Tryptase and trichrome stains of the liver in Case 1. (A) Pretreatment liver biopsy (100×) shows clustered MCs around a lymphoid nodule in the portal tract and increased spindled MCs in the lobule on tryptase immunostain. MCs constituted approximately 5% of the tissue. (B) Posttreatment liver biopsy (100×) shows much fewer MCs on tryptase immunostain (approximately 1% of the tissue). (C) Trichrome stain of the liver (100×) before treatment shows bridging fibrosis (with collagen staining blue) and early nodularity. (D) After treatment, trichrome stain of the liver (100×) shows improvement in fibrosis, now limited mainly to the portal tracts.