A 72-year-old man was referred to hematology after a 1-month history of fatigue and pain in her right hip.
Laboratory tests were performed which included creatinine level of 0.8 mg per decilitre (71 mmol per litre) (normal range, 0.7 to 1.2 mg per decilitre [62 to 106 mmol per liter]), a calcium level of 9.4 mg per decilitre (2.4 mmol per litre) (normal range, 8.8 to 10.6 mg per decilitre [2.2 to 2.6 mmol per litre]), and a total protein level of 9.4 g per decilitre (normal range, 6.6 to 8.3).
He was referred to the hematology service after being monitored for a month and abnormal results on serum protein electrophoresis with immunofixation. The results confirmed a presence of an IgG kappa monoclonal spike of 5.5 g per decilitre. Furthermore, a skeletal survey was performed which revealed cystic lesion in the calvaria, pubis and ilium. Bone marrow biopsy confirmed a 70% involvement of plasma cells with kappa light-chain restriction.
The patient was diagnosed with multiple myeloma. The plasma cells showed cells with morphological features characteristic of signet-ring cells.
Signet-ring cells are commonly found in mucin producing adenocarcinomas, however, the cause of its appearance is not completely understood in myeloma. Studies have shown that the presence of such cells is a result of large cytoplasmic inclusions of defective immunoglobulins that displace the nucleus to the periphery.
Maintenance therapy was planned and treatment with bortezomib, cyclophosphamide, and dexamethasone was initiated.