Purpose: Histological changes in lymph nodes simulating metastatic prostatic adenocarcinoma are reported.
Materials and methods: Lymph node frozen sections from 3 patients with prostatic cancer displayed marked histiocytosis. This tissue was subjected to histochemical, immunohistochemical and electron microscopic studies.
Results: Only 1 erroneous diagnosis of metastasis was made. All patients had hip prostheses for at least 6 years. Tissue replacing up to 80% of lymph nodes consisted of histiocytes containing large amounts of polyethylene.
Conclusions: Hip replacement predisposes the patient to have pelvic lymph node histiocytosis mimicking metastatic adenocarcinoma. This history should be communicated to the pathologist. Polyethylene is the most important factor in the cause of post-prosthesis lymph node histiocytosis.