Multicentric reticulohistiocytosis presenting with destructive polyarthritis, laryngopharyngeal dysfunction, and a huge reticulohistiocytoma

Multicentric reticulohistiocytosis (MRH) is a rare multisystemic disease presenting with skin lesions and erosive polyarthritis and is often associated with malignancy. We describe a 60-year-old woman with diffuse papulonodular skin eruptions and progressive osteolytic bone damage over the bilateral hands, humeral head, and acromioclavicular joints within 2 years. Moreover, dysphagia and a hoarse voice occurred in this patient and an unusual huge mass-reticulohistiocytoma-developed over the left upper back. Tissue biopsy of the skin lesions, laryngeal nodules, and this large mass showed infiltration of numerous CD68(+) histiocytes and multinucleated giant cells with abundant eosinophilic ground-glass cytoplasm. Combination therapy with steroids and methotrexate improved her cutaneous, joint, and laryngopharyngeal symptoms. The large reticulohistiocytoma resolved with methylprednisolone pulse therapy. This polyarthritis, which can be confused with rheumatoid arthritis, can be diagnosed by careful immunohistochemical examination of biopsies. To prevent the irreversible disease process, early and aggressive therapy is necessary.