Extramedullary hematopoiesis manifesting as a symptomatic pleural effusion

Extramedullary hematopoiesis in myeloproliferative neoplasms: Pathophysiology and treatment strategies

Extramedullary hematopoiesis (EMH) is often a physiologic response to ineffective marrow production of hematologic cells. While this can be found incidentally in various physiologic and pathophysiologic states, the myeloproliferative neoplasms (MPNs) are some of the most common underlying conditions found in patients with EMH. Although this process can assist with hematologic production in defective states, the burden of EMH can lead to symptomatic discomfort and mechanical obstructive complications, most commonly in the spleen and liver. Here we describe the pathophysiology of EMH, treatment options, including medical, surgical and radiation-based approaches.

Stapled EGFR peptide reduces inflammatory breast cancer and inhibits additional HER-driven models of cancer

Background

The human epidermal growth factor receptor (HER) family of transmembrane tyrosine kinases is overexpressed and correlates with poor prognosis and decreased survival in many cancers. The receptor family has been therapeutically targeted, yet tyrosine kinase inhibitors (TKIs) do not inhibit kinase-independent functions and antibody-based targeting does not affect internalized receptors. We have previously demonstrated that a peptide mimicking the internal juxtamembrane domain of HER1 (EGFR; EJ1) promotes the formation of non-functional HER dimers that inhibit kinase-dependent and kinase-independent functions of HER1 (ERBB1/EGFR), HER2 (ERBB2) and HER3 (ERBB3). Despite inducing rapid HER-dependent cell death in vitro, EJ1 peptides are rapidly cleared in vivo, limiting their efficacy.

Method

To stabilize EJ1 activity, hydrocarbon staples (SAH) were added to the active peptide (SAH-EJ1), resulting in a 7.2-fold increase in efficacy and decreased in vivo clearance. Viability assays were performed across HER1 and HER2 expressing cell lines, therapeutic-resistant breast cancer cells, clinically relevant HER1-mutated lung cancer cells, and patient-derived glioblastoma cells, in all cases demonstrating improved efficacy over standard of care pan-HER therapeutics. Tumor burden studies were also performed in lung, glioblastoma, and inflammatory breast cancer mouse models, evaluating tumor growth and overall survival.

Results

When injected into mouse models of basal-like and inflammatory breast cancers, EGFRvIII-driven glioblastoma, and lung adenocarcinoma with Erlotinib resistance, tumor growth is inhibited and overall survival is extended. Studies evaluating the toxicity of SAH-EJ1 also demonstrate a broad therapeutic window.

Conclusions

Taken together, these data indicate that SAH-EJ1 may be an effective therapeutic for HER-driven cancers with the potential to eliminate triple negative inflammatory breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1939-7) contains supplementary material, which is available to authorized users.

A 54-year-old Woman with Myelofibrosis and Massive Hemothorax Due to Primary Extramedullary Hematopoiesis of the Pleura

Extramedullary hematopoiesis, which represents ectopic blood cell production, is usually an incidental finding accompanying hematologic pathology. The liver and spleen are the most common sites of extramedullary hematopoiesis, but thoracic involvement is likewise observed. Pleural effusions in the setting of intrathoracic extramedullary hematopoiesis have been attributed to mechanical interactions between the pleural surface and neighboring paravertebral masses consisting of hematopoietic tissue. Rupture of these highly vascularized lesions into the adjacent pleural space has been the putative mechanism in cases complicated by hemothorax. Histologically proven instances of islets of extramedullary hematopoiesis occurring on the pleural surface itself are exceedingly rare. Our case of a patient with myelofibrosis and massive pleural effusion is only the third such example described in the literature and the second to result in a confirmed hemothorax requiring surgery. As expected, technetium-99m sulfur (Tc-99m sulfur) colloid scanning accurately localized sites of extramedullary hematopoiesis in our patient, and there was a salutary response to radiation therapy.

Janus Kinase Inhibitors and Stem Cell Transplantation in Myelofibrosis

Myelofibrosis (MF) is characterized by splenomegaly, blood count abnormalities, particularly cytopenias, and a propensity for transformation to acute leukemia. The current treatment approach is to ameliorate symptoms due to these abnormalities. Treatment with Janus kinase 2 inhibitors reduces spleen size and improves symptoms in patients with MF, but most of the patients eventually have disease progression and stop responding. Allogeneic stem cell transplantation remains the only curative option. However, its efficacy must be balanced against the risk of treatment-related death and long-term sequelae of transplant like chronic graft versus host disease. The challenge is to integrate treatment with Janus kinase inhibitors with allogeneic stem cell transplantation.

Nontuberculous mycobacterial infection in a patient with myelofibrosis: case report and concise review

A 70-year-old patient having massive refractory ascites in the course of idiopathic myelofibrosis was diagnosed of peritoneal extramedullary hematopoiesis and developed an overwhelming nontuberculous mycobacterial infection. The case describes this unusual infection and highlights the need for additional studies to confirm the etiology of ascites in primary myelofibrosis.

Agnogenic myeloid metaplasia with pulmonary hematopoiesis

Agnogenic myeloid metaplasia (AMM) is characterized by bone marrow fibrosis, splenomegaly and leukoerythroblastic anemia and is frequently accompanied by extramedullary hematopoiesis (EMH). Pulmonary interstitial EMH associated with myelofibrosis has rarely been described in the medical literature and is usually fatal. We report the case of a 77-year-old man with agnogenic myeloid metaplasia (AMM) treated with hydroxyurea, who seven years after diagnosis presented with dyspnea and severe hypoxemia. Radionuclide bone marrow scanning demonstrated increased tracer activity on the bases of both lungs, consistent with non-hepatosplenic EMH. Pulmonary EMH is rare in patients with AMM, but should be considered in patients with hypoxemia and respiratory distress.

Peritoneal EMH in a Dog with Immune-Mediated Hemolytic Anemia

Extramedullary hematopoiesis (EMH) is the process by which normal blood cells are produced outside the bone marrow. In humans, EMH effusions are rare and are characterized by the presence of megakaryocytes, immature erythrocytes, immature leukocytes, or combinations of those cells. To the authors’ knowledge, this is the first report to describe a case of peritoneal EMH effusion in a dog. A 5 yr old castrated male shorthaired dachshund presented with a 2 day history of pigmenturia and inappetence. A complete blood count revealed regenerative anemia with marked agglutination, spherocytosis, and an acute inflammatory leukogram characterized by a neutrophilia, regenerative left shift, and monocytosis. Ultrasound-guided aspiration of peritoneal effusion yielded a sample of high nucleated cellularity predominantly composed of mature and immature neutrophils and erythroid precursor cells. The patient was diagnosed with primary immune-mediated hemolytic anemia with concurrent EMH peritoneal effusion. The following case description and discussion explore the clinical findings associated with the unusual effusion and outline the possible pathogenesis by which the EMH effusion may have arisen in the dog.

Extramedullary haematopoiesis presented as intrathoracic tumour in a patient with alpha-thalassaemia

The authors report a case of extramedullary haematopoiesis (EMH) presenting as an intrathoracic tumour in a patient with alpha-thalassaemia. CT scan and MRI of the chest were obtained and followed by tumour excision. Compared to beta-thalassaemia, only two cases of EMH in patients with alpha-thalassaemia have been described in the literature. A possible reason for this disparity is discussed.

A case report on a patient who presented with myelofibrosis, developed breast cancer with myeloid metaplasia, and finally showed immature NK-cell leukemia or AML without maturation with CD56 expression transformation in the pleura with extramedullary hematopoiesis: a 25-year course

This study reports a female patient who suffered from primary myelofibrosis at 38 years of age, breast cancer with myeloid metaplasia at 49 years of age, and pleural effusion and multiple subcutaneous nodules at 62 years of age. She was finally diagnosed with immature NK-cell leukemia or AML without maturation with CD56 expression transformation of extramedullary hematopoiesis that developed in the pleura, and died 11 months later. Atypical cells in the pleural effusion had surface markers of CD13, CD33, CD34, and CD56 using a fluorescence-activated cell sorter analysis, and were positive for myeloperoxidase, CD34, CD43, and CD56 in a cell block material using an immunohistochemical method. Megakaryocytic and erythroblastic cells were also seen in the pleural effusion.

Myelofibrosis: an update on current pharmacotherapy and future directions

INTRODUCTION

Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by symptoms mainly derived from anemia and splenomegaly and constitutional symptoms and associated with a median survival around 6 years. Allogeneic stem cell transplantation (allo-SCT) remains the only curative therapy of MF but is applicable to a minority of patients. Discovery of the JAK2 mutation has provided the basis for the introduction of a new class of drugs, the JAK inhibitors, in the treatment of MF.

AREAS COVERED

A literature review on the therapy of MF has been performed through a PubMed search, with special attention being paid to the available data on transplantation, the JAK inhibitors, and other new drugs.

EXPERT OPINION

Conventional therapy of MF is usually adjusted to the predominant clinical symptoms in each patient, and its impact on survival is limited. Reduced-intensity conditioning regimens have increased the number of patients eligible for allo-SCT, but this procedure is still associated with substantial morbidity and mortality. The JAK inhibitors, such as ruxolitinib, can achieve profound symptomatic relief of the splenomegaly and the constitutional symptoms. However, they often accentuate the anemia and do not reduce the JAK2 allele burden, therefore lacking the potential to modify the natural history of MF.

Article Commentary: Symptomatic Splenomegaly in Polycythemia Vera: A Review of the Indications for Splenectomy and Perioperative Considerations

Polycythemia vera is a condition that surgeons do not commonly encounter. Advances in medical management have largely led to avoidance of surgical intervention in most patients. Indications and timing of splenectomy have been the subject of debate since the disease was first described in the late 19th century. Though anemia and thrombocytopenia associated with polycythemia vera only transiently respond to splenectomy, painful splenomegaly with infarction or compression of surrounding viscera are presently accepted indications for surgery. Special consideration must be given to polycythemia vera patients both preoperatively and postoperatively due to altered coagulation and anatomy. We present a review of the pathophysiology, medical treatment, indications for surgical intervention, and perioperative considerations for polycythemia vera.

Essential thrombocythemia, polycythemia vera, and myelofibrosis: current management and the prospect of targeted therapy

The recent discovery of JAK2 and/or MPL mutations in polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has had a major impact on how we diagnose and treat these disorders. For instance, the presence of a JAK2 mutation is now considered conditio sine qua non for the diagnosis of PV and the World Health Organization classification system has recently revised its diagnostic criteria for PV, ET, and PMF to include JAK2 and MPL mutations as clonal markers. From the standpoint of treatment, JAK-STAT is now identified as a legitimate target pathway for drug development in myeloproliferative neoplasms. Herein, I will first outline my views regarding current management in ET, PV, and PMF and then discuss emerging data on preclinical and clinical activity of anti-JAK2 small molecule drugs. Am. J. Hematol., 2008. (c) 2008 Wiley-Liss, Inc.

[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.

Tc-99m nanocolloid scintigraphic imaging of intracranial meningeal extramedullary hematopoiesis in a patient with idiopathic myelofibrosis

Meningeal extramedullary hematopoiesis (EMH) is a rare finding in idiopathic myelofibrosis. Intracranial EMH is typically asymptomatic and sites are usually found by chance. Diagnosis of EMH is difficult, based on clinical circumstances and the use of different diagnostic imaging modalities, such as CT, MRI or radionuclide imaging. We present a case with intracranial medullary hematopoiesis due to idiopathic myelofibrosis diagnosed with Tc-99m nanocolloid scintigraphy. Cranium SPECT images that were performed with Tc-99m nanocolloid showed increased radiotracer uptake in the bilateral parietal, bilateral frontal and left occipital bones and especially in falx cerebri of sinus sagittalis superior. In Tc-99m MDP bone scintigraphy, increased osteoblastic activity in the left frontal and parietal bones, in shoulders, knee and ankle joints, and in both metatarsal bones were seen. After gadodiamid injection, Tl weighted MRI showed diffuse contrast increased in the meningeal areas surrounding the brain. A biopsy of the mass revealed extramedullary hematopoiesis composed of erythroblasts, mature and immature myeloid cells, and megakaryocytes. It was deduced that these described foci of EMH.

Extramedullary Hematopoiesis-Related Pleural Effusion: The Case of β-Thalassemia

BACKGROUND

Thalassemia intermedia has a later clinical onset and a milder anemia than thalassemia major, characterized by high output state, left ventricle remodeling, and age-related pulmonary hypertension. Bone deformities, extramedullary hematopoiesis (EMH), and spleen and liver enlargement are the consequences of hypoxia and enhanced erythropoiesis. The EMH-related pleural effusion is rarely referred to in the literature of thalassemia.

METHODS

We reviewed the thalassemia patients' medical records hospitalized for pleural effusion in our Department, within the last 6 years.

RESULTS

Eight (4 men) thalassemia intermedia patients admitted for symptomatic pleural effusion were identified. Common clinical findings on admission were dyspnea and apyrexia. Their mean hemoglobin level was 7.15 +/- 0.64 g/dL. Radiology revealed intrathoracic EMH and pleural effusion in all patients: exudative in seven patients and massive hemothorax in one. Cytologic fluid analysis was negative for malignancy. Fluid and serum cultures, antibodies, and stains were negative for viral, bacterial, and fungal infection. The hemothorax case was successfully treated with repeated aspirations, transfusions, and hydroxyurea. Although repeated thoracentesis and radiation could not control the effusions in the rest of the cases, pleurodesis was successful in 5 patients, without serious adverse events. Treatment was further accomplished with hydroxyurea. No relapses were observed in the mean 30 month follow-up period.

CONCLUSIONS

Afebrile, EMH-related pleuritis represents a potentially life-threatening complication in thalassemia. Therapy should be individualized and treatment is emerging. Pleurodesis seems to be an effective and safe therapeutic option for exudative effusions, while transfusion-chelation therapy combined with hydroxyurea may be helpful in suppressing increased erythropoiesis.

Idiopathic myelofibrosis: pathogenesis to treatment

Idiopathic myelofibrosis (IMF) is the least common of the chronic myeloproliferative disorders and carries the worst prognosis with a median survival of 4 years. It is a clonal haematopoietic stem-cell disorder and, although the pathogenesis remains unclear, approximately 50% of cases are known to possess an activating JAK2 V617F mutation. In contrast, the characteristic stromal proliferation is a reactive, or secondary, event that results from the aberrant release of a variety of growth factors from megakaryocytes and monocytes. Treatment for most cases is supportive, although androgens, recombinant erythropoietin, steroids and thalidomide are effective modalities for the amelioration of anaemia. Myelosuppression, splenectomy and irradiation are valuable therapeutic modalities for specific clinical situations. Prognostic scores are available to aid the identification of cases for whom bone marrow transplantation should be considered. Recently, the use of reduced intensity conditioning has resulted in prolonged survival and lower transplant-related mortality. This review summarises the recent advances in the disease's pathogenesis and discusses the role of the various therapeutic options.

Mass-forming extramedullary hematopoiesis diagnosed by fine-needle aspiration cytology

Extramedullary hematopoiesis (EMH) is usually a microscopic finding. However, it may present as a mass-forming lesion making it amenable to fine-needle aspiration biopsy (FNAB). When mass-forming EMH occurs, it can simulate a neoplasm clinically and radiologically. Additionally, the megakaryocytes can mimic malignant neoplastic cells, particularly if EMH is not a considered diagnosis. We report six cases of mass-forming EMH diagnosed by FNAB and evaluate the utility of FNAB in diagnosing EMH. Four patients had prior diagnoses of hematologic disorders, one patient had malignant mastocytosis who presented with lymphadenopathy and one patient had a history of carcinoma. The patients' ages ranged from 46 to 78 yr with an equal sex distribution. Aspirate smears showed trilineage hematopoiesis. The cytomorphologic differential diagnosis included metastatic carcinoma, Hodgkin lymphoma and myeloid sarcoma. No special stains were necessary due to the classic cytologic findings and prior hematologic history.

Primary Extramedullary Hematopoiesis Manifesting As Massive Bilateral Chylothorax

Intrathoracic extramedullary hematopoiesis is a rare entity, mostly observed in patients with hematologic disorders. Extramedullary hematopoiesis is usually asymptomatic and is often located in the lower paravertebral sulci and rarely in the pleura. We report the case of a 54-year-old man without hematologic disorder or pleural malignancy who had a massive bilateral chylothorax develop due to primary pleural extramedullary hematopoiesis. He was successfully treated by bilateral video thoracoscopic talc pleurodesis and low-dose radiotherapy.

Clinical usefulness of In-111 chloride and Tc-99m Sn colloid scintigraphy in the diagnosis of intrathoracic extramedullary hematopoiesis

We report a case of intrathoracic extramedullary hematopoiesis associated with hemolytic anemia. While the paravertebral localization of the lesions demonstrated on CT and MRI was suspicious of intrathoracic extramedullary hematopoiesis, In-111 chloride and Tc-99m Sn colloid bone marrow scintigraphies showing a bone marrow element of the lesion were useful to confirm the diagnosis.

Modern management of myelofibrosis

The conventional treatment of myelofibrosis involves a wait-and-see approach for asymptomatic patients, oral chemotherapy for the hyperproliferative forms of the disease, androgens or erythropoietin for the anaemia, and splenectomy in selected patients. Low-dose thalidomide plus prednisone is a well-tolerated therapy for the anaemia and the thrombocytopenia of myelofibrosis, whereas imatinib has shown little efficacy. Allogeneic stem cell transplantation (allo-SCT) is the only curative therapy for myelofibrosis. Its standard modality has an associated mortality of about 30% and can be applied to younger patients with high-risk disease or resistant to conventional treatment. Reduced-intensity conditioning allo-SCT involves a low mortality and is a promising therapy for patients aged 45-70 years old with the above characteristics. Autologous SCT is a palliative therapy for patients resistant to conventional treatment who lack a suitable donor. The next candidates for the treatment of myelofibrosis are the thalidomide derivatives, the proteasome inhibitors, and vascular endothelial growth factor neutralizing antibodies.

Myelofibrosis with myeloid metaplasia: new developments in pathogenesis and treatment

Myeloid metaplasia with myelofibrosis (MMM) is a chronic myeloproliferative disorder (CMPD) characterized by progressive anemia, massive splenomegaly, both hepatosplenic and non-hepatosplenic extramedullary hematopoiesis (EMH), a leukoerythroblastic blood smear, circulating progenitor cells, and marked bone marrow stromal reaction including collagen fibrosis, osteosclerosis and angiogenesis. The overall median survival is 5 years although it might range from 2 to 15 years depending on the presence or absence of clinically defined prognostic factors. Death is often due to leukemic transformation, portal hypertension or infection. In addition to shortened survival, quality of life is often affected by frequent red blood cell transfusions, profound constitutional symptoms, and cachexia. Drug therapy and autologous hematopoietic stem cell transplantation (HSCT) are of only palliative value and have not been shown to improve survival. The role of allogeneic HSCT, both myeloablative and non-myeloablative, is actively being investigated. Both splenectomy and radiation therapy have defined therapeutic roles to control EMH-associated symptoms. Analysis of the molecular biology of the disease is underway with the aid of animal models leading to the identification of novel therapeutic targets. Among the novel agents tested, thalidomide seems the most promising although newer agents are on the horizon.

Fatal Hemothorax Due to Rupture of an Intrathoracic Extramedullary Hematopoietic Nodule

Intrathoracic extramedullary hematopoiesis (TEMH) is an unusual but well-described entity, which is typically found in patients who have chronic hemolytic anemias, myelofibrosis, or myeloproliferative disorders. It is seldom symptomatic, rarely fatal. We report a case of a 26-year-old African-American male with a past medical history of sickle cell trait/beta thalassemia who developed multiple intrathoracic nodules of extramedullary hematopoiesis. One of these nodules spontaneously ruptured and produced a fatal hemothorax.

Hemothorax due to extramedullary erythropoietic masses

We describe a 27-year-old male patient suffering from beta-thalassemia intermedia who presented with a nontraumatic spontaneous hemothorax due to extramedullary hemopoietic foci. In reviewing the literature, four similar reports were found. The details of this unusual entity are discussed.

An interesting presentation of intrathoracic extramedullary hematopoiesis in a patient with thalassemia intermedia

Extramedullary hematopoiesis (EMH) occurs as a compensatory mechanism for bone marrow dysfunction in severe thalassemia. In addition to the more common locations, such as liver, spleen and lymph nodes, a mass of EMH may occasionally occur in the thorax. Intrathoracic EMH is usually asymptomatic. A 69-year-old woman who initially presented with hematuria, dysuria, and left inguinal pain was found to have paravertebral masses in the thorax. Histopathologic examination of a CT-guided needle aspiration biopsy of the masses showed the presence of trilineage hematopoiesis. We present this unusual case, in which EMH was diagnosed by chance in an elderly patient with no symptoms related to thalassemia.

Nonhepatosplenic extramedullary hematopoiesis: associated diseases, pathology, clinical course, and treatment

OBJECTIVE

To define associated clinical conditions, pathology, natural history, and treatment outcome of nonhepatosplenic extramedullary hematopoiesis (NHS-EMH).

PATIENTS AND METHODS

We retrospectively reviewed the medical charts of all patients identified as having NHS-EMH from 1975 to 2002. Diagnosis was made by tissue biopsy, fine-needle aspiration biopsy, or radionuclide bone marrow scanning.

RESULTS

We identified 27 patients with antemortem diagnosis of NHS-EMH. The most common associated condition and disease site were myelofibrosis with myeloid metaplasia (MMM) (in 18 patients [67%]) and the vertebral column (in 7 patients [26%]; all involving the thoracic region), respectively. At the time of diagnosis of NHS-EMH, concurrent splenic EMH (in 22 patients [82%]; 15 [56%] had undergone splenectomy) and red blood cell transfusion dependency (in 12 patients [44%]) were prevalent. Of the 27 patients, 9 (33%) required no specific therapy. Specific therapy was radiation (in 7 patients with a 71% response rate) and surgical excision (in 6 patients with a 67% response). Treatment-associated complications were limited to surgery. Radiation therapy was not used in the non-MMM group, but low-dose radiation therapy was used in the MMM group for paraspinal or intraspinal EMH (median dose, 1 Gy; range, 1-10 Gy), pleural or pulmonary disease (median dose, 1.25 Gy; range, 1.00-1.50 Gy), and abdominal or pelvic disease (median dose, 2.02 Gy; range, 150-4.50 Gy). Median survival after the diagnosis of NHS-EMH was 13 months in the MMM group and 21 months in the non-MMM group.

CONCLUSIONS

This retrospective study suggests that NHS-EMH is rare, is often associated with MMM, and preferentially affects the thoracic spinal region. Asymptomatic disease may require no specific treatment, whereas symptomatic disease is best managed with low-dose radiation therapy.

Myelofibrosis with myeloid metaplasia

MMM is a chronic myeloproliferative disorder characterized by bone marrow fibrosis and neoangiogenesis, constitutive release ofa high number of CD34+ stem cells from the bone marrow, and extramedullary hematopoiesis. It presents with heterogeneous clinical features in which anemia and progression to symptomatic splenomegaly dominate. The pathogenesis is undefined, but the dual action of deregulation of the bFGF pathway may influence myeloproliferation, myelofibrosis, and neoangiogenesis. Animal models suggest that chronic exposure to high doses of thrombopoietin or impairment of the capacity of megakaryocytes to differentiate into platelets, as occurs in the GATA-1(low) mice, is a necessary event for myelofibrosis. Allogeneic stem cell transplantation offers a chance of cure, and low conditioning regimens may extend the age of transplantable patients with lower mortality. Autologus stem cell transplantation and splenectomy are risky procedures that may be considered in patients with advanced disease when conventional therapies for correcting anemia (danazol, recombinant human erythropoietin, or cyclosporine) or chemotherapy for splenomegaly and myeloproliferation (hydroxyurea or interferon alfa) have failed. Thalidomide has been tested in numerous series, and its capacity to improve anemia and thrombocytopenia while reducing splenomegaly has been documented.

The forgotten myeloproliferative disorder: myeloid metaplasia

Myelofibrosis with myeloid metaplasia is a hematologic disorder currently classified with polycythemia vera and essential thrombocythemia as a chronic myeloproliferative disease. The median age at diagnosis is 60 years, and more than 90% of patients are diagnosed after age 40 years. Clinical manifestations include massive splenomegaly, progressive anemia, profound constitutional symptoms, and extramedullary hematopoiesis. The diagnosis is confirmed by bone marrow examination after other causes of myelofibrosis are ruled out. Median survival is 5 years and causes of death include leukemic transformation. Prognosis is adversely affected by the presence of anemia (hemoglobin <10 g/dl), leukopenia or leukocytosis (white blood cells >30,000/ micro l), circulating blasts, and hypercatabolic symptoms. Conventional treatment is palliative and does not improve survival. In this regard, androgen preparations, corticosteroids, and erythropoietin are useful for the treatment of disease-associated anemia. Symptomatic splenomegaly is best managed by cytoreductive therapy or surgical removal. Radiation therapy is most useful in the treatment of nonhepatosplenic extramedullary hematopoiesis. New treatment approaches include the use of thalidomide alone or in combination with prednisone and hematopoietic stem cell transplantation.

Treatment approaches in myelofibrosis with myeloid metaplasia: the old and the new

Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a chronic myeloproliferative disorder (CMPD) and is characterized by prominent bone marrow stromal reaction including collagen fibrosis, osteosclerosis, and angiogenesis. Among the CMPD, MMM carries the worst prognosis with an overall median survival of 5 years; the clinical course is marred by profound constitutional symptoms, progressive anemia, and symptomatic splenomegaly. Causes of death include leukemic transformation, which occurs in approximately 10% of patients in the first decade of the disease. At present, allogeneic hematopoietic stem cell transplantation (HSCT) is the only treatment modality that has the potential to either cure the disease or prolong survival. Both drug therapy and autologous HSCT are currently palliative. Conventional treatment agents in MMM include androgen preparations, corticosteroids, erythropoietin (EPO), and hydroxyurea. In addition, both splenectomy and radiation therapy have defined therapeutic roles. Thalidomide is the most effective investigational agent at the present time. Optimal therapy for an individual patient requires a sound understanding of disease risk factors, as well as a full appreciation of the risk to benefit ratio for a specific treatment modality.

Thalidomide treatment in myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is uniquely characterized by macroscopic bone marrow stromal changes that are believed to be both reactive and cytokine mediated. Furthermore, a prognostically detrimental increase in bone marrow angiogenesis has recently been demonstrated. These observations suggest a potential therapeutic role for agents that are inhibitory to angiogenesis as well as cytokines that are pathogenetically implicated in MMM. In a prospective study of 15 patients with MMM, thalidomide treatment, starting at a dose of 200 mg/d, resulted in increased platelet counts (12 of 15 patients), increased haemoglobin level (3 of 15), a modest decrease in spleen size (3 of 12), increased bone marrow megakaryopoiesis (5 of 9) and decreased bone marrow angiogenesis (2 of 9). Undesirable haematological effects included pericardial extramedullary haematopoiesis in one patient, marked leucocytosis in two patients and extreme thrombocytosis in three patients. The thrombocytosis occurred in both patients with post-thrombocythaemic myeloid metaplasia (PTMM) and was also associated with higher baseline levels of circulating CD34+ cells. Previously described toxicities of thalidomide were seen in the majority of patients and dose escalation to 400 mg/d was permitted in only two patients. In contrast, toxicity-related dose reductions to 50 mg/d did not appear to lessen drug efficacy. We conclude that thalidomide has both beneficial and potentially adverse biological activity in MMM. A lower dose of the drug might be more tolerable without compromising therapeutic value. Patients with PTMM and/or markedly increased circulating CD34+ cell counts might be susceptible to thalidomide-induced thrombocytosis.

Extramedullary hematopoiesis in a patient with beta-thalassemia intermedia manifesting as symptomatic pleural effusion

A case of bilateral paravertebral extramedullary hematopoietic masses with symptomatic pleural effusion in a patient with beta-thalassemia intermedia is reported. The pleural effusion was controlled by pleurodesis using tetracycline. We review the literature on this uncommon complication of beta-thalassemia intermedia and discuss the options for diagnosis and treatment.

Radiation therapy for symptomatic hepatomegaly in myelofibrosis with myeloid metaplasia

OBJECTIVE

To describe the experience with liver irradiation in advanced cases of myelofibrosis with myeloid metaplasia (MMM).

METHODS

Over a 20-yr period, 14 patients with MMM were treated with a total of 25 courses of liver, abdominal, or abdominal and pelvic irradiation for symptomatic hepatomegaly with (5 patients) or without (9 patients) ascites. All 14 patients had advanced disease and 11 (79%) had previous splenectomy. The median radiation therapy (RT) dose per course was 150 cGy (range 50-1000) administered at a median of six fractions. Four patients received two to six courses.

RESULTS

Twelve of the 14 patients (86%) had a transient (median 3 months) subjective response from RT. However, in only 35% of these was there a transient (median 3 months) decrease in palpable liver size. Four of the five patients with ascites experienced a short-term response from RT. Eight of the 13 patients suitable for evaluation (62%) had treatment-associated cytopenia, often in the form of anemia and/or thrombocytopenia. At last follow-up, 10 patients (71%) had died after a median of 7 months (range 0.1-23) and 4 were alive at 3, 20, 33, and 57 months after RT.

CONCLUSIONS

Low-dose abdominal RT for symptomatic hepatomegaly or ascites associated with advanced-stage MMM is myelosuppressive and provides only temporary and mainly subjective and short-lived relief.

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.

Myelofibrosis with myeloid metaplasia: diagnostic definition and prognostic classification for clinical studies and treatment guidelines

PURPOSE

Myelofibrosis with myeloid metaplasia (MMM) is a chronic myeloproliferative disorder characterized by bone marrow fibrosis and extramedullary hematopoiesis. Recent studies provide definite diagnostic criteria and prognostic classifications of the disease, and allogeneic stem-cell transplantation (SCT) now offers a chance of curing the disease. In order to put diagnostic criteria and prognostic classifications of the disease into the perspective of developing guidelines for treatment strategies, all studies published in the English literature over the last 30 years were reviewed.

MATERIALS AND METHODS

Studies were identified through a MEDLINE search (1966 to present) and from the bibliographies of relevant articles.

RESULTS

The Italian Consensus Conference on diagnostic criteria is a structured enterprise aimed at formulating a definition of MMM that will be used for enrolling patients onto clinical studies. It relies on the obligatory presence of myelofibrosis and on the exclusion of the BCR-ABL rearrangement or Philadelphia chromosome, in association with combinations of traditional features. Prognostic scores allow us to identify classes of patients on the basis of hemoglobin, age, WBC count, and chromosomal abnormalities. Several nonrandomized studies have indicated that allogeneic SCT for patients under the age of 55 is effective in prolonging survival in more than 50% of cases and in possibly curing the disease. Patients with the most severe prognosis are candidates.

CONCLUSION

"Consensus" methodology offers a definition of MMM useful for conducting and reporting clinical studies. A detailed knowledge of prognostic factors can help to delineate guidelines for addressing patients with allogeneic SCT.

Bilateral pleural effusions in a beta-thalassemia intermedia patient with posterior mediastinal extramedullary hematopoietic masses

Intractable bilateral exudative pleural effusions developed, following systemic sepsis without pulmonary infection, in a beta-thalassemia intermedia patient with longstanding mediastinal hematopoietic masses. The pleura were not infiltrated by hematopoietic cells. Bilateral talc pleurodesis successfully controlled the effusions.

Craniocephalic disproportion with increased intracranial pressure and brain herniation: a new clinical syndrome in anemic patients: report of two cases

OBJECTIVE AND IMPORTANCE

We describe a new clinical syndrome in two patients with chronic anemia. The major manifestation of the syndrome is herniation of the brain resulting in death caused by longstanding craniocephalic disproportion. The disproportion was caused by extreme thickening of the cranium because of erythroid hyperplasia.

CLINICAL PRESENTATION

Two patients with known chronic anemia presented with chronic increase in intracranial pressure with acute deterioration resulting in brain herniation.

INTERVENTION

Despite maximum medical therapy, both patients died as a result of uncontrollable increase in intracranial pressure.

CONCLUSION

Patients with chronic anemia presenting with progressive headaches should be monitored for this newly described clinical phenomenon.