Multicentric Reticulohistiocytosis - A Rare Clinicopathological Entity

Abstract

This is a rare case report of a thirty-eight-year-old male who presented with multiple asymptomatic hyper-pigmented papulonodular lesions on the face for the past two years without the association of pain or pruritus and with restriction of elbow movements. The diagnosis of multicentric reticulohistiocytosis was made on histopathological findings of Touton type of giant cells and sheets of foamy histiocytes along with immunohistochemistry (IHC) studies. Workup was done for other associated diseases. Multicentric reticulohistiocytosis (MRH) is also known as lipoid dermatitis,1 a rare disease which is characterised by the presence of extensive papulonodular cutaneous eruptions and severe, sometimes destructive arthropathy, followed by eruption of the skin and mucous membrane lesion.2,3 It’s a rare idiopathic nonLangerhans cell histiocytosis.4 This disorder is characterised by predominant cutaneous manifestation and joint involvements. The lesions may show regression and recurrence, many case studies show an association of this lesion with internal malignancies, autoimmune diseases, hyperlipidaemias, and tuberculosis.5,6 Few cases have shown musculoskeletal involvement with features such as myositis. The disease was described initially as reticulocytosis granuloma in 1952 by Caro and Senear, later the term was coined by Goltz and Laymon as multicentric reticulohistiocytosis in 1954.4 It is also known by different names such as giant cell histiocytosis, lipoid dermato-arthritis, lipoid-rheumatism and reticulohistiocytosis granuloma. The disease incidence is very low worldwide, less than 200 cases have been reported in literature5 and reports from India are limited.