P128 | Beyond thresholds: hyperviscosity syndrome in Waldenström’s macroglobulinemia - A Case report

B.A.L. Rocca¹, S. Tunnera², B. Matilde², M.C. Vinci³, M.L. Imbalzano³, V. Vannucchi³, B.M.A. Cimolato³ | ¹AUO Careggi, Firenze, ²AUO Careggi, Firenze, ³Santa Maria Nuova, Firenze, Italy

Premises: Hyperviscosity syndrome (HVS) is marked by abnormal blood flow resulting from disorders in blood cell and plasma components. Most of the serum component abnormalities are caused by plasma cell dyscrasias, among these Waldenstrom’s macroglobulinemia is the most frequent cause of the HSV.
Description of the Case report: A 64-year-old woman, with a one-month history of headaches and blurred vision, presented after transitory loss of consciousness. Blood tests revealed a high lymphocyte count and the presence of two monoclonal components, IgM kappa and IgG Lambda, indicating plasma cell dyscrasias. Although the monoclonal component levels were below the usual threshold for HVS, the clinical presentation and retinal vein dilation with a tortuous ‘sausage link’ appearance and flame haemorrhages observed in the fundus examination, supported the diagnosis. The treatment of the HVS was initiated, and three sessions of plasmapheresis led to a complete regression of symptoms. Immunophenotyping on peripheral blood and bone marrow biopsy confirmed Waldenstrom’s macroglobulinemia. Viscosity tests showed high plasma and whole blood viscosity (14 mPa.s, 72 mPa.s).
Conclusions: Hyperviscosity syndrome can be a life-threatening condition requiring prompt identification and management. This case highlights that, although the likelihood of HVS increases at higher levels of immunoglobulin, there is no discrete cutoff and HVS should be considered for any patients with paraprotein-secreting hematologic malignancy and a characteristic clinical presentation.