A regulatory protein found in smooth muscle and tissues which interacts with actin, myosin, tryopomyosin, and calmodulin. It is a useful marker of smooth muscle and detects tumors of smooth muscle, myofibroblastic, and myoepithelial differentiation. It is also useful in the identification of leiomyosarcoma and is also useful in the differentiation of epitheliioid mesothelioma from serous papillary carcinoma of the ovary. It is generally negative in endometrial stromal tumors.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen typeorOne (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody orderedBlock and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.