A variant of gelatinous transformation of marrow in leukemic patients post-chemotherapy.

A variant of gelatinous transformation of marrow was described in leukemic patients post-chemotherapy. This lesion was found in 8 out of 1833 post-chemotherapy bone marrows from 429 patients with leukemia. Histologically, this variant form was identical to the classical gelatinous transformation except for the absence of fat atrophy. In marrow smears, mucoid strands were seen between marrow particles and oriented along the direction of spread. In clot and trephine sections, an eosinophilic ground substance was widespread, filling out spaces around the fat cells, which occupied the normal proportion of marrow space. At high magnification, this ground substance appeared granular and fibrillary, a non-specific feature which could also be seen in fibrin clot commonly found in marrow sections. This eosinophilic ground substance, however, can be distinguished from fibrin clots by positive staining with Alcian Blue (pH 2.3) and inhibition of the staining after treatment with hyaluronidase. Clinically, in contrast to the classical form, this variant form of gelatinous transformation was acute in onset, transient, and associated with chemotherapy but not with cachexia.