View source for CD99

'''CD99''' is a commonly available [[immunostain]] with various uses. It stains a lot of different tumour and has been described by one soft tissue pathologist as ''slutty''.

==Positive==
===Membrane staining===
*[[Ewing sarcoma]] - diffuse (plasma membrane) staining.
*Lymphoblastic lymphoma/leukemia.
*[[Angiomatoid fibrous histiocytoma]].
*[[Desmoplastic small round cell tumour]].

===Weak/cytoplasmic staining===
*[[Synovial sarcoma]].
*[[Rhabdomyosarcoma]].
*[[Rhabdoid tumour]].

===Others===
*[[Malignant melanoma]] (9 of 10 cases<ref name=pmid11789717>{{Cite journal  | last1 = Monteagudo | first1 = C. | last2 = Calduch | first2 = L. | last3 = Navarro | first3 = S. | last4 = Joan-Figueroa | first4 = A. | last5 = Llombart-Bosch | first5 = A. | title = CD99 immunoreactivity in atypical fibroxanthoma: a common feature of diagnostic value. | journal = Am J Clin Pathol | volume = 117 | issue = 1 | pages = 126-31 | month = Jan | year = 2002 | doi = 10.1309/2EXB-70CW-3U6P-VQ6H | PMID = 11789717 }}</ref>).
*[[Atypical fibroxanthoma]] (19 of 26 cases<ref name=pmid11789717/>).

==Negative==
*[[Squamous cell carcinoma]].<ref name=pmid11789717/>
*[[Undifferentiated small round cell sarcoma with t(4;19)]] (CIC-DUX sarcoma) - negative or weak positive.

==See also==
*[[Immunohistochemistry]].

==References==
{{Reflist|1}}


[[Category:Immunohistochemistry]]