Ultrastructural and histochemical investigations of spindle-shaped corpuscles in phagocytic cells of lymph nodes.

In connection with various diseases, spindle-shaped or roundish 2-15 micrometer large corpuscles with a yellowish-green, partly brown color are found in phagocytic cells of lymph nodes of various localisation. There are three groups according to staining and ultrastructural characteristics. I. Strongly Fe+++ positive corpucles only, 2. corpuscles with a positive PAS-reaction, Ziehl-Neelsen and Sudan black B stain and slight iron adsorption, 3. particles with irregular stainability. Ultrastructurally, the spindle bodies of Group I have a uniform membrane, double in some sections and a narrow, finely granular rim, in which 50 A large iron micelles are stored. The electrondense center contains structures which may correspond to remainders of cell organelles. The similarly shaped particles of Group 2 have a homogeneous, electron-dense center and sometimes half-moon-shaped, homogeneous, less dense appositions. A dense round center with finely honey-combed translucencies and marginal vacuoles characterizes the irregularly shaped, in part spindly corpuscles of Group 3. The energy-dispersion X-ray analysis indicates only iron for the particles of Group I. A relation of the corpuscles to specific diseases, especially to sarcoidosis and certain therapeutic measures, is not evident.