Gelatinous transformation of the bone marrow: A retrospective monocentric case series of 12 patients

Purpose. - Gelatinous bone marrow transformation is a rare complication of unknown pathogenesis related to several underlying diseases. It is described as a focal loss of hematopoietic cells and a deposition of eosinophilic gelatinous substance rich in hyaluronic acid. We report a retrospective monocentric study followed by a literature review. Methods. - We have identified 12 patients with gelatinous transformation from 1999 to 2014. Clinical, biological and cytological data were collected. Results. - A bone marrow aspirate was performed for mild to severe pancytopenia (50%), less frequently for monocytopenia. Mean haemoglobin was 10.4 g/dL, platelets 126.9 G/L and leucocytes 3.82 G/L. Gelatinous transformation was found in all patients. We have identified three hematologic malignancies, three cancers, three severe infections, two anorexia nervosa and one kidney injury. Ten patients had undernutrition, 9 out of the 12 patients died within a year due to advanced underlying disease and comorbidities. Conclusion. - Gelatinous bone marrow transformation is found in various situations of severe undernutrition including anorexia nervosa, advanced cancers or severe sepsis, especially in HIV infection. The deposition of hyaluronic acid probably reduces haematopoiesis. Due to a complex inflammatory process, it alters the hematopoietic microenvironment and the bone marrow stroma. Severe undernutrition and other mechanisms are reviewed in this study. Gelatinous degeneration is still a rare disorder, indicative of an advanced underlying disease; its recognition could help guide investigations. (C) 2015 Societe Nationale Francaise de Medecine Interne (SNFMI). Published by Elsevier Masson SAS. All rights reserved.