Concurrent appearance of multiple myeloma with other B-cell lymphoid neoplasms. A report of two cases.

Two cases of multiple myeloma appeared concurrently with other B-cell neoplasms. These were rare occurrences; only one case of concurrent lymphoma and myeloma and 11 cases of concurrent chronic lymphocytic leukemia and myeloma have been reported in the literature. It was unclear in each case if the B-cell neoplasm arose from a common cell at different phases of development. The rarity of reports in the literature suggests that this combination of the two diseases is accidental.