Test Method


CPT Code

88342 x 1
88341 x 1

Stains / Test Description

Smooth muscle actin antibody binds to smooth muscle cells and myoepithelial cells. It stains the muscularis propria and muscularis mucosae of the gastrointestinal tract, the uterine myometrium, medial layer of blood vessels, myoepithelial cells of salivary glands and other organs. The antibody does not stain skeletal and cardiac muscle, endothelium, connective tissue, epithelium or nerve. The antibody can be used to identify smooth muscle tumors (leiomyomas and leiomyosarcomas).

Specimen Requirements

(1) H&E slide with formalin-fixed, paraffin-embedded (FFPE) tissue, fixed with 10% NBF.
One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4 microns) for each test/antibody ordered

Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.

Storage & Transport

Ship specimen same day (whenever possible) with refrigerated (not frozen) cold pack

Turnaround time

1-3 days depending on level of service

Level of Service

Global (with interpretation)
Slide Only (glass slides only)
Web-Enabled (glass and digital images through eCSI portal)