Abstract
Aggressive multiple myeloma is a clinicopathologic variant of multiple myeloma characterized by cellular atypia or anaplasia, extramedullary extension, and an aggressive clinical course.
We have studied one such autopsy case showing extensive cutaneous, pulmonary, intraabdominal and retroperitoneal tumor masses at interval of 27 months following disease onset. The development of extensive soft tissue involvement was suspected by abnormal accumulation of Ga-67 citrate and confirmed at autopsy. Most of tumor cells in the extramedullary sites as well as in the bone marrow showed marked morphologic atypia, although plasmacytoid differentiation was evident. However, the bone marrow was not so heavily infiltrated with anaplastic myeloma cells. Biopsy specimens from a cervical lymph node were examined by using immunofluorescent technique. Cytoplasmic IgA, corresponding to the class of serum M-component, was not or faintly detected in the anaplastic cells. There was less increase in serum levels of monoclonal IgA than might be expected from an extensive growth of extraosseous lesions. The patients died three months after the onset of aggressive phase.
The recognition of aggressive myeloma is important for a better understanding of the nature of multiple myeoma. The development of soft tissue and visceral masses is unusual in patients with multiple myeloma. The appearance of these masses can be an ominous sign. As a rule, they do not disappear following irradiation or chemotherapy. In addition, reduction in the level of M-component does not necessarily imply well-controlled disease.
