Metallosis of Lymph node

• 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.

• Microscopic features:

  • The sinuses are markedly distended, and are filled with large foamy histiocytes.

  • 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 light.