as lymphoma and kaposi’s sarcoma, can also cavitate, especially in people with aids. lung cancers that develop cavities are associated with a poor prognosis (worse outcomes). cancers that metastasize (spread) to the lung can also develop cavitations, but this is only seen about 4% of the time on x-ray. metastatic cancers of squamous cell origin are also more likely to cavitate than cancers of other origins. both chemotherapy (drugs to treat cancer) and radiofrequency ablation (destroying cancer with radio waves) can cause lung cancers to develop cavities, which is a sign of a good response to treatment. it is possible to have both an infection and lung cancer in the same cavity; the most common combination is primary lung cancer and tuberculosis. autoimmune autoimmune causes of lung cavities include granulomatosis with polyangiitis, rheumatoid arthritis, and rarely necrotizing sarcoidosis (less than 1% of people with sarcoidosis develop lung cavities). ankylosing spondylitis, eosinophilic granulomatosis with polyangiitis, and systemic lupus erythematous rarely cause lung cavities. pulmonary embolism and septic emboli pulmonary embolism (a blood clot in the lung) causes pulmonary infarction (the death of lung tissue) less than 15% of the time, and only about 5% of pulmonary infarctions result in lung cavities. septic pulmonary emboli (infected blood clots) are collections of infectious organisms, fibrin, and platelets that travel through the blood to the lung and cause small areas of pulmonary infarction by blocking off blood flow. this results in multiple small cavities 85% of the time. symptoms can include cough, dyspnea (shortness of breath), chest pain, hemoptysis (coughing up blood) and sinus tachycardia (a fast heart rate). risk factors for septic pulmonary emboli include iv drug use, implanted prosthetic devices (like central lines, pacemakers, and right-sided heart valves), and septic thrombophlebitis (a blood clot in a vein due to infection). two forms of septic thrombophlebitis include pelvic thrombophlebitis and lemierre's syndrome (septic thrombophlebitis of the internal jugular vein). trauma pulmonary contusion (lung bruise) from blunt chest trauma causes bleeding into the alveoli (air sacs) and can cause small cavities to form that are called traumatic pulmonary pseudocysts (tpp). this is rare, as less than 3% of lung injuries lead to tpp. it can occur at any age, but is more common in children and adults under the age of 30. although it can occur anywhere in the lung, it is most common in the lower lobes. tpp usually resolves on its own within four weeks. congenital congenital lung cavities, or lung cavities present at birth, include bronchogenic cysts, congenital pulmonary airway malformation, and pulmonary sequestration. these congenital lesions are the most common cause of lung cavities in infants, children, and young adults. bronchogenic cysts are due to abnormal budding of the bronchial tree. about 70% are found in the mediastinum, which is the central part of the chest where the heart is. another 15 to 20% are intrapulmonary (within the lung), usually in the lower lobes. congenital pulmonary airway malformation, formerly called congenital cystic adenomatoid malformation, is a benign tumor the results in the formation of single or multiple cysts. pulmonary sequestration refers to abnormal lung tissue that gets its blood supply from the systemic circulation instead of the pulmonary circulation, like the rest of the lung. this lung tissue is also not connected to the trachea.