Three cases of synchronous solid tumor and multiple myeloma.

The association between a multiple myeloma and a secondary solid tumor is not well established. Some reports showed an increased risk of secondary solid neoplasms in multiple myeloma patients, but others have not. Three cases of the synchronous occurrence of multiple myelomas and solid tumors, namely, a small cell carcinoma of the lung, an adenocarcinoma of the colon and a squamous carcinoma of the pyriform sinus were experienced at our hospital. Therefore, herein is reported the clinical courses and treatment results. The stage of multiple myeloma was Durie-Salmon stage I in all of three cases; therefore, the solid tumors were treated as a primary target because the prognosis of early stage multiple myeloma is generally better than that of advanced solid tumor, while a smoldering or stage I myeloma do not need primary therapy until progression of the multiple myeloma. Two patients died of their solid tumors, but one patient is alive.