Paratracheal extramedullary hematopoiesis

Extramedullary hematopoiesis (EMH) is a rare finding in hematology. A 73-year-old female patient with a 1-week history of severe progressive dyspnea was examined, and computed tomography (CT) showed a paratracheal mass 3 cm in size located 1 cm below the vocals cords and causing obliteration of the tracheal airway. Cytology of a needle biopsy revealed EMH. External radiotherapy of 200-cGy fractions to a total dose of 2000 cGy was administered with 3-dimensional conformal planning to treat the progressive symptoms. The patient's clinical symptoms started to improve 2 days after radiotherapy and had completely disappeared after 7 days. CT scans showed complete response on follow-up at 1 week to 5 months after radiotherapy. Mature and immature hematopoietic cells and many adipose cells were seen in the pretreatment samples. Histologic findings in the posttreatment samples showed that these cells had completely disappeared due to the conformal radiotherapy. On the basis of clinical, radiologic, and histologic results, we suggest that conformal radiotherapy may be useful for the treatment of paratracheal localization of EMH because good tumoral irradiation was obtained in this case, with the protection of normal tissues.     

Pulmonary extramedullary hematopoiesis

Extramedullary hematopoiesis (EMH) is the formation and development of blood cells outside of the bone marrow. Of particular interest to chest physicians and radiologists is the occurrence of EMH in the lungs and pleura. There have been several reports of patients presenting with pulmonary EMH published in the literature and the majority are due to a secondary process, such as myeloproliferative disorders, hemolytic anemias, hereditary spherocytosis, and Gaucher disease. We present a case report of pulmonary EMH and a review of the literature concentrating on the etiology, clinical presentation, pathophysiology, diagnosis, and therapy for this uncommon disorder.     

Pleural extramedullary hematopoiesis

INTRODUCTION: Agnogenic myeloid metaplasia, associated with myelofibrosis, is a myeloproliferative disorder. Extramedullary hematopoiesis in the pleura is rare and its prognosis is often severe. EXEGESIS: Herein we report a 64-year-old woman, who presented with pleural extramedullary hematopoiesis, treated by hydroxyurea-based chemotherapy with disease control. CONCLUSION: Clinical, histological, therapeutic and evolutive aspects of this uncommon entity will be reviewed.     

Thoracic extramedullary hematopoiesis associated with hereditary spherocytosis.

A 54-year-old man was diagnosed with hereditary spherocytosis. An X-ray of the chest disclosed bilateral round masses in the upper and lower posterior mediastinum. CT showed homogeneous round masses of soft tissue density in the posterior mediastinum. A needle biopsy of the mass showed hyperplastic erythroid bone marrow. Fatty metamorphosis of the masses was observed in CT 2 years after splenectomy but showed no change in size.     

Ascites and pleural effusion secondary to extramedullary hematopoiesis.

Extramedullary hematopoiesis in the pleura and peritoneum is rare. It is usually asymptomatic and generally is diagnosed on post mortem examination. Herein we describe a 33-year-old woman with long-standing myelofibrosis who presented with symptomatic ascites and pleural effusion. After complete evaluation, these were found to have been caused by extramedullary hematopoietic implants to the pleura and peritoneum. The pleural effusion responded to low-dose radiotherapy.     

Chronic allergen challenge induces pulmonary extramedullary hematopoiesis

Allergic inflammation is associated with increased generation and trafficking of inflammatory cells, especially eosinophils, to sites of inflammation. The effect of acute versus chronic airway allergen challenge on hematopoietic activity in the bone marrow (BM) and lungs was investigated using murine models of allergic airway inflammation. Acute allergen challenge induced proliferation of BM cells and significantly increased generation of eosinophil, but not multipotent, granulocyte-macrophage (GM), or B-lymphocyte progenitor cells. However, no hematopoietic activity was observed in the lungs. With chronic challenge, BM cells failed to proliferate, but exhibited increased capacity to generate multipotent as well as eosinophil, GM, and B-lymphocyte progenitors. In addition, increased generation of eosinophil- and GM-specific progenitors was observed in the lungs. Although no differences were observed in their ability to roll on BM endothelium in vitro or in vivo, CD34-enriched hematopoietic/stem progenitor cells (HSPCs) from chronic-, but not acute-, challenged mice demonstrated reduced migration across BM endothelial cells associated with decreased CXCR4 expression. Overall, these studies demonstrate that chronic allergen exposure can alter BM homing due to decreased transendothelial migration enabling noninteracting HSPCs to egress out of the BM and recruit to sites of inflammation such as the airways, resulting in extramedullary hematopoiesis.     

Sickle cell anemia and epidural extramedullary hematopoiesis

Acute flaccid paralysis due to epidural extramedullary hematopoiesis developed in a 43-year-old man with sickle cell anemia. The patient showed no response to emergency decompressive laminectomy, radiotherapy, or exchange transfusion, and his neurologic deficit persisted unimproved. This is the first reported case of acute or irreversible spinal cord compression due to epidural extramedullary hematopoiesis in a patient with sickle cell anemia.     

Lymphographic appearance of nodal extramedullary hematopoiesis simulating lymphoma

A 63 year old man underwent lymphography because of anemia, splenomegaly, and fever. Nodes in the high para-aortic region had the appearance of involvement with malignant lymphoma. Subsequent biopsy showed that these changes were due to the partial replacement of nodal tissue with extramedullary hematopoiesis.     

Cutaneous extramedullary hematopoiesis following splenectomy for idiopathic myelofibrosis

A 50-year-old man with idiopathic myelofibrosis had development of extensive cutaneous extramedullary hematopoiesis after undergoing splenectomy. Treatment with hydroxyurea was not effective, but electron-beam irradiation controlled the cutaneous infiltration. This rare clinical manifestation of idiopathic myelofibrosis can be confused with cellulitis, and diagnosis depends upon biopsy.     

Chronic marrow failure,myelosclerosis and extramedullary hematopoiesis

Thirty cases, including 20 autopsied, of chronic bone marrow failure, myelosclerosis and osteosclerosis have been presented and compared with similar reportsin the literature. The bone marrow histopathologic sequence observed involvedrepeated necrobiosis of maturing hematopoietic cells, followed by overgrowth ofmarrow reticulum and frequent ossification. Immature erythrocytes and leukocyteswere often found in the circulation, and extrameduallary hematopoiesis was characteristic. One case was complicated by leukemia. Etiologic factors implicatedincluded exogenous toxic chemicals, liver dysfunction, endocrine abnormalities,blood loss or destruction and cardiovascular disease. Suspicion was directed towardthe pathogenetic importance of protracted bone marrow exposure to certain substances normally conjugated rapidly in the liver and excreted.

Note: ACKNOWLEDGMENTThe authors acknowledge gratefully the continued assistance of Dr. John Norcross and Dr. DonatP. Cyr of Lahey Clinic, Boston, who permitted use of material from living cases.We are indebted to Dr. Shields Warren, New England Deaconess Hospital, Boston, for permissionto review 10 cases; to Dr. Olive Gates, Harvard Medical School, for advice and assistance with 7 cases,including material from the Collis P. Huntington Hospital; to Professor William Boyd for 5 cases fromBanting Institute, Toronto; to Dr. Paul D. Rosahn, New Britain General Hospital, New Britain, Conn.,and Dr. William Dameshek for one case; to Dr. A. J. Blanchard for several cases from Christie St. Hospital, Toronto; to Drs. Lorne Whittaker and Sabin of St. Catherine’s Hospital for one case; and to Dr.John Brownlee for hematologic studies from one case.

     

遗传性球形红细胞增多症并发纵隔脊柱旁髓外造血1例

髓外造血(EMH)是指在骨髓以外的部位出现造血组织,是骨髓功能异常的代偿机制。本文报道1例遗传性球形红细胞增多症(HS)并发胸椎旁EMH患者,并结合文献报道进行分析。1病历资料患者女,52岁。因受凉后发热,心悸,尿黄于2009-