Home Education AUAUniversity Education Products & Resources Pathology for Urologists Testis Sex Cord Stromal Tumors Leydig Cell Tumor

Leydig Cell Tumor

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  • Most common type of SCST.
  • Comprises 1-3% testicular tumors.
  • 2 age peaks: 5-10 years old and 30-35 years old.
  • A few are seen in cryptorchidism.
  • Presents a painless testicular mass.
  • Tumor cells may produce androgen, estrogens or both and presents with gynecomastia or precocious puberty; symptoms usually regress with excision.
  • Gross: Golden-brown to yellow or gray-white cut surface (ave. 3 cm) (image A).

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  • Histology:
    • Large, round or polygonal cells with abundant pink or vacuolated cytoplasm and well-defined cell borders (image B), (image C), & (image D).
    • Round or ovoid nuclei, prominent nucleoli, rarely binucleated or multinucleated.
    • Intracellular eosinophilic crystalloids or Rienke crystals (40%), lipofuscin pigment (15%).
    • Growth patterns: solid (most common), insular, tubular, ribbon-like, and pseudofollicular.
  • Mostly are benign tumors; 10% are malignant.
  • DDX:
    • Leydig cell hyperplasia: Clusters of Leydig cells in intervening interstitium, unlike LCT are small (<0.5 cm) and multifocal.