PPB is a kind of cancer. What is cancer? Cells are the essential building blocks of all organs in the body. Cells must behave in highly organized ways in order for organs to develop and function. Cancer occurs when cells cease to be precisely behaved and well organized. They stop “following the rules” and essentially go wild. Cancerous (malignant) cells grow uncontrollably, forming tumors. Cancerous cells can cross borders and invade nearby tissue, and they may break loose and spread around the body. What causes cells to become malignant is generally not known. In adults, cancer can be associated with long-term exposure to such things as tobacco or sunlight. In children, lengthy exposures do not occur, and the causes for cancer are generally unknown.
PPB is an extremely rare disease, and thus much less is known about it than is known about the more common childhood cancers such as leukemia. This makes it much more difficult for physicians to select curative therapies.
Pleuropulmonary blastoma (PPB) is a kind of “lung cancer”. The name “pleuropulmonary blastoma” is complex medical language. It means that the disease is thought to originate in either the tissue covering the lungs and inside surface of the chest cavity (“pleura”) or in the lung tissue itself (“pulmonary”). The word “blastoma” has to do with the appearance of the cancer under the microscope, and it suggests a “primitive”, almost embryo-like, appearance. The name itself is not important; however the accurate identification of any cancer is extremely important. PPB occurs almost exclusively in children. A disease known as “pulmonary blastoma” occurs in adults; it is also rare and, despite the similarity of the names, it is very different from PPB.
PPB is almost the only form of cancer that originates in the lung tissue of children. Thus, PPB is a kind of “lung cancer”, but it is very different from the kind of lung cancer that occurs in adults. In children, cancers of other organs may spread to lung tissue, but these are not truly lung cancers. A number of pediatric cancers involve the lymph-node tissue in the center of the chest, but these are also not cancers of the lung. “Lung cancer” of the type that occurs in adults is almost never diagnosed in children.
PPB occurs in children from the newborn period through 12 years of age (with rare patients in the mid-teens, a few 18 - 23 year olds, and one 36-year-old reported). The average age of children with PPB is 3 - 4 years. It is so rare that it is not likely to be considered by any physician when a child first has symptoms. It is so rare that many physicians will never have heard of it, and rarely will a physician have had any experience with it.. Cough, fever and sometimes pain in the chest suggesting a respiratory infection are often the first symptoms. Even chest x-rays may first be interpreted as “pneumonia”. The diagnosis may not be made until a child fails to improve after treatment for what is thought to be an infection, and further investigation is done. Air in the chest cavity, known as pneumothorax, is another common way for PPB to make itself known. There are other reasons for pneumothorax, so again PPB may temporarily elude diagnosis.