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).
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.
Leydig cell hyperplasia: Clusters of Leydig cells in intervening interstitium, unlike LCT are small (<0.5 cm) and multifocal.