CD 141 or thrombomodulin is a transmembrane glycoprotein and can be demonstrated in both benign mesothelium and in endothelial cells and can be used to help differentiate mesothelioma from adenocarcinoma, especially useful in lung tumours. CD141 positivity has been seen in lining cells of arteries, veins, capillaries and the lymphatics as well as mesothelial cells, meningeal lining cells, synovial cells, megakaryocytes and platelets.

The staining pattern of CD141 is Membraneous and Cytoplasmic as shown below.

Picture 1 – CD141 positivity in Lymph node

 

CD141 has several different applications. Below are a few examples.

Tumour or cell type	CD141 + or -
Malignant Mesothelioma	Positive
Urothelial carcinoma	Positive
Adenocarcioma	Negative
Prostate Carcinoma	Negative