Multicentric Reticulohistiocytosis
David S. Cassarino, MD, PhD
Key Facts
Terminology
Giant cell reticulohistiocytosis
Clinical Issues
Most cases occur in adults > 40 years old
Multiple nodules and arthropathy
Prognosis is variable; some cutaneous lesions may regress
Osteoarticular involvement shows progressive course in 1/2 of cases
Microscopic Pathology
Dermal-based nodular proliferation of large mononuclear and multinucleated histiocytes
Cells show characteristic abundant glassy/hyalinized-appearing eosinophilic cytoplasm
Occasional Touton-type giant cells containing lipid may be present but not prominent
There is often overlying epidermal atrophy
 Low-power examination shows a dermal-based proliferation containing numerous enlarged histiocytic-appearing cells associated with a background mixed inflammatory infiltrate. |
 Higher magnification shows a population of enlarged histiocytic cells with abundant dense eosinophilic cytoplasm and 1 to several oval to reniform nuclei. |
TERMINOLOGY
Abbreviations
Multicentric reticulohistiocytosis (MCR)
Synonyms
Giant cell reticulohistiocytosis
Reticulohistiocytosis of skin and synovia
Definitions
Proliferation of large histiocytes with dense eosinophilic cytoplasm involving multiple organs
ETIOLOGY/PATHOGENESIS
Associated Conditions
Association with autoimmune disorders and internal malignancies
CLINICAL ISSUES
Epidemiology
Age
Most cases occur in adults > 40 years old
