Pleuropulmonary blastoma
Updates to Article Attributes
Pleuropulmonary blastomas (PPB) are rare, variably aggressive, childhood primary intrathoracic malignancy. In up to 25% of cases, the mass can be extrapulmonary with attachment to the parietal pleura 2.
Epidemiology
It is encountered in childhood, mostly in the first years of life (90% in those between 0 - 2-2 years old).
Pathology
It comprises of mesenchymal and epithelial components resembling fetal lung.
Classification
-
cystic:
:type I-(prenatal and 10 months old)-, 14% -
mixed:
:type II-(mean age 34 months)-, 48% -
solid:
:type III-(mean age 44 months)-, 38%
This classification is a continuum from the less malignant to the most malignant lesion. Type 1 PPB's are impossible to differentiate from types 1 and 4 CPAM. Thus, it must be included in the differential diagnosis, particularly if the patient is known for another type of blastoma, as 25% of PPB appear in families with history of blastomas. PPBs are usually right sided, pleural bases, without chest wall invasion and without calcifications. It can sometime present with pneumothorax. Types 2 and 3 PPBs are associated with CNS and bone metastases.
Associations
There is some reported association with the presence of intrapulmonary cysts.
Pleuropulmonary blastomas is associated with PPB family tumour and dysplasia syndrome in 33% of cases. Many of these patients have a mutation of the DICER-1 gene. In 10% of cases, patient with PPB may also present with multilocular cystic nephroma, and, very rarely, Wilms tumour 7-9.
Radiographic features
Often late presentation at radiographic diagnosis. Unilateral lung whiteout on plain film with mediastinal shift to opposite side. Usually there is no adjacent rib erosions or calcification.
CT
Usually seen as a large mass in the thorax with solid mixed cystic heterogeneous low attenuation, pleural effusion (not dominant abnomality), contralateral mediastinal shift, and lack of chest wall invasion 3-4.
Treatment and prognosis
Type I tumours have a good prognosis. Complete surgical resection is often the treatment of choice, as it is with CPAM. Tumors larger than 5 cm just like type 1 and 2 PPB carry a worse prognosis 2.
Differential diagnosis
General imaging differential considerations include:
- intrathoracic soft tissue sarcoma
- PNET of thorax
- large bronchogenic cyst
/ lung/lung cyst (for type I) - FLIT (fetal lung interstitial tumour)10
- types 1 and 4 CPAM's
-: for type 1 PPB
See also
-<p><strong>Pleuropulmonary blastomas (PPB)</strong> are rare, variably aggressive, childhood primary intrathoracic malignancy. In up to 25% of cases, the mass can be extrapulmonary with attachment to the <a href="/articles/parietal-pleura" title="parietal pleura">parietal pleura</a> <sup>2</sup>. </p>-<div>-<h4>Epidemiology</h4>-<p>It is encountered in childhood, mostly in the first years of life (90 % in those between 0 - 2 years old).</p>-</div>-<h4><strong>Pathology</strong></h4>-<p>It comprises of mesenchymal and epithelial components resembling fetal lung.</p>-<h5>Classification</h5>-<ul>-<li>-<strong>cystic</strong> : type I - (prenatal and 10 months old) - 14 %</li>-<li>-<strong>mixed</strong> : type II - (mean age 34 months) - 48 %</li>-<li>-<strong>solid</strong> : type III - (mean age 44 months) - 38 %</li>-</ul><p>This classification is a continuum from the less malignant to the most malignant lesion. Type 1 PPB's are impossible to differentiate from types 1 and 4 <a title="CPAM" href="/articles/cpam">CPAM</a>. Thus, it must be included in the differential diagnosis, particularly if the patient is known for another type of blastoma, as 25 % of PPB appear in families with history of blastomas. PPBs are usually right sided, pleural bases, without chest wall invasion and without calcifications. It can sometime present with pneumothorax. Types 2 and 3 PPBs are associated with CNS and bone metastases.</p>-<h5>Associations</h5>-<p>There is some reported association with the presence of <a title="Pulmonary cysts" href="/articles/pulmonary-cyst">intrapulmonary cysts</a>. </p>-<p>Pleuropulmonary blastomas is associated with PPB family tumour and dysplasia syndrome in 33 % of cases. Many of these patients have a mutation of the DICER-1 gene. In 10 % of cases, patient with PPB may also present with multilocular cystic nephroma, and, very rarely, Wilms tumour <sup>7-9</sup>.</p>-<h4><strong>Radiographic features</strong></h4>-<p>Often late presentation at radiographic diagnosis. Unilateral lung whiteout on plain film with mediastinal shift to opposite side. Usually there is <strong>no</strong> adjacent rib erosions or calcification.</p>-<h5>CT</h5>-<p>Usually seen as a large mass in the thorax with solid mixed cystic heterogeneous low attenuation, pleural effusion (not dominant abnomality), contralateral mediastinal shift, and lack of chest wall invasion <sup>3-4</sup>.</p>-<h4>Treatment and prognosis</h4>-<p>Type I tumours have a good prognosis. Complete surgical resection is often the treatment of choice, as it is with <a title="CPAM" href="/articles/congenital-pulmonary-airway-malformation">CPAM</a>. Tumors larger than 5 cm just like type 1 and 2 PPB carry a worse prognosis <sup>2</sup><sub>.</sub></p><strong>-<h4>Differential diagnosis</h4></strong>-<p>General imaging differential considerations include:</p>-<ul>-<li><a title="intrathoracic soft tissue sarcoma" href="/articles/intrathoracic-soft-tissue-sarcoma">intrathoracic soft tissue sarcoma</a></li>-<li>-<a title="CNS primitive neuroectodermal tumour (PNET)" href="/articles/primitive-neuroectodermal-tumour-of-the-cns">PNET </a>of thorax</li>-<li>large <a title="bronchogenic cyst" href="/articles/bronchogenic-cyst">bronchogenic cyst</a> / lung cyst (for type I)</li>-<li>-<a href="/articles/flit" title="FLIT" style="color: rgb(63, 117, 216); text-decoration: none; ">FLIT</a> (fetal lung interstitial tumour)<sup>10</sup>-</li>-<li>types 1 and 4 <a title="CPAM" href="/articles/cpam">CPAM</a>'s - for type 1 PPB</li>-</ul><h4>See also</h4><ul><li><a href="/articles/primary-sarcomatoid-carcinoma-of-lung" title="Sarcomatoid carcinoma of the lungs">sarcomatoid carcinoma of the lungs</a></li></ul>- +<p><strong>Pleuropulmonary blastomas (PPB)</strong> are rare, variably aggressive, childhood primary intrathoracic malignancy. In up to 25% of cases, the mass can be extrapulmonary with attachment to the <a href="/articles/parietal-pleura">parietal pleura</a> <sup>2</sup>. </p><h4>Epidemiology</h4><p>It is encountered in childhood, mostly in the first years of life (90% in those between 0-2 years old).</p><h4><strong>Pathology</strong></h4><p>It comprises of mesenchymal and epithelial components resembling fetal lung.</p><h5>Classification</h5><ul>
- +<li>
- +<strong>cystic:</strong> type I (prenatal and 10 months old), 14%</li>
- +<li>
- +<strong>mixed:</strong> type II (mean age 34 months), 48%</li>
- +<li>
- +<strong>solid:</strong> type III (mean age 44 months), 38%</li>
- +</ul><p>This classification is a continuum from the less malignant to the most malignant lesion. Type 1 PPB's are impossible to differentiate from types 1 and 4 <a href="/articles/cpam">CPAM</a>. Thus, it must be included in the differential diagnosis, particularly if the patient is known for another type of blastoma, as 25% of PPB appear in families with history of blastomas. PPBs are usually right sided, pleural bases, without chest wall invasion and without calcifications. It can sometime present with pneumothorax. Types 2 and 3 PPBs are associated with CNS and bone metastases.</p><h5>Associations</h5><p>There is some reported association with the presence of <a href="/articles/pulmonary-cyst">intrapulmonary cysts</a>.</p><p>Pleuropulmonary blastomas is associated with PPB family tumour and dysplasia syndrome in 33% of cases. Many of these patients have a mutation of the DICER-1 gene. In 10% of cases, patient with PPB may also present with multilocular cystic nephroma, and, very rarely, Wilms tumour <sup>7-9</sup>.</p><h4><strong>Radiographic features</strong></h4><p>Often late presentation at radiographic diagnosis. Unilateral lung whiteout on plain film with mediastinal shift to opposite side. Usually there is <strong>no</strong> adjacent rib erosions or calcification.</p><h5>CT</h5><p>Usually seen as a large mass in the thorax with solid mixed cystic heterogeneous low attenuation, pleural effusion (not dominant abnomality), contralateral mediastinal shift, and lack of chest wall invasion <sup>3-4</sup>.</p><h4>Treatment and prognosis</h4><p>Type I tumours have a good prognosis. Complete surgical resection is often the treatment of choice, as it is with <a href="/articles/congenital-pulmonary-airway-malformation">CPAM</a>. Tumors larger than 5 cm just like type 1 and 2 PPB carry a worse prognosis <sup>2</sup><sub>.</sub></p><h4><strong>Differential diagnosis</strong></h4><p>General imaging differential considerations include:</p><ul>
- +<li><a href="/articles/intrathoracic-soft-tissue-sarcoma">intrathoracic soft tissue sarcoma</a></li>
- +<li>
- +<a href="/articles/primitive-neuroectodermal-tumour-of-the-cns">PNET </a>of thorax</li>
- +<li>large <a href="/articles/bronchogenic-cyst">bronchogenic cyst</a>/lung cyst (for type I)</li>
- +<li>
- +<a href="/articles/flit">FLIT</a> (fetal lung interstitial tumour)<sup>10</sup>
- +</li>
- +<li>types 1 and 4 <a href="/articles/cpam">CPAM</a>'s: for type 1 PPB</li>
- +</ul><h4>See also</h4><ul><li><a href="/articles/primary-sarcomatoid-carcinoma-of-lung">sarcomatoid carcinoma of the lungs</a></li></ul>
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