MULTIPLE-MYELOMA WITH HAIRY CELL-LIKE FEATURES

Hairy cell leukemia (HCL) and multiple myeloma (MM) are well-described disease entities with characteristic clinical and pathologic features . We describe two patients initially treated for MM in whom atypical c linical and morphologic features subsequently developed that raised th e possibility of HCL. Although the cytologic appearance and immunophen otype were not diagnostic of HCL, these cases challenge the criteria u sed to diagnose MM, HCL, and ether recently described villous neoplasm s.