Resolution of gelatinous bone marrow transformation following hormone replacement therapy in a patient with primary insufficiency of the adrenal and thyroid glands

Gelatinous transformation of bone marrow in a rabbit

A 9-y-old, spayed female rabbit was presented for evaluation of hypoglycemia and lateral recumbency. The patient was hypothermic and had diffuse muscle wasting; weight loss since a previous visit was also noted. Hematologic abnormalities included progressive nonregenerative anemia and severe heteropenia. Evaluation of a bone marrow aspirate sample revealed active hematopoiesis with abundant pink matrix. The matrix material stained positively with periodic acid-Schiff and alcian blue, and a diagnosis of gelatinous transformation of the bone marrow (GTBM, serous atrophy of fat) was made. Although its precise prevalence remains to be determined, GTBM should be suspected in rabbits with persistent cytopenias following prolonged starvation or gastrointestinal disease.

Autopsy of a case of rheumatoid arthritis with severe bicytopoenia due to gelatinous transformation of the bone marrow

We present the case of an elderly female patient with rheumatoid arthritis (RA) treated with methotrexate. She was referred to our hospital with severe malaise. She was emaciated and had massive pleural effusion that induced atelectasis. Her blood tests revealed elevated CRP, leukopenia, and severe anaemia. She lost consciousness on the third day of hospital stay and passed away the following day. Her autopsy showed gelatinous transformation of the bone marrow that gave rise to bicytopoenia, whereas there were no other causes for severe anaemia. Bone marrow gelatinous transformation can cause impaired haematopoiesis in elderly RA 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.

[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.