All IHC stains will include a positive control tissue

• 30-60% of B-ALL and AML's are positive for CD34
• CD34 is a sensitive, but nonspecific marker of vascular neoplasms
• CD34 has been shown useful in differentiating dermatofibroma (DF) from DFSP. CD34 is positive in the majority of cases of DFSP and negative in dermatofibromas
• CD34 has been identified in benign neural tumors such as neurofibromas, neuromas, and schwanomas¹
• CD34 has been shown to be useful in differentiating solitary fibrous tumors of the pleura (SFT) from desmoplastic mesotheliomas. CD34 is positive in SFT and negative in mesotheliomas. Also included in the panel to differentiate these two lesions is Vimentin (positive in both) and CK (positive only in mesothelioma)²
• CD34 is useful in identifying gastrointestinal stromal tumors (GIST). Most GIST's may lack expression of all markers (including smooth muscle markers) except CD34

Submit a formalin-fixed, paraffin-embedded tissue

Formalin-fixed, paraffin-embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• CD34 is a glycoprotein associated with human hematopoietic progenitor cells
• CD34 is present on immature hematopoietic precursor cells and all hematopoietic colony-forming cells in the bone marrow and blood
• CD34 is absent on fully differentiated hematopoietic cells
• In normal tissue, CD34 is present on endothelial cells, dermal dendritic cells, endoneurium of peripheral nerves and around dermal adnexal structures

Staining pattern

• Cytoplasmic

References

1. Weiss et. al.; CD-34 Is Expressed by a Distinctive Cell Population in Peripheral Nerve, Nerve Sheath Tumors and Related Lesions; American Journal of Surgical Pathology 17(10): 1039-1045, 1993.
2. Flint, et. al.; CD34 and Keratin Expression Distinguishes Solitary Fibrous Tumor (Fibrous Mesothelioma) of Pleura Form Desmoplastic Mesotheliomas; Human Pathol. 26:428-431, 1995