Angiomyolipoma of the Kidney: Its Positive Expression of Immunohistochemical Markers for Schwann Cell Differentiation

Abstract

Ten cases of renal angiomyolipomas were immunohistochemically analyzed for the presence of S-100 protein, neuron specific enolase (NSE) and desmin using the avidin-biotin complex method. The composition of histologic constituents differed in each case. The cases with predominantly smooth muscle-like solid spindle cell proliferation showed unexpected positive reaction to S-100 protein and NSE. Among 10 cases, five were both S-100 protein positive and NSE positive. The reaction pattern of S-100 protein and NSE was similar. Relatively weak or minimal positive reactions to desmin were observed in the cases and the distribution of positive reaction was different from those of S-100 protein and NSE. The result demonstrated immunohistochemical evidence of neural or Schwarm cell differentiation in a significant proportion of renal angiomyolipomas, and its histogenesis was speculated.