Test Catalog

Test ID: CD34I    
CD34 Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

A marker of immaturity in the setting of acute myeloid leukemia or B lymphoblastic leukemia


The diagnosis of gastrointestinal stromal tumors, solitary fibrous tumors, and angiosarcomas

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

CD34 is 115 kDa membrane associated antigen found on human hematopoietic progenitor cells and vascular endothelial cells. In normal tonsil sections, antibodies to CD34 strongly stain vascular endothelial cells.


CD34 is used as a marker of immaturity in the setting of acute myeloid leukemia or B lymphoblastic leukemia. It is also useful in the diagnosis of gastrointestinal stromal tumors, solitary fibrous tumors, and angiosarcomas.

Interpretation Provides information to assist in interpretation of the test results

This test does not include pathologist interpretation; only technical performance of the stain. If interpretation is required order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut within 6 weeks.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Lopez-Nunez O, Surrey LF, Alaggio R, Fritchie KJ, John I: Novel PPP1CB-ALK fusion in spindle cell tumor defined by S100 and CD34 coexpression and distinctive stromal and perivascular hyalinization. Genes Chromosomes Cancer. 2020;59(8):495-499. doi: 10.1002/gcc.22844

2. Matoso A, Epstein JI: Epithelioid angiosarcoma of the bladder: A series of 9 cases. Am J Surg Pathol. 2015;39(10):1377-1382. doi: 10.1097/PAS.0000000000000444

3. Stanek J, Abdaljaleel M: CD34 immunostain increases the sensitivity of placental diagnosis of fetal vascular malperfusion in stillbirth. Placenta. 2019;77:30-38. doi: 10.1016/j.placenta.2019.02.001

4. Sardina LA, Piliang M, Bergfeld WF: Diagnostic value of CD34 and calretinin immunostaining in the diagnosis of proliferating tricholemmal tumor and trichoblastoma [published online ahead of print, 2019 Apr 23]. Int J Dermatol. 2019;10.1111/ijd.14461. doi: 10.1111/ijd.14461