Description
Why It’s Done:
• To diagnose Ewing’s sarcoma: The CD99 test is most commonly used to identify Ewing’s sarcoma, which typically shows strong expression of CD99. This test helps differentiate it from other cancers with similar clinical features.
• To confirm tumor origin: In some cases, the CD99 test is used to confirm the origin of a tumor when its type or tissue origin is uncertain. The test can help identify undifferentiated tumors or soft tissue sarcomas.
• To assist in the diagnosis of other cancers: CD99 is also used to diagnose other tumors such as primitive neuroectodermal tumors (PNETs), which share similar characteristics with Ewing’s sarcoma and can express CD99 as well.
• To differentiate between tumors: The CD99 test can help distinguish between Ewing’s sarcoma and other types of tumors that might look similar under a microscope but do not express CD99.
• To evaluate tumor spread: In certain cancer types, the CD99 test can provide valuable information about the spread of disease and may aid in staging or monitoring cancer progression.
Preparation:
• Fasting: Fasting is not required for the IHC – CD 99 test.
• Tissue sample: The CD99 test requires a tissue sample, typically obtained via a biopsy, which could be taken from a suspicious lump, tumor, or bone marrow (depending on the suspected cancer).
• Medications: Inform your healthcare provider about any medications you are currently taking. While the CD99 test itself is not influenced by medications, certain drugs may impact the collection of tissue samples or the overall diagnosis process.
• No special preparation: Generally, there are no dietary or lifestyle restrictions before the test, but you may need to follow specific instructions from your healthcare provider regarding the biopsy procedure
