Symptoms

The initial symptoms of lung cancer, if they occur at all, are very unspecific. Although coughing with or without sputum is a sign of lung disease, it is not primarily thought of as a lung tumor. However, if the symptoms persist over a longer period of time, if serious infections such as pneumonia occur or if blood is coughed up repeatedly, a malignant disease must be ruled out.

The growth in size of an existing bronchial carcinoma can lead to pressure and occlusion of various organs. The bloodstream may be obstructed, swallowing difficulties may occur and respiratory distress may occur under stress. If the tumor infiltrates muscle or bone tissue, this is not only a sign of its advanced stage, but is also associated with considerable pain. The symptoms of a so-called paraneoplastic syndrome, which is more common in small cell bronchial carcinomas, can be very diverse. Due to the hormone-like substances that the tumor releases, excessive production of other hormones, inflammation, fluctuations in the electrolyte balance, thrombosis and psychiatric disorders with extensive clinical pictures can occur.

How can lung cancer be detected in an X-ray image?

On X-rays, tumors in the lungs above a certain size can be recognized by certain features. Tumors smaller than 1 cm are often overlooked, making early detection and a promising therapy difficult. The tumor tissue has a higher density than the lung tissue.

The latter consists of air-filled pulmonary alveoli and appears dark in the X-ray. This means that few X-rays are absorbed, which makes sense considering the low density of the tissue. The tumor tissue consists of a large number of densely packed cells.

Consequently, the tissue absorbs many X-rays and the tumor appears brighter in the image than the surrounding tissue.Only X-rays that have passed through the body are recorded in the X-ray image as the smallest dark point. The interplay of the points results in the final image. Tumors usually grow in a round shape like a herd.

If other brightened spots are visible in the lung with its otherwise regular structure in addition to the large bronchial tubes, the examining physician should be alert. Malignant masses do not adhere to the anatomical limits of the lung. They can cross the supply areas of the individual bronchi and even the individual lobes of the lungs.

Some advanced lung tumors even grow beyond the organ boundaries and penetrate bone and muscle tissue or the pleura (costal pleura). The form of benign and malignant tumors differs significantly. While benign tumors have smooth edges, lung cancer grows infiltrating, i.e. penetrating.

The cancer cells grow radiating from a center into the surrounding tissue. This means that the tissue is not displaced, as is the case with benign tumors or cysts, but infiltrated. In the case of degenerated cell tissue, calcium deposits often occur.

This can be seen in the X-ray image as radiopaque granules (white). So-called microcalcification is a classic sign of a benign tumor, but does not yet give the all-clear – even though calcifications are very rare in lung cancer, they are still possible. However, since calcification is clearly visible in the X-ray image, it gives an indication of an existing change in the tissue. Now a biopsy can be performed to remove the tissue and then examine it in the laboratory. X-ray diagnostics is the mainstay in the detection of lung cancer and is often supported by CTs in the further course of the disease, as this is the only way to determine the exact boundaries of the tumor.