Figure 1

Microscopic lesions found in the scrotal skin, pampiniform plexus and testicular parenchyma tissue sections from chronically infected bulls. Lesions were visualized by either haematoxylin–eosin (H-E) or Masson’s trichrome (M-T) staining. A (H-E) Hyperkeratosis, acanthosis and dilated sweat glands associated with tissue cysts in the scrotum (bull no. 17); B (M-T) Hyperkeratosis and abundant fibrosis associated with tissue cysts in the scrotal skin (bull no. 12); C (H-E) Hyperkeratosis and numerous tissue cysts surrounded by connective tissue and abundant inflammatory infiltrate in the scrotal skin (bull no. 16); D (H-E) Tissue cysts in the lumen of the vessels associated with the scarce inflammatory reaction in the pampiniform plexus (bull no. 17); E (M-T) Abundant fibrosis associated with tissue cysts in the pampiniform plexus (Masson’s trichrome stain) (bull no. 17); F (H-E) Higher number of tissue cysts in the lumen of the vessels associated with the scarce inflammatory reaction in the pampiniform plexus (bull no. 8) G: (H-E) Degenerated seminiferous tubules and absence of sperm (bull no. 10); H (M-T) Tissue cysts with fibrosis and the inflammatory reaction in one of them (black arrows) and seminiferous tubules with different degrees of atrophy inside (Masson’s trichrome stain) (bull no. 13); I (H-E) Tissue cysts necrotic with inflammatory infiltrate, degenerated seminiferous tubules and the absence of sperm and fibrosis (bull no. 13). Scale bars: A, C, D, F, G: 200 µm; B and E: 100 µm.