[Gelatinous transformation of the bone marrow and acute hepatitis in a woman suffering from anorexia nervosa]

Gelatinous Transformation of Bone Marrow in a Patient with Anorexia Nervosa: An Uncommon but Reversible Etiology

BACKGROUND Anorexia nervosa is a relatively frequently encountered eating disorder. Beyond its psychiatric significance, it is associated with multiple hematological features such as cytopenia. It can be related to gelatinous transformation of the bone marrow. CASE REPORT We describe the case of a 20-year-old male admitted for rapid involuntarily weight loss. He presented with extreme bradycardia with a heart rate of 30 beats per minute with recent psychomotor impairment. Routine laboratory tests showed pancytopenia, and cytolysis on liver function tests. Cardiac investigations did not reveal abnormalities except for sinus bradycardia. Bone marrow aspirate revealed hypo-cellular marrow with infiltration by gelatinous substance. In addition, bone marrow biopsy showed fat cell atrophy along with loss of hematopoietic elements in areas of gelatinous transformation. During the patient's hospital stay, he had a restrictive oral diet. Thus, after consulting with a psychiatric specialist, a diagnosis of anorexia nervosa complicated with gelatinous transformation of bone marrow, bradycardia, and acute hepatitis was made. After psychiatric treatment and nutritional care, the patient regained weight, had a normal heart rate and normal liver function tests, and his full blood count and bone marrow examination were within normal range. CONCLUSIONS Gelatinous transformation of bone marrow can be the revealing feature of anorexia nervosa and some potentially reversible associations might prove life threatening if misdiagnosed. Furthermore, lack of suspicion can lead to unwarranted investigations increasing the cost incurred in healthcare delivery. Our patient had 3 systems involved: cardiac, hepatic, and hematological systems. Gelatinous transformation of bone marrow, although a rare condition, must be considered in such patients.

Gelatinous transformation of bone marrow: rare or underdiagnosed?

Gelatinous transformation of the bone marrow (GTBM) is a rare hematologic entity, which was first described by Paul Michael in 1930. GTBM is mostly associated with caloric intake/anorexia nervosa, although it also has been described accompanying other pathologic conditions, such as malignancy, systemic lupus erythematosus, HIV infections. Even though the diagnostic features of the hematopoietic tissue, such as hypoplasia, adipose cell atrophy, and deposition of a gelatinous substance in the bone marrow (which stains with Alcian blue at pH 2.5) are quite specific, the underlying pathogenic mechanisms remain poorly understood. Considering the evidence of reversibility—notably in cases of malnutrition and anorexia—this entity should be kept high on cards as a possible differential diagnosis of patients presenting with cytopenias and associated weight loss or starvation, especially in developing countries with nutritionally deprived populations. On an extensive review of the literature aimed at comprehensively addressing the evolution of the GTBM from the past century until now, we conclude that the lack of clinical suspicion and awareness regarding this pathologic entity has led to misdiagnosis and delayed diagnosis.

Increased Bone Marrow Adiposity in a Context of Energy Deficit: The Tip of the Iceberg?

Elevated bone marrow adiposity (BMA) is defined as an increase in the proportion of the bone marrow (BM) cavity volume occupied by adipocytes. This can be caused by an increase in the size and/or number of adipocytes. BMA increases with age in a bone-site-specific manner. This increase may be linked to certain pathophysiological situations. Osteoporosis or compromised bone quality is frequently associated with high BMA. The involvement of BM adipocytes in bone loss may be due to commitment of mesenchymal stem cells to the adipogenic pathway rather than the osteogenic pathway. However, adipocytes may also act on their microenvironment by secreting factors with harmful effects for the bone health. Here, we review evidence that in a context of energy deficit (such as anorexia nervosa (AN) and restriction rodent models) bone alterations can occur in the absence of an increase in BMA. In severe cases, bone alterations are even associated with gelatinous BM transformation. The relationship between BMA and energy deficit and the potential regulators of this adiposity in this context are also discussed. On the basis of clinical studies and preliminary results on animal model, we propose that competition between differentiation into osteoblasts and differentiation into adipocytes might trigger bone loss at least in moderate-to-severe AN and in some calorie restriction models. Finally, some of the main questions resulting from this hypothesis are discussed.

[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 10.4g/dL, platelets 126.9G/L and leucocytes 3.82G/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.

[Extensive bone marrow necrosis with sepsis in primary thrombocytemia: a case report and literature review]

INTRODUCTION

Bone marrow necrosis is a very rare condition which is characterized by a necrosis of hematopoietic progenitors, adipocytes and reticulin network.

CASE REPORT

We report a 62-year-old woman admitted to an intensive care unit for an essential thrombocytemia associated with bone marrow necrosis complicated by septic shock and progressive multi-organ failure. To our knowledge, this is the second case reported in the literature. The clinical presentation of bone marrow necrosis includes non-specific symptoms such as fever, bone pain and sometimes a clinically significant medullar insufficiency syndrome. Biology can reveal cytopenias, elevated LDH and alkaline phosphatase serum levels. The diagnosis is confirmed by bone marrow trephine biopsy. Bone marrow necrosis is classified as extensive if more than 50% of the bone marrow biopsy show necrosis. Haematological malignancies (particularly leukaemia), and solid malignant tumours (particularly gastro-intestinal or lung cancers) represent up to 90% of aetiologies and must be actively researched. Also, sickle cell disease and catastrophic anti-phospholipid syndrome must also be investigated. Essential thrombocytemia remains an exceptional cause of bone marrow necrosis.

CONCLUSION

Overall the prognosis of bone marrow necrosis is poor unless appropriate and intensive treatment, especially for sickle cell disease in which complete medullar regeneration has been observed.