PMC3026984_01
(a, b, c) relatively hypercellular marrow with marked fibrosis, abundant atypical megakaryocytes, and scattered immature-appearing cells, (a, b) H&E-stained sections, (c) reticulin stain). (d, e, f) following treatment with lenalidomide, the bone marrow showed patchy hematopoiesis with areas of high and low cellularity ((d) H&E-stained section), decreased numbers of megakaryocytes ((e) H&E-stained section) and a marked reduction in reticulin fibrosis ((f) reticulin stain).
CRIM2010-421239.001.jpg
PMC3026984_01_CRIM2010-421239.001.jpg
fig1
Bone marrow aspiration did not yield any material, and it was considered as "dry tap." Pathology revealed increased cellularity and fibrosis; there was prominent hyperplasia of the megakaryocytic lineage with clustering and dysplastic features (Figures 1(a) to 1(c)). A repeat bone marrow was performed at the 18th cycle of lenalidomide which for the first time showed a patchy distribution of cellularity; however, in areas of high cellularity, an identical clustering of the abnormal megakaryocytes could be observed (Figures 1(c) to 1(d)).