Abstract
BACKGROUND: Multicentric reticulohistiocytosis (MRH)/systemic lupus erythematosus (SLE) overlap syndrome is an uncommon disease in the clinic and is diagnosed through characteristic clinical manifestations, histopathology, and immunopathology. Here, we report the case of a 30-year-old woman with SLE who developed MRH. CASE SUMMARY: A 30-year-old woman with a history of polyarthritis for the past 12 years had multiple skin nodules on her body for 10 years, including the sacrococcygeal area, dorsum of the hands, interphalangeal joint of the feet and sternoclavicular joint. The histopathology of a biopsy of the distal interphalangeal joint of the hands revealed granulomatous inflammation, fibrous hyperplasia with ground-glass degeneration, inflammatory cell exudation and focal necrosis. The immunohistochemical stains showed positive staining for CD68 and negative staining for S100 and acid-fast staining. The patient was diagnosed with SLE with MRH. Her symptoms were improved after a combined treatment of prednisone, hydroxychloroquine and cyclophosphamide. CONCLUSION: MRH/SLE overlap syndrome is difficult to diagnose and treat. Cyclophosphamide may be an alternative choice for the treatment of MRH.