A micro nodule
is a very small lump (less than 7 mm in diameter) located in an area of the lungs. A nodule is an anomaly detected on an imaging test such as a chest X-ray
or CT scan and having the appearance of a small rounded mass. It is called a nodule when the size is between 7 and 30 mm and a lung mass when it measures in excess of 1 inch. A pulmonary micro nodule is usually not visible on x-rays unless the nodule is calcified. It may appear due to benign causes such as certain infections, and won't be dangerous for health and disappear on its own at the same time as the resolution of the disease
. But a pulmonary micro nodule may also be indicative of a more severe disease, such as tuberculosis
, in some cases, even if the risk of cancer is very low when the nodule is less than 1 cm in size. It is then necessary to make an analysis after sampling, often performed by endoscopy, an examination requiring the introduction of a tube through the mouth
to the nodule.