Smouldering Myeloma: Chasing a Hyperviscous Sample

Serum hyperviscosity is a rare laboratory finding. Amongst several causes of serum hyperviscosity, malignant disorders are quite common. Monoclonal gammopathy is a family of disorders in which monoclonal gammopathy of unknown significance (MGUS) and smoldering myeloma are the asymptomatic variants whereas multiple myeloma is the malignant variant showing different signs and symptoms related to bone lesions, renal failure and anemia. Initially during sample preparation, pipetting of a serum sample was found to be cumbersome. This sample during routine analysis in the automated analyser flagged repeated alarms for clot detection indicating a possibility of a hyper viscous sample. Serum was subjected to fibrinogen and D- dimer test. The D-Dimer levels were found to be normal and fibrinogen levels were mildly elevated. Routine biochemistry investigations were normal except grossly reversed A/G ratio. Due to gross reversal of A/G ratio, the possibility of Multiple myeloma was entertained. Physician's were alerted on telephone. Serum was sent for electrophoresis which showeda M spike. Bone marrow aspirate showed 13% plasma cells. Considering the above lab results the diagnosis of monoclonal gammopathy of smoldering type was considered. The sample was traced to a 77 years old male, who presented to Medicine OPD with the chief complaints of generalised weakness for two months without any history of fever. On physical examination pallor was evident but there was no icterus, cyanosis, clubbing, lymphadenopathy or edema. On haematological evaluation patient was found to be anemic. Careful tracking of hyperviscous patient's serum followed up by thorough investigation led us to the final conclusion that the case mentioned is a rare case of Smoldering type of multiple myeloma.