Pleuropulmonary blastoma (PPB) is a rare cancer originating in the lung or pleural cavity. It occurs most often in infants and young children but also has been reported in adults. In a retrospective review of 204 children with lung tumors, pleuropulmonary blastoma and carcinoid tumor were the most common primary tumors (83% of the 204 children had secondary tumors spread from cancers elsewhere in the body). Pleuropulmonary blastoma is regarded as malignant. The male:female ratio is approximately one. Signs and symptoms
Symptoms may include coughing, an upper respiratory tract infection, shortness of breath, and chest pain. These symptoms are very non-specific, and can be caused by other types of tumor in the lung or mediastinum more generally, and by other conditions. Imaging (X-ray, CT, MRI) may be used to determine the presence and precise location of a tumor, but not a specific diagnosis of PPB or other tumor. Doctors are unable to tell if a child has PPB right away, and not upper respiratory tract infection, until more test are taken and they show that there is no infection. Another symptom is pneumothorax. Genetics
A number of PPBs have shown trisomy 8 (17 out of 23 cases studied per the PPB registry). Trisomy 2 and p53 mutations/deletions have also been described.An association with mutations in the DICER1 gene has been reported. Mutations in this gene are found in 2/3 cases. Diagnosis
The most common way to test someone for PPB is to take a biopsy.
Non-pigmented AKs: linear or wavy vascular patterning, or a "strawberry pattern," described as unfocused vessels between hair follicles, with white-haloed follicular openings. Pigmented AKs: gray to brown dots or globules surrounding follicular openings, and annular-granular rhomboidal structures; often difficult to differentiate from lentigo maligna. Prevention
Ultraviolet radiation is believed to contribute to the development of actinic keratoses by inducing mutations in epidermal keratinocytes, leading to proliferation of atypical cells. Therefore, preventive measures for AKs are targeted at limiting exposure to solar radiation, including:

Limiting extent of sun exposure
Avoid sun exposure during noontime hours between 10:00 AM and 2:00 PM when UV light is most powerful
Minimize all time in the sun, since UV exposure occurs even in the winter and on cloudy days
Using sun protection
Applying sunscreens with SPF ratings 30 or greater that also block both UVA and UVB light, at least every 2 hours and after swimming or sweating
Applying sunscreen at least 15 minutes before going outside, as this allows time for the sunscreen to be absorbed appropriately by the skin
Wearing sun protective clothing such as hats, sunglasses, long-sleeved shirts, long skirts, or trousersRecent research implicating human papillomavirus (HPV) in the development of AKs suggests that HPV prevention might in turn help prevent development of AKs, as UV-induced mutations and oncogenic transformation are likely facilitated in cases of active HPV infection.