Mixed connective tissue disorder and Castleman's disease.

We present a 16-year-old girl who presented with polyarthritis in association with Raynaud's phenomenon, malar rash, oral ulcers, photosensitivity and alopecia of 6 months duration. On evaluation, it emerged that she had a mixed connective tissue disorder with a mesangio-proliferative glomerulonephritis. Her Chest radiograph revealed a well defined left mid and lower zone opacity with evidence of a hilar mass on CT Thorax. Histopathological examination following CT guided biopsy of the mass revealed a hyaline vascular type of Castleman's disease. Mixed Connective Tissue Disorder with Castleman's Disease is a rare association; the patient presenting with varied and interesting manifestations. It is important to understand this association in view of management. The exact etio-pathogenesis of the autoimmune manifestations in patients with Castleman's disease is not clear. Treatment with immunosuppression can suppress both immune manifestations and result in tumour regression as well.