A 27-year-old Chinese male presented with multiple myeloma. Over his 18-month course he manifested a number of unusual features of his disease including his young age, marked organomegaly, a testicular plasmacytoma, multiple intracranial extraskeletal plasmacytomas and meningeal involvement, and peripheral blood plasmacytosis. The case is described and recent literature on these rare manifestations is reviewed. Am. J. Hematol. 57:51-56, 1998.