Home Education AUAUniversity Education Products & Resources Pathology for Urologists Normal Histology and Important Histo-anatomic Structures Testis: Seminiferous Tubules and Interstitium

Testis: Seminiferous Tubules and Interstitium

Image A

Image B

  • Seminiferous tubules are highly convoluted tubules that contain 2 distinct cell populations 
    (image A) & (image B):
    • Spermatogenic cells
      • Germ cells in various stages of maturation (70-day process).
      • Maturation advances from basal to luminal aspect of ST.
      • Spermatogonia - 1° spermatocytes (largest cell, at mid portion) - 2° spermatocytes - spermatids - spermatozoa.
    • Sertoli cells
      • Essentially the "nurse" cells that support the germ cells.
      • Non-dividing columnar cells with oval or pyramidal nucleus located near the basement membrane.
      • Form tight junctions that compose the testis-blood barrier.
      • Produce Müllerian inhibiting factor in embryogenesis.
  • Important to distinguish these cells (particularly 1° spermatocytes and Sertoli cells) from atypical cells of intratubular germ cell neoplasia (large neoplastic cells usually next to basement membrane with prominent nucleolus, and is PLAP+, CD117+ and Oct3/4+).

Image C

Image D

  • Interstitium is the stroma between the seminiferous tubules and contains:
    • Leydig cells
      • Produce testosterone.
      • Have round nuclei with 1-2 prominent nucleoli and abundant bright pink (eosinophilic) cytoplasm (image C) & (image D).
      • The cytoplasm may contain lipofuscin pigment (golden-yellow) or cytoplasmic granules known as the crystals of Reinke.