Pleuropulmonary blastoma

Pleuropulmonary blastoma, often abbreviated PPB, is a rare cancer that begins in the lung or in the pleural cavity around it. It occurs most often in infants and young children, although cases in adults have been reported, and it is regarded as malignant. Early signs such as cough, shortness of breath, chest pain or an apparent upper respiratory infection are non-specific, and imaging can show a tumour but cannot confirm the diagnosis, which needs a biopsy. The tumour is classed into three types, from a mostly cystic form (type I) through a mixed cystic and nodular form (type II) to a solid mass (type III), and types II and III are aggressive. Mutations in the DICER1 gene are found in about two thirds of cases. Surgery is the main treatment, sometimes after chemotherapy, and screening continues for several years because the tumour can return. It was first described in 1988 and an international registry exists.