Stains & CD markers
CD34


Last author update: 8 September 2023
Last staff update: 8 September 2023

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PubMed Search: CD34

Wiebke Solass, M.D.
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Cite this page: Solass W. CD34. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd34.html. Accessed April 15th, 2024.
Definition / general
  • 110kDa glycosylated transmembrane protein
  • Marker of vascular endothelial cells
  • Sensitive but not specific marker for neoangiogenesis
  • May mediate attachment of hematopoietic stem cells to bone marrow extracellular matrix or directly to stromal cells, although specific function is unknown
Essential features
  • Good marker for neoangiogenesis
  • Helpful to distinguish liver lesions (focal nodular hyperplasia [CD34-] versus hepatocellular carcinoma [CD34+ in sinusoidal spaces])
  • Screening marker to differentiate between soft tissue neoplasms
  • Marker for hematopoietic progenitor cells - blasts
Terminology
  • Hematopoietic progenitor cell antigen CD34
  • CD34+ stromal cells are called dendritic interstitial cells
Pathophysiology
  • Intercellular adhesion protein and cell surface glycoprotein; ligand is CD62L (L selectin)
  • May mediate attachment of hematopoietic stem cells to bone marrow extracellular matrix or directly to stromal cells, although specific function is unknown
  • CD34 staining defines adult hematopoietic stem cells but CD34+ cells can also differentiate into neural cells (Exp Neurol 2006;197:399)
Interpretation
  • Membranous stain
  • Endothelium acts as a positive internal control
  • Staining represents presence of protein, not cross reactivity, despite wide range of tissues that are CD34+ (Am J Pathol 2000;156:21)
Uses by pathologists
Prognostic factors
Microscopic (histologic) description
  • Membranous
Microscopic (histologic) images

Contributed by Wiebke Solass, M.D., Andrey Bychkov, M.D., Ph.D. and Cases #126 and #130

GIST in cytological block material

Solitary fibrous tumor

Spindle cell lipoma


Dermatofibrosarcoma protuberans

Prominent vascular network

Capillary network

Missing Image

Pre-B ALL, kidney

Missing Image

Myeloid sarcoma, bone

Positive staining - normal
Positive staining - disease
Negative staining
Sample pathology report
  • Left thoracic tumor, resection:
    • Spindle cell lipoma (maximum 11.5 cm) (see comment)
    • MDM2 FISH: negative (no gene amplification)
    • Comment: In combination with the additional molecular examinations, the findings fit primarily with a spindle cell lipoma (MDM2 negative and CD34 positive). There is no evidence for liposarcoma / atypical lipomatous tumor and the criteria for the diagnosis of an atypical spindle cell lipomatous tumor are not fulfilled.
Board review style question #1


If positive, which marker can support the diagnosis of a gastrointestinal stromal tumor (GIST)?

  1. CD34
  2. Desmin
  3. EMA
  4. S100
  5. SMA
Board review style answer #1
A. CD34. Under the given answers CD34 is the distinguishing marker for soft tissue neoplasms and in the majority of GIST positive. Other markers supporting the diagnosis of GIST are DOG1 and c-KIT (CD117). Answers B and E are incorrect because desmin and SMA are usually negative in GIST but positive in leiomyoma. Answer D is incorrect because S100 is a strong marker for neuronal differentiation and should be negative in GIST (Curr Opin Gastroenterol 2019;35:555). Answer C is incorrect because EMA is highly expressed in carcinomas and not in GIST.

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Reference: CD34
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