What is apicopleural thickening as an impression in a lung x-ray?

Apicopleural thickening refers to the abnormal presence of excess tissue or fluid in the area where the apex of the lung meets the pleura, the lining of the chest cavity. It can be seen as a hazy, opaque, or dense region on a lung X-ray.

Causes of Apicopleural Thickening:

- Tuberculosis (TB): Apicopleural thickening is commonly associated with active or past tuberculosis infection. TB can cause inflammation and scarring in the lung apices, leading to thickening of the pleura.

- Fungal Infections: Certain fungal infections, such as histoplasmosis, coccidioidomycosis, and cryptococcosis, can also result in apicopleural thickening.

- Sarcoidosis: Sarcoidosis, a systemic inflammatory disease, can affect the lungs and cause apicopleural thickening.

- Post-Radiation Changes: Radiation therapy to the chest can lead to fibrosis and thickening of the pleura, resulting in apicopleural thickening.

- Asbestosis: Inhalation of asbestos fibers can cause scarring and thickening of the pleura, including the apices.

- Other Infections: Infections like pneumonia, especially organizing pneumonia, can cause temporary apicopleural thickening.

- Rheumatic Diseases: Some rheumatic conditions, such as rheumatoid arthritis, can cause inflammatory changes in the pleura, leading to thickening.

- Neoplasms: Rarely, apicopleural thickening can be associated with certain lung tumors or malignancies.

Importance:

Apicopleural thickening can be an important observation on a chest X-ray. While it may suggest certain underlying causes, further evaluation is necessary to determine the specific etiology. Additional imaging studies, laboratory tests, and medical history correlation are often required to confirm the diagnosis and rule out serious conditions.