A review study in the July 2008 issue of “Archives of Pathology and Pulmonary Medicine” reports that lung tumors are rare in children and most often are noncancerous (see Reference 1). Of the rare primary tumors in children, this study reports that the most common are pleuropulmonary blastoma and carcinoid tumor (see Reference 1). Even more rare types of lung tumors in children include congenital peribronchial myofibroblastic tumor, sarcomas, carcinoma and mesothelioma.
Congenital defects, abnormalities that occur in a developing fetus, may have an underlying genetic cause or are a consequence of an abnormal intrauterine environment. Congenital lungs cysts sometimes develop in fetuses and can be detected early by ultrasound. An article in “Pediatric Pulmonology” says that pleuropulmonary blastoma, or PPB, is the most frequent malignant lung cancer associated with childhood lung cysts. This source also reports that surgical removal with or without chemotherapy cures between 85 and 90 percent of children with this disease (see Reference 2). PPB clusters in families and can be genetically determined in most cases. A recent study published in “Science” reports that familial PPB is associated with a mutation in the gene that encodes for the protein, DICER (see Reference 3).
Most tumors that develop in the lungs of children originate in another tissue first. Metastasis is the process when cancer cells from one tissue are released into the bloodstream and invade other remote tissues. The review study in the “Archives of Pathology and Pulmonary Medicine” says that most lung cancers in children are caused by tumors that have metastasized from other sites (see Reference 1). These types of lung cancers are called secondary, and the authors of this study found that Wilms tumor and osteosarcoma were most often the primary cancers that metastasized to the lung in pediatric patients.
AIDS-Associated Lung Cancers
AIDS is a disease in which the immune system is progressively compromised. The immune system continuously surveys the body for abnormal cells like those found in tumors. Children who have AIDS have less protection against the formation of tumors and are at risk for other types of lung cancer, such as Epstein-Barr virus–related smooth muscle tumors and lymphoma.