograph is generally negative, can be useful to rule out other diseases or may reveal an enlarged pulmonary artery (Fleishner sign), regional oligaemia (Westermark's sign) and pleural effusion. A wedge-shaped pleural-based opacity (Hampton's hump) is suggestive of lung infarction.
CECT is the best imaging test directly detecting emboli within the vessels.
This may appear, on the imaging planes perpendicular to the blood vessel, as a thin rim of contrast around a central filling defect (polo mint's sign) or as a linear filling defect surrounded by contrast material (railway track sign) on the longitudinal images. Other findings are abrupt narrowing or complete obstruction of the pulmonary arteries [7].
Frequently the tumoral obstruction is misdiagnosed as the more common thromboembolism. Differentiating features between the two types may be the following: thromboembolic PE filling defects are usually multiple, whereas in tumour involvement it is a solitary finding.
Expansion of pulmonary artery and enhancement of the intraluminal lesion secondary to its vascularization favour malignancy.
Part of the parenchymal consolidation was partly due to a post-obstructive necrotic pneumonia, however, the FDG uptake within the tumour also suggested spread of the tumour.
Treatment may include surgical resection combined with postoperative chemotherapy or chemotherapy combined with radiotherapy. In any case the treatment is challenging and decision and prognosis greatly depend on possible arterial invasion that is generally an ominous prognostic sign [5-8].
Differential Diagnosis List
Primary lung cancer
Lung infarction
Final Diagnosis
Primary lung cancer
Case information
DOI: 10.1594/EURORAD/CASE.11861
ISSN: 1563-4086