Pleuropulmonary blastoma

Abstract

Pleuropulmonary blastoma (PPB) is a rare and aggressive malignant tumor that affects children and adults. This neoplasm is histologically characterized by primitive blastema and a malignant mesenchymal stroma that often demonstrates multidirectional differentiation. Despite the introduction of multimodal therapy, the prognosis of patients with PPB remains poor. In the current study the authors reported on PPB cases from a national retrospective search performed in 18 Italian Associations for Pediatric Hematology and Oncology centers. Clinical data, surgical notes, pathologic findings, and summaries of chemotherapy and radiotherapy were obtained from reports and correlated with outcome by standard statistical methods. The series included 11 patients (7 boys and 4 girls) with a median age of 32 months. Respiratory distress was the most common clinical symptom. In three patients the PPB developed from other primary dysplastic diseases: cystic adenomatoid malformation in one case and congenital lung cysts in the other two cases. Five patients experienced disease recurrences (local recurrence in three patients and distant metastasis in two patients, within the central nervous system and an intraocular location, respectively). Patients with a type 2 histologic pattern and/or pleural involvement were found to have a worse outcome compared with patients without such features. Event free survival at 2 years from the time of diagnosis was 45% for all patients. Overall survival at 2 years was 72% for all patients. PPB is an aggressive neoplasm of early childhood and to the authors' knowledge no adequate therapy has been defined to date for patients with PPB. After making the diagnosis, the main goal of therapy should be radical surgery, even in patients with microscopic residual disease. Because the response to chemotherapy is poor, the authors' experience suggests that chemotherapy should be given with local radiotherapy in the majority of patients.