Amylase-producing multiple myeloma.

We managed a case of amylase-producing multiple myeloma with extensive extramedullary spread. We reviewed five cases of amylase-producing multiple myeloma, including this case. This type of multiple myeloma has shown unique clinicopathologic features. (1) A distinct elevation of the serum amylase activity was demonstrated in all five patients. The amylase isozyme was of the S type without exception. (2) Extensive extramedullary spread with extramedullary tumors and/or myelomatous pleural effusions or ascites was seen in all five patients during the course of illness. (3) In three of four cases in which it was mentioned, extensive destruction of multiple bones was demonstrated roentgenographically. (4) In four patients, excepting one with a solitary bone lesion, the survival from the initial therapy was shorter than 1 year. (5) Myeloma cell lines were established in three cases. A common feature of these three cell lines was a translocation of chromosome 1, which supplied the amylase gene. This finding may be pathogenetically related to this entity.