Leydig Cell Tumor : Calretinin

Comments:
Calretinin is a calcium binding protein that was initially discovered in the neurons. It plays a role in calcium signaling. It is quite useful in distinguishing malignant mesothelioma (calretinin-pos) from adenocarcinoma.

The image shows cytoplasmic and nuclear staining for calretinin in a Leydig cell tumor of the testis.