Test Method


CPT Code

88342 x 1
88341 x 1

Stains / Test Description

CD117 (cKit) is a transmembrane receptor tyrosine kinase. It is expressed in many tissues and cells, such as tissue mast cells, skin basal cells, melanocytes, breast glandular epithelial cells, dermal sweat gland, esophageal glands, testicular and ovarian interstitial cells. Abnormal expression of cKit has been implicated in pathogenesis of myeloid leukemias. cKit expression has also been demonstrated in solid tumors including gastrointestinal stromal tumor (GIST), melanomas, breast carcinomas and small cell lung carcinoma. C-Kit pharmDXTM is indicated as an aid in the differential diagnosis of GIST. Accurate assessment of CD117 protein expression using cKIT testing is a critical factor in the diagnosis of GIST and is becoming increasingly important in clinical management, including the use of imatinib mesylate (Gleevec®) therapy.

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)