CD99

Alias/Synonym: Ewing Sarcoma, PNET

CPT Code: 88342

Includes:

Specimen Type, Preferred:

Formalin fixed paraffin embedded tissue

Specimen Type, Alternate:

Sample Quantity, Preferred:

1 block

2 slides

Sample Quantity, Minimum:

N/A

Transport Container:

Paraffin block

Unstained slides

Transport Temperature:

Room temperature

Collection Instructions:

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

Slides should be positively charged and cut at 3-4 microns for each stain/antibody ordered.

Specimen Stability:

N/A

Rejection Criteria:

No liquid specimens.

Uncharged slides

Clinical Significance:

CD99 is a 32 kDa transmembrane glycoprotein, encoded by the MIC2 gene, which is located in the pseudoautosomal region of the human X and Y chromosomes.  Recently, the MIC2 gene has been shown to encode two distinct proteins which are produced by alternative splicing of the CD99 gene transcript and are identified as bands of 30 and 32 kDa (p30/32).  Although its function is not fully understood, CD99 has been implicated in various cellular processes including homotypic aggregation of T cells, upregulation of T cell receptor and MHS molecules, apoptosis of immature thymocytes and leukocyte diapedesis. CD99 is reported to be expressed on most human tissues including cortical thymocytes, pancreatic islets cells, Leydig and Sertoli cells, virtually all hematopoietic cell types (except granulocytes), peripheral blood lymphocytes, granulose cells of the ovary, endothelial cells and basal/parabasal squamous epithelial cells. CD99 expression has been reported in a wide range of tumors, including Ewings sarcoma and T cell lymphoma, but is not very specific.

Limitations:

Turnaround Time:

1 day(s)

Reference Ranges:

N/A

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