A solitary pulmonary nodule ( SPN ) or coin lesion is a mass in the lung that is less than 3 cm in diameter. This could be an incidental finding found in 0.2% chest x-ray and about 1% CT scan.
Nodules most often are benign tumors such as granuloma or hamartoma, but in about 20% of cases it is a malignant cancer, especially in older adults and smokers. In contrast, 10 to 20% of patients with lung cancer are diagnosed in this way. If the patient has a history of smoking or nodules growing the chances of cancer may need to be excluded through further radiological studies and interventions, possibly including surgical resection. The prognosis depends on the underlying conditions.
Video Solitary pulmonary nodule
Definisi
Nocular density is used to distinguish larger lung tumors, smaller infiltrates or masses with other accompanying characteristics. The most commonly used formal radiological definitions are as follows: a single lesion in the lung that is completely surrounded by the lung parenchyma (functional tissue) with a diameter of less than 3 cm and without associated pneumonia, atelectasis (lung collapse) or lymphadenopathy (swollen lymph nodes).
Maps Solitary pulmonary nodule
Cause
Not every round point on a radiological image is a solitary pulmonary nodule: it should not be confused with the projection of the chest or skin wall structures, such as nipples, rib fractures or monitoring of healing electrocardiography.
The most important causes to exclude are the forms of lung cancer, including rare forms such as primary lung lymphoma, carcinoid tumors and solitary metastases to the lungs (the location of unrecognized primary tumors is melanoma, sarcoma or testicular cancer). Benign tumors in the lungs include hamartomas and chondromas.
The most common benign coin lesions are granulomas (inflammatory nodules), for example due to tuberculosis or fungal infections, such as Coccidioidomycosis. Other infectious causes include pulmonary abscesses, pneumonia (including pneumocystis carinii pneumonia) or nocardial infections or rare infections of worms (such as difilariasis or heartworm dog infestations). Pulmonary nodules can also occur in immune disorders, such as rheumatoid arthritis or granulomatosis with polyangiitis, or organizing pneumonia.
NES can be found as an arteriovenous malformation, hematoma or infarct zone. This may also be caused by bronchial atresia, sequestration, inhaled foreign bodies or pleural plaques.
Diagnosis
Diagnosis can be made with lung biopsy. A small biopsy obtained with a core needle or bronchoscopy is usually used for the diagnosis of pulmonary nodules. CT guided percutaneous transthoracic needle biopsy also proved helpful in NND diagnosis. Some features help differentiate benign conditions from the likelihood of lung cancer. The first parameter is the size of the lesion: the smaller, the less the risk of malignant cancer. The benign causes tend to have well-defined limits, whereas lesions are lobulated or those with irregular margins extending into neighboring tissues tend to be malignant.
The growth of nodules also helps determine their status (malignant, infectious, or benign) in the body based on the time it takes for the volume to be doubled. Typical values ​​are less than 20 days, less than 100 days, or more than 400 days for nodules based on infection, malignancy, and benign benign.
If there is a central cavity, thin walls point to a benign cause whereas thick walls are associated with malignancy (especially 4 mm or less compared to 16 mm or more). In lung cancer, cavitation may represent central tumor necrosis (tissue death) or secondary abscess formation. If the airway wall is visible (air bronchogram), bronchioloalveolar carcinoma is a possibility.
SPN often contains calcifications. Certain calcification patterns are convincing, like the appearance of a popcorn-like hamartoma. SPNs with densities below 15 Hounsfield units on computed tomography tend to be benign, whereas malignant tumors often measure more than 20 Hounsfield units. The fatty tissue inside the hamartomas will have a very negative value on the Hounsfield scale.
The rate of growth of lesions is also informative: tumors that grow very quickly or very slow are rarely malignant, as opposed to inflammatory or congenital conditions. It is therefore important to take a prior imaging study to see if the lesion is presented and how quickly the volume increases. This is more difficult for nodules smaller than 1 centimeter. In addition, the predictive value of stable lesions over a 2-year period has been found to be somewhat low and unreliable.
Prevention and filtering
Medical history, physical examination and imaging results form the basis of the initial risk assessment and determine the next course of action. Most patients will undergo CT scans.
Some patient factors may affect the likelihood of benign versus malignant conditions: this includes previous exposure to smoke or other carcinogens such as asbestos and previously diagnosed cancers, respiratory infections, or chronic obstructive pulmonary disease. A patient with airway symptoms, especially coughing up blood (hemoptysis), is more likely to have cancer than patients without respiratory symptoms.
Treatment
When solitary pulmonary nodules are identified, plans for further action are made based on the possibility that the nodule may become malignant. If the risk of malignancy is considered low, imaging follow-up (usually serial CT scan) may be planned later. If the initial impression is that there is a high chance of cancer, then surgical intervention (such as thoracoscopic video-assisted surgery) is appropriate (provided the patient is fit for surgery). For cases where some action is required but the situation is uncertain, guidelines exist to recommend how much supervision should exist in the prescribed circumstances. If the pulmonary nodule has not grown for two years and the person has no previous cancer history then the nodule is highly unlikely to become malignant. If the nodule is "ground glass" then further follow-up is required but the same applies. CT scans more often than recommended have not been shown to improve yield but will increase radiation exposure and unnecessary health care can be expected to make patients anxious and uncertain.
If there is an intermediate risk of malignancy, further imaging with positron emission tomography (PET scan) is appropriate (if available). Approximately 95% of patients with malignant nodules will have abnormal PET scans, while about 78% of patients with benign nodules will look normal on PET (this is the sensitivity and specificity of the test). Thus, abnormal PET scanning would be reliable for taking cancer, but some other nodules (inflammatory or infectious, for example) would also appear on the PET scan. If the nodule has a diameter below 1 centimeter, PET scans are often avoided because there is an increased risk of incorrect outcomes. Cancer lesions usually have a high metabolism on PET, as indicated by high FDG (radioactive sugar) intake. If the lesion is found in further imaging to become suspicious, surgery must be performed (via thoracotomy or video-assisted thoracic surgery) to confirm the diagnosis by microscopic examination.
In some cases, nodules may also be sampled through the airways using bronchoscopy or through the chest wall using needle aspiration (which can be done with a CT guide). Needle aspiration can only take groups of cells to cytology and not tissue cylinders or biopsies, which hinder the evaluation of network architecture. Theoretically, this makes the diagnosis of a benign condition more difficult, although a higher rate of 90% has been reported. Complications of the latter technique include bleeding into the lungs and air leakage in the pleural space between the lungs and the chest wall (pneumothorax). However, not all cases of pneumothorax require treatment with a chest tube.
Other imaging techniques include PET-CT (simultaneous PET scanning and CT scan with image superposition), magnetic resonance imaging (MRI) or single photon emission tomography (SPECT).
Footnote
Source of the article : Wikipedia
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