Acute promyelocytic leukemia with increased bone marrow reticulin fibrosis: Description of three cases and review of the literature.

Pathologic increase in bone marrow reticulin fibrosis can be present in many malignant hematopoietic diseases. In acute leukemia, one-third of patients have some degree of marrow reticulin fibrosis at presentation, which is thought to be related to cytokine release from blasts. Marrow fibrosis is particularly common in acute megakaryoblastic leukemia, while this change is rarely seen in acute promyelocytic leukemia. Six case reports of acute promyelocytic leukemia with marrow reticulin fibrosis have been described so far in the literature. Herein, we present three cases of classical acute promyelocytic leukemia with increased marrow reticulin fibrosis encountered in our institution, summarizing their clinicopathologic features, treatment, and outcome to date. Awareness of the features of acute promyelocytic leukemia with marrow reticulin fibrosis is important as it may guide treatment options.