The mechanisms responsible for the initial deposit of monosodium urate (MSU) crystals in gouty joints remain obscure. We report on nine small fragments of tissue that showed an arranged deposit MSU crystals, which were obtained along with synovial fluid (SF) from asymptomatic gouty joints. Three of the fragments had chondrocytic islands, indicating their cartilaginous nature; MSU crystals were found in their depth, all oriented in the same direction and in two of them, a parallel fibrillar appearance of its matrix was apparent following the MSU crystals in the same direction as the fibres (fig 1A). Bundles of undulating parallel fibres—probably of cartilage collagen—detached from two of these fragments. The remaining fragments were composed by similar bundles of undulating parallel fibres without a cellular component, and may constitute remanents of fibrillating cartilage. In four of these fragments, individual crystals were deposited densely packed in transverse rows, following the undulations of the fibres, and always positioned alongside them (fig 1B). Finally, in two additional fragments fewer crystals were seen, always laying parallel to …