Fig. 2

Immunohistochemical expression and distribution of amyloid deposits (a to e), and characteristics of free bodies and macrophages in other regions of the epididymal lumen (f to k). Expression in the amyloid deposits of transthyretin (a), light chain kappa (b) and lambda (c), amyloid P (d) and pan CK AE1 AE3 (e) is observed. Note the presence of epithelium-lined (arrows) (intraluminal) and non-epithelium-lined (interstitial) amyloid deposits. In C, the intraluminal and interstitial deposits are organized in a similar convoluted path to that of the epididymal tubule. In E, residual pan CK AE1 AE3+ epithelial cell bands persist in the periphery of the interstitial deposits. In other regions of the epididymal lumen, free amyloid bodies in the lumen associated with vesicles, particles and filaments are present (f to h). Note Congo red positivity (f) with yellow-green birefringence (g) and immunohistochemical expression of amyloid P (h). Intraluminal CD68 positive macrophages (i) showing PAS positive intracytoplasmic granules (j), which express amyloid P (k), are also observed. a, b, d and e correspond to case 2. c and f to k correspond to case 3. a, b, d and e: ×120, c: ×10, f, g, I and j: ×320, h and k: ×480