Sinus histiocytosis mimicking metastatic melanoma in lymph nodes of a patient with a large joint prosthesis: Case report and review of the literature

Abstract

Malignant melanoma metastases to regional lymph nodes may be mimicked by several non‐neoplastic processes, including sinus histiocytosis induced by fragments shed from joint prostheses. A patient who had an elective lymph node dissection for malignant melanoma and was found to have “post‐prosthesis lymph node histiocytosis” resembling metastatic disease is described. Knowledge of the patient's past history of a total shoulder joint replacement along with the use of polarized light microscopy to identify birefringent particles of prosthetic debris allows for an accurate histologic diagnosis.