[1414] Myelodysplastic Syndrome (MDS) with Elevated Bone Marrow Hematogones: Clinicopathologic Analysis of 8 Cases and Comparison to MDS with Low Hematogones

JM Peters, R Garcia, AC Seegmiller, M Vusirikala, W Chen. University of Texas Southwestern Medical Center, Dallas, TX

Background: Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders characterized by ineffective hematopoiesis resulting in cytopenias. Our previous studies have demonstrated that bone marrow (BM) hematogones (HG) are typically decreased to absent in MDS (AJCP 129:300). However, rare cases of MDS with elevated HG are seen. Our aim was to determine the prevalence and clinicopathologic features of this subtype, and compare to MDS with low HG.
Design: An institutional database was searched for cases of MDS with cytogenetic and 3- or 4-color flow cytometric (FC) analyses from 2001-2009. This yielded 151 MDS cases, of which, 5 cases (3.3%) had a BM HG >1% of total events by FC. An additional 3 referred MDS cases with HG >1% were included in the analyses. Comparisons were between cases of MDS with and without HG >1% within this dataset.
Results: There were 6 females and 2 males, aged 32-82 years. All patients had variable cytopenias with multilineage dysplasia. BM HG was increased with a mean of 4.2% (median 1.9). Cytogenetic analyses showed clonal abnormalities in 5 of 7 analyzed cases, stratified as good cytognetics in 1, intermediate in 2 and poor in 2. These cases were classified as low to intermediate grade MDS in 3 cases, refractory anemia with excess blasts (RAEB) in 3, MDS-therapy related in 2. While MDS with elevated HG was similar to MDS with low HG in most ways, such as encompassing heterogeneous MDS subtypes and a range of cytogenetic abnormalities, this subtype affected younger patients with female predominance.

Comparison of MDS with High and Low BM HG

	sex	age (mean, median, range)	HG% (mean, median, range)
HG>1% (n=8)	2M, 6F	55.8, 57, 32-82	4.2, 1.9, 1.02-13
HG<1% (n=146)	96M, 50F	67.5, 70, 20-87	0.052, 0.0004, 0-0.75
p-value	0.045#	0.01*	<0.001*

* t-test; # Chi-square test


Conclusions: This study confirms our previous observation that low to absent BM HG in a vast majority of MDS. Recognition of this rare variant MDS with elevated HG (comprising 3.3% of entire MDS) is important to avoid misdiagnosis. While MDS with elevated HG is similar to MDS with low HG in many ways, this subtype affects younger patients with female predominance. The biologic significance of this elevated HG remains to be determined.
Category: Hematopathology

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 182, Tuesday Afternoon