CASE 11861 Published on 19.10.2014

Unusual pattern of spread of primary lung cancer

Section

Chest imaging

Case Type

Clinical Cases

Authors

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

Ospedale Bentivoglio,
Asl Bologna,
Dipartimento servizi;
Via Marconi
40121 Bentivoglio, Italy;
Email:plapietra@tin.it

Patient

74 years, male

Categories

Area of Interest Lung ; Imaging Technique Conventional radiography, CT, PET-CT, PET, Image manipulation / Reconstruction

Procedure Diagnostic procedure, Computer Applications-Detection, diagnosis, Computer Applications-General, Contrast agent-intravenous, Comparative studies ; Special Focus Embolism / Thrombosis, Inflammation, Cavitation, Neoplasia, Obstruction / Occlusion ;

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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.

Discussion

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

Thromboembolism

Lung infarction

Final Diagnosis

Primary lung cancer

References

[1] Goldhaber SZ. (2004) Pulmonary embolism. Lancet Apr 17;363(9417):1295-305. (PMID: 15094276)

[2] Piazza G1, Goldhaber SZ. (2008) Pulmonary embolism in heart failure. Circulation 2008 Oct 7;118(15):1598-601 (PMID: 18838576)

[3] Parish JM1, Rosenow EC 3rd, Swensen SJ, Crotty TB. (1996) Pulmonary artery sarcoma. Clinical features. Chest Dec;110(6):1480-8. (PMID: 8989065)

[4] Zurick AO 3rd1, Lenge De Rosen V, Tan CD, Rodriguez ER, Flamm SD, Schoenhagen P. (2011) Pulmonary artery intimal sarcoma masquerading as pulmonary embolism. Circulation Sep 6;124(10):1180-1. (PMID: 21900097)

[5] Kamigaki M., Yamazaki K, Tsujino I, Suga M, Sakaue S, Dosaka-Akita H, Nishimura M. (2005) Small cell carcinoma of the lung exclusively localized within the left descending pulmonary artery. Chest Jun;127(6):2273-6. (PMID: 15947349)

[6] Chamsi-Pasha MA, Alraiyes AH, Mamoun I, Alraies MC. (2013) Peripheral opacity on plain chest radiography. Cleve Clin J Med Oct;80(10):621-4 (PMID: 24085806)

[7] Wittram C1, Maher MM, Yoo AJ, Kalra MK, Shepard JA, McLoud TC. (2004) CT angiography of pulmonary embolism: diagnostic criteria and causes of misdiagnosis. Radiographics Sep-Oct;24(5):1219-38. (PMID: 15371604)

[8] Yamaguchi T1, Suzuki K, Asamura H, Kondo H, Niki T, Yamada T, Tsuchiya R. (2000) Lung carcinoma with polypoid growth in the main pulmonary artery: report of two cases. Jpn J Clin Oncol Aug;30(8):358-61. (PMID: 11059342)

Case information

URL:	https://www.eurorad.org/case/11861
DOI:	10.1594/EURORAD/CASE.11861
ISSN:	1563-4086

Figure 1

Chest radiograph

Chest radiograph (frontal) at admission shows an ill-defined rather round consolidation in the right upper lobe.

Chest radiograph (lateral) at admission shows an ill-defined rather round consolidation in the right upper lobe.

Chest radiograph (ten days later) shows interval increase in size of the lesion with internal cavitation.

Figure 2

SECOND CECT

CECT (axial view on lung windowing) shows extensive consolidation of the right upper lobe with internal cavities.

Coronal reformat on lung windowing shows massive consolidation of the right upper lobe with internal cavities.

Sagittal reformat on lung windowing shows massive consolidation of the right upper lobe with internal cavities.

CECT (axial view on mediastinal windowing) shows extensive consolidation of the right upper lobe with internal cavities. The right pulmonary artery is completely filled with thrombus in contiguity with the parenchymal consolidation (red arrow).

Contrast-enhanced coronal reformat on mediastinal windowing shows extensive consolidation of the right upper lobe with internal cavities. The right pulmonary artery is completely filled with thrombus in contiguity with the parenchymal consolidation.

Comparison between unenhanced and enhanced CT show a modest enhancement of the filling defect inside right pulmonary artery. (80 vs 40 U.H.)

Figure 3

PET

PET/CT shows fluorodeoxyglucose uptake in the consolidation of right upper lobe and within the lumen of the right pulmonary artery.

PET/CT shows fluorodeoxyglucose uptake in the consolidation of right upper lobe and within the lumen of the right pulmonary artery.

PET/CT shows fluorodeoxyglucose uptake within the lumen of the right pulmonary artery.

Figure 4

FIRST CECT

CECT (axial view on lung windowing) shows consolidation of the right upper lobe with internal cavitation.

CECT (axial view on mediastinal windowing) shows involvement of the right pulmonary artery involved by a massive thrombus. Note also expansion of the right pulmonary artery.

Coronal reformat on mediastinal windowing shows consolidation of the right upper lobe with internal cavities and the right pulmonary artery being expanded and completely filled by thrombus.

Figure 5

Follow up CECT