Figure 1
Chest X-ray
Chest X-ray shows multiple bilateral nodular opacities (arrows) associated with parenchymal bands
A strange case of pulmonary embolism
SectionChest imaging
Case TypeClinical Cases
AuthorsRobella Mattia1, Cortese Giancarlo2, Bertucci Roberto3
Connected authors
78 years, male
Clinical History
A 78-year-old man, ex-smoker, in treatment with oral anticoagulants for permanent atrial fibrillation was referred for a chest X-ray in order to investigate an episode of haemoptysis, longstanding cough and recurrent bronchitis. A hepatic cyst, probably hydatid in nature, was identified during preoperative assessment for elective cholecystectomy 20 years ago.
Imaging Findings
Chest X-ray (Fig. 1) demonstrated multiple nodular opacities in the right upper lobe.
Contrast enhanced Chest-CT demonstrated the presence of filling defects in the right middle and inferior lobe pulmonary arteries, compatible with embolism (Fig. 2a-b). Lobulated non-calcified opacities in bilateral upper lobes and left lower lobes were noted. These structures correspond to dilated segmental and subsegmental pulmonary arteries, filled with hypodense material (Fig. 2c-d). Echocardiography showed no signs of increased right ventricular pressure.
A partially calcified multi-loculated cyst was detected in liver segments III-IV, compatible with echinococcal cyst, the left hepatic vein could not be delineated (Fig. 2d-e).
PET-CT showed intense uptake of 18F-FDG at the level of the nodes (max SUV 4, 4), without other signs of increased metabolic activity.
Contrast enhanced Chest-CT demonstrated the presence of filling defects in the right middle and inferior lobe pulmonary arteries, compatible with embolism (Fig. 2a-b). Lobulated non-calcified opacities in bilateral upper lobes and left lower lobes were noted. These structures correspond to dilated segmental and subsegmental pulmonary arteries, filled with hypodense material (Fig. 2c-d). Echocardiography showed no signs of increased right ventricular pressure.
A partially calcified multi-loculated cyst was detected in liver segments III-IV, compatible with echinococcal cyst, the left hepatic vein could not be delineated (Fig. 2d-e).
PET-CT showed intense uptake of 18F-FDG at the level of the nodes (max SUV 4, 4), without other signs of increased metabolic activity.
Discussion
Embolization of echinococcal cysts to pulmonary arteries is rare [1-3] and it is caused by hepatic cysts in communication with hepatic veins/inferior vena cava or ruptured cysts in right cardiac chambers [2-5]. Arterial obstruction results from daughter cysts without thrombosis and is classified as a non-thrombotic pulmonary arterial embolism [2, 5]). In our case, infiltration of the left hepatic vein resulted in diffuse pulmonary arterial tree embolization without significant involvement of lung parenchyma.
The main clinical symptoms are cough, dyspnoea, haemoptysis and acute chest pain [6].
Patients with these symptoms are usually referred to the Radiology Department for Chest CT to rule out pulmonary thromboembolism. Enhanced CT demonstrates occlusion and enlargement of the pulmonary arterial tree by hypodense content; the differential diagnosis can therefore be other causes of embolism (thrombotic, septic and neoplastic) and pulmonary artery sarcoma. Clinical history (knowledge of hydatid infestation) and presentation are essential to achieve the correct diagnosis. When hydatid embolism is suspected, radiologists should search for the source of the emboli (hepatic cysts in communication with hepatic veins/vena cava, ruptured cyst in the right cardiac chambers).
MRI can be useful in the differential diagnosis, demonstrating the high signal in the T2-weighted sequences typical of cysts.
Pulmonary artery sarcoma is characterized by low-attenuating filling defect which can extend into lung parenchyma or mediastinum and shows diffuse enhancement.
Cases of hydatid pulmonary embolism are classified into three groups accordig to clinical course: acute fatal cases, subacute pulmonary hypertension cases resulting in death within 1 year and chronic pulmonary hypertension cases [2, 5, 7]. Our patient did not present with severe acute symptoms, neither did he develop chronic pulmonary hypertension. The patient is being regularly followed with echocardiography and shows no signs of increasing right ventricle pressure.
To confirm our diagnosis, the patient underwent VATS biopsy: a diagnosis of gigantocellular fibrogranulomatous nodules with ischemic necrosis and exogenous material referable to fragments of parasites was made.
Treatment of choice for hydatid pulmonary embolism is surgery. Given the anesthesiologic risk due to the permanent atrial fibrillation and the surgical risk of rupture of the artery or of the cyst with anaphylactic shock, we decided on repeated cycles of albendanzole and follow-up, in agreement with the patient.
After 2 years the patient reports a substantial stability in his symptomatology. The last follow up CT (Fig 3a-b) showed an increased extent of pulmonary arterial tree involvement; albendanzole therapy was then again started.
The main clinical symptoms are cough, dyspnoea, haemoptysis and acute chest pain [6].
Patients with these symptoms are usually referred to the Radiology Department for Chest CT to rule out pulmonary thromboembolism. Enhanced CT demonstrates occlusion and enlargement of the pulmonary arterial tree by hypodense content; the differential diagnosis can therefore be other causes of embolism (thrombotic, septic and neoplastic) and pulmonary artery sarcoma. Clinical history (knowledge of hydatid infestation) and presentation are essential to achieve the correct diagnosis. When hydatid embolism is suspected, radiologists should search for the source of the emboli (hepatic cysts in communication with hepatic veins/vena cava, ruptured cyst in the right cardiac chambers).
MRI can be useful in the differential diagnosis, demonstrating the high signal in the T2-weighted sequences typical of cysts.
Pulmonary artery sarcoma is characterized by low-attenuating filling defect which can extend into lung parenchyma or mediastinum and shows diffuse enhancement.
Cases of hydatid pulmonary embolism are classified into three groups accordig to clinical course: acute fatal cases, subacute pulmonary hypertension cases resulting in death within 1 year and chronic pulmonary hypertension cases [2, 5, 7]. Our patient did not present with severe acute symptoms, neither did he develop chronic pulmonary hypertension. The patient is being regularly followed with echocardiography and shows no signs of increasing right ventricle pressure.
To confirm our diagnosis, the patient underwent VATS biopsy: a diagnosis of gigantocellular fibrogranulomatous nodules with ischemic necrosis and exogenous material referable to fragments of parasites was made.
Treatment of choice for hydatid pulmonary embolism is surgery. Given the anesthesiologic risk due to the permanent atrial fibrillation and the surgical risk of rupture of the artery or of the cyst with anaphylactic shock, we decided on repeated cycles of albendanzole and follow-up, in agreement with the patient.
After 2 years the patient reports a substantial stability in his symptomatology. The last follow up CT (Fig 3a-b) showed an increased extent of pulmonary arterial tree involvement; albendanzole therapy was then again started.
Differential Diagnosis List
Echinococcal pulmonary circulation embolism
Pulmonary thromboembolism
Pulmonary artery Sarcoma
Septic embolism
Tumor embolism
Final Diagnosis
Echinococcal pulmonary circulation embolism
References
[1] D. P. McManus, W.Zhang, J. Li, P. B. Bartley (2003) Echinococcosis. THE LANCET Vol 362
[2] A.G. Bach et al. (2013) Imaging of nonthrombotic pulmonary embolism: biological materials, nonbiological materials and foreign bodies. Eur J Radiol Mar; 82(3). (PMID: 23102488)
[3] A.H. Karantanas, G. Bitsios, E. Karaiskou. (2000) Echinococcus of the pulmonary artery: CT, MRI and MRA findings. Computerized Medical Imaging and Graphics 24 (2000) 265–267 (PMID: 10842051)
[4] J. B. Dixon (1997) Echinococcosis. Comp. Immun. Microbiol. infect. Dis Vol. 20, No. 1, pp. 87-94
[5] Han D, Lee KS, Franquet T, Müller NL, Kim TS, Kim H, Kwon OJ, Byun HS (2003) Thrombotic and nonthrombotic pulmonary arterial embolism: spectrum of imaging findings. Radiographics Nov-Dec;23(6):1521-39 (PMID: 14615562)
[6] Y. Namn, P.D. Maldian (2013) Hydatid cyst embolization to the pulmonary artery: CT and MR features. Emerg Radiol Dec;20(6):565-8. (PMID: 23686588)
[7] M.F. Damiani, Carratù P., Tatò I., Vizzino H., Florio C., Resta O (2012) Recurrent pulmonary embolism tue to echinococcosis secondary to hepatic surgery for hidatid cysts. J Comput Assist Tomogr Sep-Opt;36(5):534-5. (PMID: 22992602)
Case information
| URL: | https://www.eurorad.org/case/13162 |
| DOI: | 10.1594/EURORAD/CASE.13162 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
CT
These images demonstrate hypodense filling defects in the right middle lobe artery and in a segmental artery of left inferior lobe, compatible with embolism.
These images demonstrate hypodense filling defects in right middle lobe artery and in a segmental artery of left inferior lobe, compatible with embolism.
There are multiple bilateral tubular polilobulated opacities extending from the hylum to the peripheral zones of both lungs. The opacities have variable diameter (maximum 15 mm) and seem to be in continuity with pulmonary arteries.
A large multiloculated partly calcified echinococcal cyst is seen in III-IV hepatic segment; the lesion is in continuity with the left hepatic vein, which is not detectable, being filled with hypodense material.
A large multiloculated partly calcified echinococcal cyst is seen in III-IV hepatic segment; the lesion is continuity with left hepatic vein, which is not detectable, being filled with hypodense material.
Chest X-ray
Chest X-ray shows multiple bilateral nodular opacities (arrows) associated with parenchymal bands
Radiology Department, Maria Vittoria Hospital, Torino, Italia
Radiology Department, Maria Vittoria Hospital, Torino, Italia
CT
These images demonstrate hypodense filling defects in the right middle lobe artery and in a segmental artery of left inferior lobe, compatible with embolism.
Maria Vittoria Hospital, Torino, Italy
Maria Vittoria Hospital, Torino, Italy
These images demonstrate hypodense filling defects in right middle lobe artery and in a segmental artery of left inferior lobe, compatible with embolism.
Maria Vittoria Hospital, Torino, Italy
Maria Vittoria Hospital, Torino, Italy
There are multiple bilateral tubular polilobulated opacities extending from the hylum to the peripheral zones of both lungs. The opacities have variable diameter (maximum 15 mm) and seem to be in continuity with pulmonary arteries.
Maria Vittoria Hospital, Torino, Italy
Maria Vittoria Hospital, Torino, Italy
A large multiloculated partly calcified echinococcal cyst is seen in III-IV hepatic segment; the lesion is in continuity with the left hepatic vein, which is not detectable, being filled with hypodense material.
Maria Vittoria Hospital, Torino, Italia
Maria Vittoria Hospital, Torino, Italia
A large multiloculated partly calcified echinococcal cyst is seen in III-IV hepatic segment; the lesion is continuity with left hepatic vein, which is not detectable, being filled with hypodense material.
Maria Vittoria Hospital, Torino, Italia
Maria Vittoria Hospital, Torino, Italia
