[1374] A Retrospective Study of Correlation of Morphological Patterns, MIB1 Proliferation Index and Survival Analysis in 134 Cases of Plasmacytoma

Kiran Ghodke, Sumeet Gujral. Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India

Background: There is a need for features that indicate likelihood of “myeloma” in patients with plasmacytoma without other manifestations. This study was an attempt to study morphology and MIB1 in plasmcytoma to achieve above.
Design: All plasmacytomas from 2002 to 2009 were reviewed and out of total 134 cases including – 88 solitary plasmacytoma of bone (SP) and 46 extramedullary plasmacytoma (EMP) were asssesed. Tumors were graded as per Bartl's histological grading system.
Results: Of the 134 cases commonest site was vertebral body in SP (36%) and upperaerodigestive tract in EMP (48%).On serum electrophoresis, overall M band was detected in 41% cases, Bence- Jones proteins in 11%, while remaining cases did not have paraproteinemia. Both SP and EMP showed similar morphological features viz. Sheet like arrangement (82%), followed by nests (5.5%).The MIB1 proliferation index ranged from less than 1% to 80% of tumor cells and was slightly higher in EMP as compared to SP (p value-0.002).MIB1 proliferation index was signficantly associated with grade of tumor (p= 0.002), higher β2 microglobulin levels, aggressive course, high rate of recurrence and progression to multiple myeloma (MM). Ninety percent cases of plasmacytoma which progressed to MM showed MIB1 labeling index <30%, however it was not statistically significant in predicting the disease progression. Only a single case out of 10 cases with progression harboured t(11,14) translocation on cytogenetic studies. With the median follow of 19 months (range: 1-99 months), 10 SP progressed to myeloma in 7 patients while 3 developed EMP, with a median interval of 21 months (range: 8 - 75 months) for the development of MM and 3 months (range: 3 - 9 months) for the progression to EMP. One patient died soon after finishing palliative radiotherapy while seven died due to therapy related side effects.Five-year survival for EMP varied by site, with plasmacytoma of the brain/CNS having the poorest survival as compared to plasmacytoma at other sites, including lymph node which had the best survival.
Conclusions: Grade and MIB1 index help in predicting aggressive course in plasmacytomas and should be used in the routine evaluation and management of plasmacytomas.
Category: Hematopathology

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 220, Wednesday Afternoon


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