42. Lymphangitis carcinomatosa

Organ: Lung

Description:

On the surface of the visceral pleura can some greyish lines be seen. These lines have a web-like appearance.

Diagnosis: Lymphangitis carcinomatosa

Most common causes:

1. Primary lung carcinoma
2. Metastasis from breast carcinoma into the lung parenchyme

Theory:

Lymphangitis carcinomatosa is a sterile (no pathogens involved) inflammation of the lymphatic vessels because the lymphatic vessel lumen is occluded by tumor cells inside. The infiltration of tumor cells into the vessels cause them to become cord-like, especially in the area above the carcinoma.

It’s important to note that lymphangitis carcinomatosa isn’t inside the lung parenchyme but inside the visceral pleura. The tumor itself is, of course, in the parenchyme.

Lymphangitis carcinomatosa can be seen anywhere in the body but most commonly happens in the lungs, where the origin of the tumor cells are most frequently a primary lung carcinoma or a metastasis from a breast carcinoma.

Note that lymphangitis can only be seen on the left on the picture. The similar-looking structure on the right is just the normal bronchial tree.