Mesothelioma

Today’s path rounds are on 𝐦𝐞𝐬𝐨𝐭𝐡𝐞𝐥𝐢𝐨𝐦𝐚!

𝐖𝐡𝐚𝐭 𝐢𝐬 𝐢𝐭?
𝐌𝐞𝐬𝐨𝐭𝐡𝐞𝐥𝐢𝐨𝐦𝐚 is a tumour that arises from the 𝐦𝐞𝐬𝐨𝐭𝐡𝐞𝐥𝐢𝐮𝐦, the lining of the body cavities. These linings include the 𝐩𝐥𝐞𝐮𝐫𝐚 (lining the thorax), the 𝐩𝐞𝐫𝐢𝐭𝐨𝐧𝐞𝐮𝐦 (lining the abdomen) and the 𝐩𝐞𝐫𝐢𝐜𝐚𝐫𝐝𝐢𝐮𝐦 (around the heart).

𝐖𝐡𝐨 𝐠𝐞𝐭𝐬 𝐢𝐭?
Any species can get this!

𝐖𝐡𝐚𝐭 𝐜𝐚𝐮𝐬𝐞𝐬 𝐢𝐭?
Mesothelioma in humans is overwhelmingly associated with exposure to 𝐚𝐬𝐛𝐞𝐬𝐭𝐨𝐬, a silicate based material used in construction. It is presumed that asbestos exposure may cause mesothelioma in animals as well. However, most of our animal species are not frequent visitors to construction sites! So most cases of mesothelioma in animals are presumed to be 𝐬𝐩𝐨𝐫𝐚𝐝𝐢𝐜, with no identifiable cause.

𝐖𝐡𝐲 𝐢𝐬 𝐭𝐡𝐢𝐬 𝐚 𝐩𝐫𝐨𝐛𝐥𝐞𝐦?
Mesotheliomas form nodular masses all over the body cavity lining. One of the main functions of the mesothelium is to produce small amounts of lubricating fluid, to keep the organs within the body cavity happy. Mesotheliomas can overproduce this fluid, which can interfere with normal organ function. This is particularly problematic in the pericardium, as excess fluid within the 𝐩𝐞𝐫𝐢𝐜𝐚𝐫𝐝𝐢𝐚𝐥 𝐬𝐚𝐜 (a sac around the heart) can prevent the heart from beating properly. In the most severe cases, animals will die suddenly because their heart simply can’t do its job!

𝐇𝐨𝐰 𝐢𝐬 𝐢𝐭 𝐝𝐢𝐚𝐠𝐧𝐨𝐬𝐞𝐝?
Diagnosis typically involves 𝐛𝐢𝐨𝐩𝐬𝐲 (taking a section of tissue) or 𝐚𝐬𝐩𝐢𝐫𝐚𝐭𝐢𝐨𝐧 (using a needle to collect cells) of one of the nodules. This allows the nodule’s cells to be examined under a microscope, to determine what type of cell they are. If they are a mesothelial cell, then a diagnosis can be made.

𝐇𝐨𝐰 𝐢𝐬 𝐢𝐭 𝐭𝐫𝐞𝐚𝐭𝐞𝐝?
Treatment typically involves a combination of 𝐜𝐞𝐧𝐭𝐞𝐬𝐢𝐬 (using a needle to remove fluid from a body cavity) to relieve pressure, and 𝐜𝐡𝐞𝐦𝐨𝐭𝐡𝐞𝐫𝐚𝐩𝐲 to try and control the tumours.