What are the CD34+ cells in benign peripheral nerve sheath tumors? Double immunostaining study of CD34 and S-100 protein

Am J Clin Pathol. 2000 Jul;114(1):123-6. doi: 10.1309/C7N9-J2AU-5TB9-5FRL.


To determine whether CD34 expression in nerve sheath lesions was found in a unique cell population or in a subset of nerve sheath cells, we performed double immunohistochemical staining using a standard avidinbiotin complex method with 2 separate color developing systems. We studied 40 neurofibromas and 16 neurilemomas. All lesions strongly expressed S-100 in nuclei and cytoplasm. CD34 was detected in cells having ameboid dendritic cytoplasm present in greatest numbers in Antoni B zones of neurilemomas, myxoid zones of neurofibromas, at the periphery of lobules in both tumor types, and condensed in apposition to perineurium. The CD34+ cells also were detected in normal nerves. They were infrequent in Antoni A zones of neurilemomas. No dual S-100 and CD34 expression was seen. This double immunostaining confirms the presence of a CD34-reactive non-Schwannian cell type in these neural neoplasms. As the CD34+, S-100-negative cell population is present also in normal nerves and infrequently seen in the areas of cellular neoplastic Schwann cells, CD34+, S-100-negative cells in peripheral nerve sheath tumors most likely are nonneoplastic and may have a supportive function.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antigens, CD34 / analysis*
  • Female
  • Humans
  • Immunohistochemistry / methods
  • Male
  • Middle Aged
  • Neurilemmoma / immunology*
  • Neurilemmoma / pathology
  • Neurofibroma / immunology*
  • Neurofibroma / pathology
  • Peripheral Nervous System Neoplasms / immunology*
  • Peripheral Nervous System Neoplasms / pathology
  • S100 Proteins / analysis*
  • Staining and Labeling


  • Antigens, CD34
  • S100 Proteins