[Recurrent amylase-producing multiple myeloma responding to pomalidomide and carfilzomib-containing therapies]

A 73-year-old woman diagnosed with symptomatic multiple myeloma (MM; IgG-κ type, D&S: IIIA, ISS: 2) was administered bortezomib plus dexamethasone (BD) therapy. Post BD therapy, although autologous hematopoietic stem cell transplantation and thalidomide, lenalidomide, and melphalan/prednisolone/thalidomide (MPT) therapies were also performed, the patient remained unresponsive. However, the disease relapsed, and she eventually developed pantalgia. Therefore, the patient was admitted to our hospital and was administered pomalidomide and dexamethasone (Pd) therapy. The serum amylase (AMY) and urine AMY levels were 6,329 and 6,098 IU/l, respectively, which were salivary gland-type amylase (S-AMY). Notably, the markedly high levels immediately decreased after the first course of the Pd therapy; additionally, the pantalgia also disappeared. The S-AMY level in the supernatant from cultured bone marrow mononuclear cells was higher than that observed in a normal control. In addition, AMY was high when MM previously relapsed, suggesting the presence of AMY-producing MM. Although AMY-producing MM was first reported by Hata et al. in 1988, few cases have been reported in the new-drug era. In conclusion, AMY-producing MM frequently, including in our case (as the patient was refractory to treatment), is difficult to treat. However, our patient positively responded to the novel next-generation drugs such as pomalidomide and carfilzomib.