Metallosis of Lymph Node

Related Cases: HP-0316

Clinical Futures

  • Lymphadenopathy associated with joint prostheses

  • Due to use of metal or cementing prostheses to replace large joints, mostly hip and knee

  • Often involves inguinal and pelvic lymph nodes, and also bone marrow, liver, and spleen

  • Birefringent Cementing materials, mainly polyethylene

  • Grossly, cut surface of lymph nodes dark brown or black

Microscopic Findings

  • Markedly distended sinuses filled with abundant histiocytes

  • Large histiocytes with vacuolated, foamy, or totally clear cytoplasm; may form coalescing nests and sheets

  • Histiocytes contain metal particles or polyethylene

  • Metal particles: Black, nonrefringent, 0.5-2 μm, or rarely100 μm

  • Polyethylene: Transparent, birefringent, 0.5-50 μm slender needles or flakes

  • Histiocytes PAS+

Differential Diagnosis

  • Reactive Sinus Histiocytosis

    • Nonspecific reactive changes

    • Slight expansion of sinuses by histiocytes

    • Histiocytes lack abundant foamy cytoplasm or foreign bodies

  • Metastatic Carcinoma

    • History of carcinoma in other organs, including prostate, bladder, uterine cervix, breast or GI tract

    • Tumor cells may show sinusoidal infiltrative pattern and can morphologically resemble histiocytosis

    • Tumor cells usually more cohesive with cytologic atypia

    • Cytokeratin+

  • Rosai-Dorfman Disease

    • Markedly expanded sinuses

    • Large histiocytes with abundant cytoplasm, prominent central nucleus and emperipolesis

    • Histiocytes S100+, CD1a-

  • Whipple Disease

    • Tropheryma whipplei

    • Fever, diarrhea, weight loss, and mesenteric lymphadenopathy

    • Expanded sinuses containing large cystic spaces and large histiocytes with foamy cytoplasm

    • Histiocytes PAS/D+, AFB-

    • PCR positive for T. whipplei



Last update: 05/20/2015