Table of Contents
Immunohistochemical methods have localized chromogranin in a wide variety of endocrine tissues such as the pituitary, pancreas, hypothalamus, and parathyroid. Neuroendocrine cells exhibit a fine granular immunoreactivity to anti-chromogranin. It is generally accepted that the co-expression of certain keratins and chromogranin mean neuroendocrine lineage. The presence of strong anti-chromogranin staining and absence of anti-keratin staining should raise the possibility of paraganglioma. The co-expression of chromogranin and NSE is typical of neuroendocrine neoplasms. Most pituitary adenomas and prolactinomas readily express chromogranin.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type or one (1) unbaked, unstained slide cut at 4-5 microns for H&E staining (required) and two to three (2-3) positively charged unstained slides cut at 3-4 microns for each test/antibody ordered.
Storage and Transport
Use cold pack during transport of paraffin blocks and unstained slides. Cold pack should not be placed in direct contact with the specimen during shipping.
Specimen Rejection Criteria
All specimens must be submitted according to the test directory instructions. Before submitting specimen, please carefully review specimen requirements.
Listed below are possible causes for delays in specimen processing or possible specimen rejections or cancellations:
- No patient identification on requisition form
- No patient identification on specimen container or slides
- No referring provider
- No account information provided
- No test ordered on requisition
- No specimen source provided
- Inappropriate specimen type
- Insufficient volume for analysis
- Inappropriate specimen container
- Improper specimen transport
- Specimen leaked in transport
- Specimen submitted in incorrect or expired transport media
- Slides broken beyond repair on receipt
- Conflict between patient name on specimen and requisition form
- Specimen not properly preserved
- Sample containing a needle
A representative from Client Services will attempt to contact your office to resolve specimen problems. Additional documentation may be requested from your office to be returned by fax. In the event that resolution is not possible, the specimen may be returned to your office.
Turn Around Time (TAT)
88341, 88342, 88360