A case of multicentric reticulohistiocytosis

Abstract

Fig. 2 e ‘Coral bead’ appearance at the nail beds. A 32 year old lady with no past commorbities presented with inflammatory deforming polyarticular arthritis of small and large joints, upper and lower limbs, symmetrically for last 2 years. She also had developed nodular and papular skin lesions simultaneously with the onset of the joint pains with low grade fever andweight loss of 10 kg in 2 years. Shehadactive synovitis with swollen and tender knees, elbows, metacarpophalangeal joints. She had ‘Piano hand’ deformities of hands (Fig. 1). Skin colouredpapulonodular lesionswereseenover extensor surface of forearms, knees, elbows, knuckle, proximal interphalangeal jointsofhandandpinna.The lesionsrangedfrom1 to5cm.Over the knees the nodules coalesced to give a ‘cobble stone appearance’. At the nail beds there was clustering of the small papules giving to the characteristic ‘coral bead’ appearance (Fig. 2). X-ray both handswithwrists showed a severe erosive arthritis (Fig. 3). Biopsy from her nodular skin lesions showed focal papillomatosis in the dermis and well circumscribed nodular zone comprised of sheets of histiocytes with epitheloid and xanthomatous change. Majority of histiocytes had abundant granular eosinophilic cytoplasm (oncocytic histiocytes) consistent with reticulohistiocytosis. Patient was put on treatment with methotrexate15mg/week þ lefunomide 10 mg/day.