Recurrence of Waldenström macroglobulinemia accompanied by factor X deficiency

A medical check-up revealed severe anemia in an 85-year-old man who had been diagnosed with Waldenstrom macroglobulinemia 11 years previously. On the other hand, prolonged PT and aPTT were demonstrated on admission, and were attributed to a significant decrease in factor X activity. These abnormalities were all considered to be have been caused by an exacerbation of the underlying disease and, thus, chemotherapy with the RCD regimen (rituximab, cyclophosphamide, dexamethasone) was started. No significant improvement was obtained and the patient died suddenly on day 154. AL amyloidosis was diagnosed by histopathological examinations and also confirmed by a sequence analysis of amyloid protein. This case with Waldenstrom macroglobulinemia complicated by AL amyloidosis and recurrent factor X deficiency is quite rare.