Pleuropulmonary blastoma
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Faizan Sheraz, M.D. [2], Maria Fernanda Villarreal, M.D. [3]
Synonyms and keywords: Pulmonary blastoma; PPB
Overview
Pleuropulmonary blastoma (PPB) is a rare intrathoracic malignancy originating in the lung or pleural cavity. Pleuropulmonary blastoma occurs most often in infants and young children.[1] The pathogenesis of pleuropulmonary blastoma is characterized by resembling immature lung tissue. The p53 mutations/deletions have been associated with the development of pleuropulmonary blastoma. Pleuropulmonary blastoma may be classified into 3 groups: type I, II, III. Common causes of pleuropulmonary blastoma include trisomy 8, trisomy 2, and p53 mutations/deletions (e.g., Li-Fraumeni syndrome). On gross pathology, characteristic findings of pleuropulmonary blastoma include extra-pulmonary location, and attachment to the parietal pleura. Pleuropulmonary blastoma is more commonly observed among patients between 0-2 years old. Complete surgical resection is often most common approach to the treatment of pleuropulmonary blastoma.[2]
Historical Perspective
- Pleuropulmonary blastoma was first discovered by Dr. Juan C. Manivel, MD in 1988.[3]
Classification
- Pleuropulmonary blastoma may be classified into 3 groups:[2]
- Type I: multicystic lesions
- Type II: thickened areas (nodules) within cystic lesions
- Type III: solid masses
- Type I PPB is made up of mostly cysts, and may be hard to distinguish from benign lung cysts; not all type I PPB will progress to types II and III.
Pathophysiology
- The pathogenesis of pleuropulmonary blastoma is characterized by resembling immature lung tissue.[2]
- The p53 and DICER-1 gene mutations/deletions have been associated with the development of pleuropulmonary blastoma.[2]
- On gross pathology, characteristic findings of pleuropulmonary blastoma include:[4]
- Extrapumonary mass
- Attachment to the parietal pleura
- On microscopic histopathological analysis, characteristic findings of pleuropulmonary blastoma include:
- Epithelial component
- Mesenchymal component
- Small, round cells
- On inmunohistochemistry analysis, characteristic findings of pleuropulmonary blastoma include:[2]
Causes
- Common causes of pleuropulmonary blastoma include:[2]
- Trisomy 8
- Trisomy 2
- p53 mutations/deletions
Differentiating Pleuropulmonary Blastoma from Other Diseases
- Pleuropulmonary blastoma must be differentiated from other diseases that cause cough or recurrent upper respiratory tract infections, such as:[4]
- Intrathoracic soft tissue sarcoma
- Large bronchogenic cyst or lung cyst (for type I)
- Fetal lung interstitial tumor
Epidemiology and Demographics
- Pleuropulmonary blastoma is very uncommon.[2]
Age
- Pleuropulmonary blastoma is more commonly observed among patients between 0-2 years old.
- Pleuropulmonary blastoma is more commonly observed among infants and children.
- Pleuropulmonary blastoma is less commonly observed among adults.[4]
Gender
- Pleuropulmonary blastoma affects men and women equally.
Race
- There is no racial predilection for pleuropulmonary blastoma
Risk Factors
- There are no risk factors associated with the development of pleuropulmonary blastoma.[2]
Natural History, Complications and Prognosis
- The majority of patients with pleuropulmonary blastoma are asymptomatic.
- Pleuropulmonary blastoma is usually an incidental finding during routine examination.[4]
- Early clinical features include persisting upper respiratory tract infection, coughing, and shortness of breath.
- If left untreated, the majority of patients with may progress to develop acute respiratory distress syndrome.
- Common complications of pleuropulmonary blastoma include respiratory failure, pneumonia, or mortality.
- Prognosis is generally poor, and the 5-year survival rate of patients with pleuropulmonary blastoma is approximately 15%.
- Pleuropulmonary blastomas larger than 5 cm have a worse prognosis.
Diagnosis
Symptoms
- Pleuropulmonary blastoma is usually asymptomatic.
- Symptoms of pleuropulmonary blastoma are often non-specific.
- Symptoms of pleuropulmonary blastoma may include the following:[4]
Physical Examination
- Patients with pleuropulmonary blastoma usually have dysmorphic facies.[4]
- Physical examination may be remarkable for:
- Eye anomalies
- Mental retardation
- Skin hypopigmentation
- Congenital skeletal abnormalities
- Short stature
- Premature aging
Laboratory Findings
- There are no specific laboratory findings associated with pleuropulmonary blastoma.
Imaging Findings
- CT is the imaging modality of choice for pleuropulmonary blastoma. On CT, findings of pleuropulmonary blastoma may include:
- Large mass in the thorax with solid mixed cystic heterogeneous low attenuation
- Pleural effusion
- Contralateral mediastinal shift
- Lack of chest wall invasion
- On conventional radiograph, findings of pleuropulmonary blastoma may include pseudo-cardiomegaly.[4]
Treatment
Medical Therapy
- There is no treatment for pleuropulmonary blastoma; the mainstay of therapy is supportive care.[4]
Surgery
- Surgery is the mainstay of therapy for pleuropulmonary blastoma.
- Complete surgical resection is often most common approach to the treatment of pleuropulmonary blastoma.
Prevention
- There are no primary preventive measures available for pleuropulmonary blastoma.[4]
References
- ↑ Indolfi P, Casale F, Carli M, et al. (September 2000). "Pleuropulmonary blastoma: management and prognosis of 11 cases". Cancer. 89 (6): 1396–401. doi:10.1002/1097-0142(20000915)89:6<1396::AID-CNCR25>3.0.CO;2-2. PMID 11002236.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Radiopedia. Dr. Henry Knipe. http://radiopaedia.org/articles/pleuropulmonary-blastoma Accessed on April 20, 2016
- ↑ Manivel JC, Priest JR, Watterson J, Steiner M, Woods WG, Wick MR; et al. (1988). "Pleuropulmonary blastoma. The so-called pulmonary blastoma of childhood". Cancer. 62 (8): 1516–26. PMID 3048630.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Dehner LP (1994). "Pleuropulmonary blastoma is THE pulmonary blastoma of childhood". Semin Diagn Pathol. 11 (2): 144–51. PMID 7809508.