Purpose: To assess the classification of Greipp et al in a group of multiple myeloma (MM) patients, in an attempt to correlate the morphological patterns with the clinico-biological features of the disease.
Material and methods: Bone marrow aspirates from 135 patients with multiple myeloma were examined by two different observers.
Results: Full accordance existed in 122 cases (90%). The four morphological MM subgroup distribution was: mature, 38%; intermediate, 30%; immature, 18%, and plasmoblastic, 14%. The analysis of the M component types with regard to morphology showed increased IgA cases within the intermediate (40%) and immature (48%) MM (p = 0.01), and Bence-Jones cases within the plasmoblastic MM (32%). On the contrary, no differences were found with regard to the clinical stage, although none of the plasmoblastic MM was in stage I. The incidence of renal insufficiency and of high bone-marrow infiltration progressively increased from mature to plasmoblastic MM, the difference between the extreme morphological groups being significant. The incidence of hypercalcaemia and lower paraprotein rates was higher in plasmoblastic myeloma, with significant difference with respect to mature myeloma (p = 0.05). The median survival was longer in intermediate (27.8 months) and mature (22.5 months) myelomas than in plasmoblastic (17.9 months) and immature (13.6 months) myelomas. After grouping the mature forms (intermediate plus mature) and the immature ones (plasmoblastic plus immature) the survival differences approached statistical significance (p = 0.07).
Conclusions: This study suggests that the morphological examination of plasma cells should be included in the prognostic criteria of multiple myeloma.