Due to use of metal prostheses to replace large joints.
The presence of metal-wear debris can be seen in local and distant
lymph nodes, bone marrow, liver, and spleen.
Grossly, the cut surface of the enlarged lymph nodes appears dark
brown or black.
The sinuses are markedly distended, and are filled with large
The histiocytes are vacuolated, foamy, or totally clear. They are
PAS+ and may form coalescing nests and sheets.
The histiocytes contain polyethylene or silicone. In addition,
they also contain metal particles in the shape of needles or ﬂakes.
These particles are 0.5 to 5 μm in largest dimension, irregularly
shaped, and black on HE staining. Some particles may be up to 100
μm and are usually contained in large, multinucleated giant cells.
The metal particles are strongly birefringent under polarized