Multicentric Reticulohistiocytosis (MRH): First Case Report with Tenosynovial Fluid Analysis and Tenosynovial Histology Demonstrating the Classic Histologic Findings

Multicent ricreticulohistiocytosis (MRH) is a rare systemic disease of unclear etiology characterized by destructive, deforming arthritis, nodules in the skin, mucous membrane and internal organs and can be associated with malignancy. The tenosynovial fluid and tenosynovium histologic findings have not been reported in any case reports of MRH in the literature. To our knowledge, this is the first case report of tenosynovial fluid and tenosynovium demonstrating the classic histologic findings of histiocytes with a foamy eosinophilic cytoplasm. This case also demonstrates a non-deforming arthritis.