Gelatinous transformation of bone marrow

A comprehensive review on gelatinous transformation of the bone marrow

INTRODUCTION

Gelatinous transformation of the bone marrow (GTBM) represents a clinically significant but often underdiagnosed condition, emphasizing the pivotal role of accurate diagnosis in facilitating appropriate treatment strategies.

AREAS COVERED

This special report synthesizes insights gathered from a comprehensive appraisal of clinical and pathology publications on GTBM available on PubMed. By employing search terms such as 'gelatinous,' 'gelatinous transformation,' and 'bone marrow,' this report aims to provide a nuanced understanding of GTBM, elucidating distinctive pathological features while distinguishing it from similar pathologies. The review also discusses currently identified causes of GTBM, clinical, imaging, pathologic and laboratory findings that are associated with GTBM, and treatment options available.

EXPERT OPINION

Contrary to popular belief, we suggest that nutrient deficiency is not solely responsible for the pathogenesis of GTBM and that malignancies, infection, and inflammatory conditions plays a critical role in its pathogenesis. We propose that further research on the pathophysiology of GTBM should be performed to unravel the complex interplay of nutritional and inflammatory factors in hematopoiesis, paving the way for innovative treatment approaches in hematopoietic disorders. To better facilitate further research in GTBM, we suggest formulating a pooled patient database with nutritional, genetic, and cytokine markers in a prospective fashion.

Decreased Volume of Bone Marrow Adipocytes With Sparse Gelatinous Marrow Transformation in a Patient With Pancytopenia With Anorexia Nervosa: A Case Report

Patients with anorexia nervosa (AN) often have complications of hematologic abnormalities and pancytopenia, which can be fatal. In patients with AN, the rates of anemia, leukopenia, and thrombocytopenia have been reported as 16.7-39%, 7.9-39%, and 5-11%, respectively; in patients with severe AN, the rates of anemia, leukopenia, thrombocytopenia, and pancytopenia have been reported as 47-83%, 49.5-79%, 16.8-25%, and 16.4-23%, respectively. Hematologic abnormalities are often associated with morphological myeloid transformations such as hypoplasia, aplasia, and gelatinous marrow transformation (GMT). Hypocellularity, such as hypoplastic or aplastic, often results in a dry tap, whereas GMT does not usually result in this because of the aspiration of gelatinous material. Therefore, bone marrow aspiration in patients with pancytopenia with AN usually does not show a dry tap. The bone marrow adipocyte (BMA) volume increases in patients with AN, except in those with severe malnutrition. Patients with AN experiencing pancytopenia often exhibit GMT associated with atrophy of the originally increased volume of BMAs. Herein, we report the case of a patient with pancytopenia with AN who exhibited a dry tap on bone marrow aspiration. A bone marrow biopsy revealed sparse GMT with decreased BMA volume and areas of hematopoietic cells, adipocytes, and no GMT. A 13-year-old Japanese girl weighing 25.8 kg (BMI: 10.0 kg/m2) was admitted to our hospital and received nutritional therapy. The patient presented with pancytopenia and fever, prompting the conduct of bone marrow examinations. Bone marrow aspiration resulted in a dry tap, and the bone marrow biopsy revealed sparse GMT with a decreased volume of BMAs. Additionally, an area devoid of hematopoietic cells, adipocytes, or GMT was observed. Nutritional therapy resulted in weight gain and improved pancytopenia. Upon discharge, the patient weighed 40.0 kg (BMI: 15.5 kg/m2) with a normal WBC count, hemoglobin levels, and platelet count. It is significant to study hematological and bone marrow changes because patients with AN often present with hematologic abnormalities. The identification of sparse GMT, which is associated with a decrease in BMA volume and the presence of an area devoid of hematopoietic cells, adipocytes, or GMTs, is a novel finding. The improvement in pancytopenia following nutritional therapy suggests a link between myeloid transformation and malnutrition. Consequently, in patients with pancytopenia associated with AN exhibiting these bone marrow findings, nutritional therapy is necessary.

Gelatinous Transformation of Bone Marrow Following Lymphoma and a Novel, Potential Treatment

Gelatinous transformation of bone marrow (GTBM) is a rare hematologic condition in which hematopoietic cells in the bone marrow are replaced by extracellular gelatinous substances, often resulting in cytopenias. The true incidence of this condition is presently unknown, as the current body of literature primarily consists of case reports. However, an analysis of a large bone marrow registry suggests that this is a highly rare entity even among a population requiring bone marrow biopsy. We present a case of a 24-year-old man with a history of diffuse large B cell lymphoma and an associated 45-kilogram weight loss, who was later found to have GTBM. The extent of his cytopenias resulted in a prolonged hospitalization with numerous complications, eventually leading to experimental treatment with allogeneic stem cell transplantation (ASCT). To our knowledge, this is the first reported case of GTBM in which ASCT was employed as a potential treatment modality. While our patient did have clinical improvement following ASCT, the permanence of these results is presently unclear. Furthermore, it is uncertain if the ASCT was truly causative of the stabilization of the patient. Given this, we are currently unable to advocate for ASCT as a treatment for GTBM. We report this case to raise awareness of this rare entity in the context of refractory cytopenias.

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.

Severe neutropenia in an anorexic adolescent girl: a stigma of underfeeding syndrome?

PURPOSE

We describe a case of severe, prolonged neutropenia in an adolescent girl hospitalized for anorexia nervosa (AN) which occurred during a refeeding procedure in the absence of refeeding syndrome.

METHODS

This case report includes retrospective anamnestic, clinical and biological data from the patient's medical record. A literature review was conducted on the haematological changes described in the undernutrition and refeeding periods, and also on recent data for underfeeding syndrome in patients with anorexia nervosa.

CONCLUSION

Leuconeutropenia is an adaptive condition observed in undernutrition in AN, usually rapidly and completely reversible in the course of refeeding and weight gain. We describe a rare case of severe, prolonged neutropenia despite appropriate care in the absence of refeeding syndrome and without gelatinous bone marrow transformation. We suggest that neutropenia in adolescent anorexia nervosa could be a stigma of underfeeding syndrome resulting from an overly cautious refeeding strategy.

LEVEL OF EVIDENCE

Level V, descriptive study.

Signet-ring cell appearance of atrophic fat cells

Cells with 'signet-ring' appearance were found at post-mortem examination of a man with a history of chronic illness, weight loss and multiple regions of 'bowel thickening' during life. Due to the decedent's history, the finding raised the possibility of disseminated signet-ring adenocarcinoma. However, the vacuoles did not stain for mucin and the cells did not stain for keratin. The cells did stain for calretinin and so a diagnosis of signet ring mesothelioma was considered. However, it was suggested that the cells with a cytoplasmic vacuole displacing the nucleus to one side producing the signet-ring appearance were instead atrophic fat cells. This was subsequently proven by Oil Red O staining.

Anorexia Nervosa and the Immune System-A Narrative Review

The pathogenesis of an increasing number of chronic diseases is being attributed to effects of the immune system. However, its role in the development and maintenance of anorexia nervosa is seemingly under-appreciated. Yet, in examining the available research on the immune system and genetic studies in anorexia nervosa, one becomes increasingly suspicious of the immune system’s potential role in the pathophysiology of anorexia nervosa. Specifically, research is suggestive of increased levels of various pro-inflammatory cytokines as well as the spontaneous production of tumor necrosis factor in anorexia nervosa; genetic studies further support a dysregulated immune system in this disorder. Potential contributors to this dysregulated immune system are discussed including increased oxidative stress, chronic physiological/psychological stress, changes in the intestinal microbiota, and an abnormal bone marrow microenvironment, all of which are present in anorexia nervosa.

Terminologia Histologica 10 years on: some disputable terms in need of discussion and recent developments

At first sight, the issue of morphological terminology may seem to be a "closed and unchanging chapter", as many of the structures within the human body have been known for decades or even centuries. However, the exact opposite is true. The initial knowledge of the microscopic structure of the human body has been continuously broadening thanks to the development of new specialized staining techniques, discovery of the electron microscope, or later application of histochemical and immunohistochemical methods into routine tissue examination. Contrary to popular belief, histology has a status of constantly developing scientific discipline, with continuous influx of new knowledge, resulting in an unavoidable necessity to revise the histological nomenclature at regular intervals. The team of experts of the Federative International Programme on Anatomical Terminology, a working group of the International Federation of Associations of Anatomists, published in 2008 the First Edition of Terminologia Histologica. Terminologia Histologica (TH) is the best and most extensive of all the histological nomenclatures ever issued. However, here we suggest that several terms of important histological structures are still missing while several other terms are disputable. First, we present some clinically important terms of cells and tissue structures for inclusion in the next TH and, in a second part, we refer to some new terms in the current edition of the TH which are not yet mentioned in current histology textbooks (e.g., fusocellular connective tissue, bundle bone as the third type of bone tissue, spongy layer of vagina or arteria vaginata from the splenic white pulp). With this article we hope to start a wide scientific discussion which will lead to an inambiguous definition and demonstration of typical examples of all terms in the TH, with the result that the new edition of the Terminologia Histologica will become an internationally accepted communication tool for all practitioners and teachers of histology alike.

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.