Hyperviscosity syndrome in rheumatoid arthritis with Felty's syndrome: case report and review of the literature.

Hyperviscosity syndrome (HVS) is characterised by high serum viscosity and the involvement of multiple organs, commonly causing retinal haemorrhage, bleeding diathesis, pulmonary hypertension, congestive heart failure (CHF), neurologic deficits and death. It has been reported that HVS is mostly encountered in Waldenström's macroglobulinaemia (80%-90% of all HVS cases) and occasionally in multiple myeloma. HVS in patients with connective tissue diseases (CTD) has rarely been reported. Of 28 cases of HVS reported in patients with CTD, 19 were with seropositive rheumatoid arthritis (RA). However, only six of these 19 cases had Felty's syndrome. Here we report another case of HVS in a patient with RA as well as Felty's syndrome.