Fig. 4.

Immunoperoxidase stains (kappa and lambda); tubular findings. A, B (Immunoperoxidase technique-A: Kappa light chain, B: Lambda light chain ×100): The same core as in Fig. 2A; the plasmacytic infiltrate and inclusions showing positivity for kappa light chains rather than lambda. C, D (IP-C: Kappa light chain, D: Lambda light chain ×200): The arrowheads are pointing to intratubular cytoplasmic inclusions that are positive for Kappa (Fig. 2C) and negative for Lambda (Fig. 2D). The arrows are pointing to interstitial plasmacytic infiltrate that is also positive for Kappa (Fig. 2C) and negative for Lambda (Fig. 2D)