Pleuropulmonary Blastoma

Excerpt

Childhood tumors of the lung are rare malignant tumors accounting for 0.5% to 1% of all primary malignant lung tumors. These tumors are subdivided into 3 subtypes: pulmonary blastoma, fetal adenocarcinoma, and pleuropulmonary blastoma (PPB). An epithelial malignant and immature component characterizes fetal adenocarcinoma. A malignant immature mesenchymal proliferation characterizes the pleuropulmonary blastoma. Biphasic components define the blastoma; a mesenchymal and an epithelial malignant and immature component, that look like a 10- to 16-week gestational lung. In the 2015 World Health Organization Classification, fetal adenocarcinoma belongs to the group of adenocarcinomas, pulmonary blastoma belongs to the group of sarcomatoid carcinoma, and pleuropulmonary blastoma belongs to the group of mesenchymal tumors. Pleuropulmonary blastomas are rare tumors which present non-specific symptoms. Although the importance of the radiologic features to suspect the diagnosis, the positive diagnosis remains based on the microscopic features. Many synonyms of pleuropulmonary tumors exist in the literature including:

1. Cystic mesenchymal hamartoma

2. Mesenchymal cystic hamartoma

3. Pediatric pulmonary blastoma

4. Pneumoblastoma

5. Pulmonary rhabdomyosarcoma

6. Rhabdomyosarcoma in lung cyst