Cardiac engagement in multicentric reticulohistiocytosis: report of a case with fatal outcome and literature review.

Multicentric reticulohistiocytosis is a rare systemic disorder of unknown etiology characterized by severe destructive arthritis, development of cutaneous nodules and is in many cases associated with malignancy. In multicentric reticulohistiocytosis polyarticular, symmetric, erosive arthritis is common and progresses to mutilans arthritis in 45% of cases. Skin lesions are characterized by typical nodular manifestations and plaques containing lipid-laden (Periodic Acid Schiff positive) histiocytes and multinucleated giant cells [1]. In multicentric reticulohistiocytosis involvement of other organs (such as heart, lungs, liver, kidney, thyroid, bone marrow and muscles) and systemic symptoms (like fever and weight loss) have been described less commonly [2]. We report a case of multicentric reticulohistiocytosis with mutilans arthritis, later cardiac engagement and fatal outcome in spite of therapy. In August 2000 a 37-year-old woman was referred to our Rheumatology Unit. She manifested cutaneous reddish-brown nodules, 2-10 mm in diameter, on the fingers of her right hand and on the palms of both hands, on her elbows, face and legs, and in her oral mucosa. Morning stiffness was also present, lasting for 2 h, and accompanied by pain in the proximal, metacarpophalangeal and interphalangeal joints in the hands, in the wrists, shoulders and knees with additional character. Laboratory data showed: ESR 32 mm/h, CRP 0.76 mg/ dl, routine and autoimmunity tests (autoantibodies and immunocomplexis) negative. Examination of the knee synovial fluid sample evidenced 6,400 mm leucocytes. Radiological examination of the hands and feet evidenced an area of bone rarefaction at the base of the distal phalanx of the left hand third finger and the right hand second finger, and at the trapezio-metacarpal joints, with juxtarticular osteoporosis. Histologic study of the nodules showed the typical picture of multicentric reticulohistiocytosis with the presence of PAS positive histiocytes, multinucleated giant cells, fibroblasts and lymphocytes (Fig. 1). Under electronic microscopy (ME) examination the giant cells showed numerous electrodense grains. The patient started therapy with methylprednisolone 8 mg/day and methotrexate 10 mg/week. In spite of this therapy the arthritis became destructive, therefore the dose of methotrexate was modified to 15 mg/week. The patient also received six cycles of methylprednisolone 1 g for 3 days and cyclophosphamide 750 mg/m on day hospital regimen. During the subsequent 3 years the disease progressively showed a mutilans feature with separation of the bone segments and consequent shortening and skin folding of the fingers (Fig. 2). Initially, marginal erosion of the knee, femoral and tibial condyles and a medullary area of the tibial diaphysis were observed. The shoulder joints showed destruction of the humerus heads and the same aspect was observed in the elbows. The left hip joint showed resorption of the femoral neck and radiological controls showed the collapse of the M. Benucci (&) Section of Rheumatology, Nuovo Ospedale S. Giovanni di Dio, ASL 10 Florence, Via di Torregalli 3, 50143 Florence, Italy e-mail: [email protected]; [email protected]