What is CD99 a marker for?

Antibodies to CD99 are used in diagnostic immunohistochemistry to distinguish Ewing’s sarcoma from other tumours of similar histological appearance, as well as for the identification of thymic tumours, and of spindle cell tumours, such as synovial sarcoma, haemangiopericytoma, and meningioma.

What is a blue cell tumor?

Desmoplastic small round cell tumors (DSRCTs, sometimes also referred to as small blue round cell tumor) are a type of sarcoma that usually develops in the belly or pelvis. They are most often found in white teenagers and young men between age 10 and 30. DSRCTs may cause pain or a mass in the belly.

What does synaptophysin positive mean?

Thus, synaptophysin is a specific and fairly sensitive marker for neuroendocrine tumors of both low and high grades of malignancy. The NF proteins are good markers for pheochromocytoma, and their presence is of basic tumor biologic interest and of potential diagnostic value in other neuroendocrine neoplasms.

What is the MIC2 gene?

MIC2 and XGR are the only known pseudoautosomal genes in man. MIC2 encodes the 12E7 antigen, a human cell-surface molecule of unknown function. XGR regulates, in cis,the expression of the XG and MIC2 genes.

What causes Dsrct?

Although researchers think a problem with the genes may cause DSRCT, this has not been proven. Since DSRCT often is not diagnosed until the cancer is advanced, tumors grow large and spread through the lymph system or blood stream to other parts of the body.

What are the small round blue cell tumors?

Small round blue cell tumours of childhood include neuroblastoma (NB), rhabdomyosarcoma, non-Hodgkin’s lymphoma, Ewing’s sarcoma and the closely related primitive neuroectodermal tumour (PNET) and the blastemic component of Wilms’ tumour.

Is desmin negative good?

Vimentin was coexpressed in a varying percentage of tumor cells in RMS of human and rat origin. The results show that desmin is an excellent marker for rhabdomyosarcoma, yielding few if any false-positive or false-negative results in frozen or alcohol-fixed material.

What does negative for desmin mean?

If the cells in your sample produce desmin, your pathology report will describe the cells as positive or reactive. If they do not produce desmin, your report will describe the cells as negative or non-reactive.

What is CD99 in sarcoma?

CD99 is a cell surface glycoprotein (also known as MIC2) that is recognized by the monoclonal antibody O13. Strong, diffuse membranous expression of CD99 is seen in nearly all Ewing sarcomas (Fig. 8.6).7 CD99 expression is unrelated to the gene products of the specific translocations found in Ewing sarcomas.

What is CD99L2?

CD99 and its paralog CD99-like 2 (CD99L2) are type I transmembrane proteins that are unrelated to any other known proteins (Bixel et al., 2010 ). CD99 is highly O -glycosylated and, like PECAM-1, is expressed by both leukocytes and endothelial cells ( Figure 7 (a) ).

Is CD99 a transmembrane protein?

CD99 and its paralog CD99-like 2 (CD99L2) are type I transmembrane proteins that are unrelated to any other known proteins (Bixel et al., 2010). CD99 is highly O -glycosylated and, like PECAM-1, is expressed by both leukocytes and endothelial cells (Figure 7 (a)).

What is the diagnostic significance of dot-like staining pattern in CD99?

Positivity for CD99 is not specific but its absence rules out Ewing sarcoma in the workup of a small blue round cell tumor Dot-like staining pattern has been reported in several disease entities but has so far not been proven to be diagnostically useful