Imaging features of focal intrahepatic extramedullary haematopoiesis

Extramedullary hematopoiesis (EMH) in the liver allograft presenting with a mass-like lesion

This is a rare case of extramedullary hematopoiesis (EMH) presenting as a mass-like lesion in liver allograft. Our patient was a 57-year-old woman who had undergone liver transplantation due to hepatic epithelioid hemangioendothelioma. She presented with an ill-defined hypoechoic lesion on ultrasound which showed features of focal EMH on pathologic examinations. While transient intrahepatic hematopoiesis has been reported in liver transplant patients, focal EMH mass lesion is a rarely encountered phenomenon. Therefore, focal EMH may need to be considered as a differential diagnosis when encountering a mass in post liver transplant patients.

Extramedullary Hematopoiesis: A Forgotten Diagnosis and a Great Mimicker of Malignancy

ABSTRACT

Radiology errors have been reported in up to 30% of cases when patients have abnormal imaging findings. Although more than half of errors are failures to detect critical findings, over 40% of errors are when findings are recognized but the correct diagnosis or interpretation is not made. One common source of error is when imaging findings from one process simulate imaging findings from another process but the correct diagnosis is not made. This can result in additional imaging studies, unnecessary biopsies, or surgery. Extramedullary hematopoiesis is one of those uncommon disease processes that can produce many imaging findings that may lead to misdiagnosis. The objective of this article is to review the common and uncommon imaging features of extramedullary hematopoiesis while presenting a series of interesting relevant illustrative cases with emphasis on CT.

Magnetic resonance imaging features of intrahepatic extramedullary hematopoiesis: Three case reports

BACKGROUND

Extramedullary hematopoiesis rarely occurs within the liver alone, and is easily misdiagnosed. The radiological literature on this disease is exclusively case reports. There is a paucity of literature on the role of magnetic resonance imaging (MRI). The most common imaging modalities used are computed tomography and ultrasound. This report aims to provide more data on the appearance of extramedullary hematopoiesis using MRI to help radiologists establish the diagnosis.

CASE SUMMARY

Three patients (one male and two females) were incidentally found to have a hepatic mass or nodule, without hepatomegaly or splenomegaly. Laboratory tests including liver function, serum hepatic tumor markers, and hepatitis serologic markers were normal. On MRI scans, all lesions showed lower signal intensity on in-phase images than on out-phase images. One case showed changes in signal intensity on T2 weighted images (WI) and diffusion WI, which shifted from hyperintensity to hypointensity with size enlargement between two rounds of imaging examination. These lesions exhibited different enhancement patterns on dynamic contrast enhancement series.

CONCLUSION

The MRI signal change and in-/out-phase image might provide useful information and help radiologists establish the diagnosis of intrahepatic extramedullary hematopoiesis.

MRI Appearance of Focal Lesions in Liver Iron Overload

Liver iron overload is defined as an accumulation of the chemical element Fe in the hepatic parenchyma that exceeds the normal storage. When iron accumulates, it can be toxic for the liver by producing inflammation and cell damage. This can potentially lead to cirrhosis and hepatocellular carcinoma, as well as to other liver lesions depending on the underlying condition associated to liver iron overload. The correct assessment of liver iron storage is pivotal to drive the best treatment and prevent complication. Nowadays, magnetic resonance imaging (MRI) is the best non-invasive modality to detect and quantify liver iron overload. However, due to its superparamagnetic properties, iron provides a natural source of contrast enhancement that can make challenging the differential diagnosis between different focal liver lesions (FLLs). To date, a fully comprehensive description of MRI features of liver lesions commonly found in iron-overloaded liver is lacking in the literature. Through an extensive review of the published literature, we aim to summarize the MRI signal intensity and enhancement pattern of the most common FLLs that can occur in liver iron overload.

Oxaliplatin-induced haematological toxicity and splenomegaly in mice

PURPOSE

Haematological toxicities occur in patients receiving oxaliplatin. Mild anaemia (grade 1-2) is a common side effect and approximately 90% of recipients develop measurable spleen enlargement. Although generally asymptomatic, oxaliplatin-induced splenomegaly is independently associated with complications following liver resection for colorectal liver metastasis and separately with poorer patient outcomes. Here, we investigated oxaliplatin-induced haematological toxicities and splenomegaly in mice treated with escalating dosages comparable to those prescribed to colorectal cancer patients.

METHODS

Blood was analysed, and smears assessed using Wright-Giemsa staining. Paw coloration was quantified as a marker of anaemia. Spleen weight and morphology were assessed for abnormalities relating to splenomegaly and a flow cytometry and multiplex cytokine array assessment was performed on splenocytes. The liver was assessed for sinusoidal obstructive syndrome.

RESULTS

Blood analysis showed dose dependent decreases in white and red blood cell counts, and significant changes in haematological indices. Front and hind paws exhibited dose dependent and dramatic discoloration indicative of anaemia. Spleen weight was significantly increased indicating splenomegaly, and red pulp tissue exhibited substantial dysplasia. Cytokines and chemokines within the spleen were significantly affected with temporal upregulation of IL-6, IL-1α and G-CSF and downregulation of IL-1β, IL-12p40, MIP-1β, IL-2 and RANTES. Flow cytometric analysis demonstrated alterations in splenocyte populations, including a significant reduction in CD45+ cells. Histological staining of the liver showed no evidence of sinusoidal obstructive syndrome but there were signs suggestive of extramedullary haematopoiesis.

CONCLUSION

Chronic oxaliplatin treatment dose dependently induced haematological toxicity and splenomegaly characterised by numerous physiological and morphological changes, which occurred independently of sinusoidal obstructive syndrome.

Extramedullary haematopoiesis presenting as a periportal mass

Extramedullary haematopoiesis (EMH) is defined as haematopoiesis occurring in organs outside the bone marrow. The liver is one of the rare sites of EMH, and to the best of our knowledge, a few cases of adult EMH of the liver have been reported in the last 20 years. Here, we reported the case of a 68-year-old man with a known history of myelofibrosis presented with vague abdominal pain. An abdominal CT scan showed a hypoattenuating periportal mass encasing the portal vein. The final diagnosis of EMH was made through the histopathological examination. This is a rare presentation of EMH, which may be easily mistaken for other pathologies such as metastases. Familiarity with this type of presentation aids in correctly diagnosing it in an appropriate clinical setting.

Marrow outside marrow: imaging of extramedullary haematopoiesis

Extramedullary haematopoiesis (EMH) refers to the formation of non-neoplastic blood cell lines outside the bone marrow and is a common incidental finding when patients with haematological disorders are imaged. EMH presenting as mass (tumefactive EMH) has long been a radiological conundrum as it resembles neoplasms. Several imaging findings have been described in EMH, and these vary depending on the activity of the underlying haematopoiesis. The older lesions are easier to diagnose as they often demonstrate characteristic findings such as haemosiderin and fat deposition. In comparison, the newer, actively haematopoietic lesions often mimic neoplasms. Molecular imaging, particularly ^99mTc labelled sulphur colloid scintigraphy, may be helpful in such cases. Although imaging is extremely useful in detecting and characterising EMH, imaging alone is often non-diagnostic as no single mass shows all the typical findings. Hence, a judgement based on the clinical background, combination of imaging findings, and slow interval growth may be more appropriate and practical in making the correct diagnosis. In every case, an effort has to be made in providing an imaging-based diagnosis as it may prevent a potentially risky biopsy. When confident differentiation is not possible, biopsy has to be resorted to. This article describes the causes, pathophysiology, and theories underlying the genesis of EMH, followed by the general and location-specific imaging findings. The purpose is to provide a thorough understanding of the condition as well as enable the clinical radiologist in making an imaging-based diagnosis whenever possible and identify the situations where biopsy has to be performed.

The role of T2*-weighted gradient echo in the diagnosis of tumefactive intrahepatic extramedullary hematopoiesis in myelodysplastic syndrome and diffuse hepatic iron overload: a case report and review of the literature

Background

Extramedullary hematopoiesis is the proliferation of hematopoietic cells outside bone marrow secondary to marrow hematopoiesis failure. Extramedullary hematopoiesis rarely presents as a mass-forming hepatic lesion; in this case, imaging-based differentiation from primary and metastatic hepatic neoplasms is difficult, often leading to biopsy for definitive diagnosis. We report a case of tumefactive hepatic extramedullary hematopoiesis in the setting of myelodysplastic syndrome with concurrent hepatic iron overload, and the role of T2*-weighted gradient-echo magnetic resonance imaging in differentiating extramedullary hematopoiesis from primary and metastatic hepatic lesions. To the best of our knowledge, T2*-weighted gradient-echo evaluation of extramedullary hematopoiesis in the setting of diffuse hepatic hemochromatosis has not been previously described.

Case presentation

A 52-year-old white man with myelodysplastic syndrome and marrow fibrosis was found to have a 4 cm hepatic lesion on ultrasound during workup for bone marrow transplantation. Magnetic resonance imaging revealed diffuse hepatic iron overload and non-visualization of the lesion on T2* gradient-echo sequence suggesting the presence of iron deposition within the lesion similar to that in background hepatic parenchyma. Subsequent ultrasound-guided biopsy of the lesion revealed extramedullary hematopoiesis. Six months later, while still being evaluated for bone marrow transplant, our patient was found to have poor pulmonary function tests. Follow-up computed tomography angiogram showed a mass within his right main pulmonary artery. Bronchoscopic biopsy of this mass once again revealed extramedullary hematopoiesis. He received radiation therapy to his chest. However, 2 weeks later, he developed mediastinal hematoma and died shortly afterward, secondary to respiratory arrest.

Conclusions

Mass-forming extramedullary hematopoiesis is rare; however, our report emphasizes that it needs to be considered in the initial differential diagnosis of hepatic lesions arising in the setting of bone marrow disorders. We also show that in the setting of diffuse hepatic iron overload, tumefactive extramedullary hematopoiesis appeared isointense to background liver on T2* gradient-echo sequence, while adenoma, hepatoma, and hepatic metastasis appear hyperintense. Thus, T2*-weighted gradient-echo sequence may have a potential role in the imaging diagnosis of mass-forming hepatic extramedullary hematopoiesis arising in the setting of diffuse iron overload.

Idiopathic myelofibrosis with disseminated hepatosplenic, mesenteric, renal and pulmonary extramedullary haematopoeisis, portal hypertension and tuberculosis: initial presentation and 2 years follow-up

A 35-year-old man with a 12-year history of idiopathic myelofibrosis (IMF) presented in 2014 with fatigue and abdominal distension. CT scan revealed massive hepatosplenomegaly with focal splenic lesions, soft tissue around renal pelvis, mesenteric masses compressing bowel loops and perilymphatic nodules in lungs. There was portal hypertension, ascites, pleural effusion, bilateral psoas abscesses and necrotic retroperitoneal lymphadenopathy. MRI additionally revealed hypointense periportal infiltrative lesions in liver, not seen on CT scan. None of these lesions showed diffusion restriction. Biopsy from mesenteric masses revealed extramedullary haematopoeisis. Aspiration from psoas abscess confirmed tuberculosis. Follow-up after 6 weeks of ruxolitinib (JAK2 tyrosine kinase inhibitor) and 9 months of antitubercular therapy revealed resolution of psoas abscesses and lymph nodes. Mild reduction was noted in mesenteric masses and ascites while perirenal soft tissue had increased. Follow-up imaging after another 1 year of ruloxitinib showed new-onset bilateral paravertebral and presacral foci of extramedullary haematopoeisis.

A systematic review of presacral extramedullary haematopoiesis: a diagnosis to be considered for presacral masses

AIM

Presacral masses are uncommon and have malignant potential; treatment typically includes surgical excision. However, there are conditions such as extramedullary haematopoiesis (EMH) which are benign. The present study aimed to summarize the presentation of presacral EMH in our institution, to review the literature and to offer management strategies for this rare condition.

METHOD

The literature was searched for articles related to presacral EMH, and case reports were collected from articles meeting the inclusion criteria. We collected data on patient demographics, diagnostic investigation, management and the results of treatment.

RESULTS

Thirty-nine patients were included in the systematic review. Initial imaging included computed tomography (CT), magnetic resonance imaging (MRI) or ultrasound (US) suggestive of EMH. Some patients then underwent a technetium scan (n = 7, 18%), biopsy of the presacral lesion (n = 27, 69%) or excision of the entire mass (n = 3, 8%). All patients who underwent technetium scan were confirmed to have EMH, demonstrating enhancement similar to bone marrow. Patients who underwent technetium scan and presacral mass biopsy had concordant results confirming presacral EMH (n = 5, 13%). Data on management were available for 35/39 (90%) with most patients followed by clinical observation (n = 20, 51%). Symptomatic patients were treated with radiotherapy (15%), surgical excision (15%) or hydroxyurea (5%) and blood transfusions (10%). Most (81%, n = 17/21) patients whose outcome was reported remained asymptomatic or experienced pain relief.

CONCLUSION

Although uncommon, EMH should be considered in the differential diagnosis of a presacral mass. Presacral EMH is a benign condition that can be suspected on CT or MRI and confirmed with technetium scan. Patients may not necessarily need to undergo biopsy to confirm haematopoietic elements. Unlike other presacral masses, patients diagnosed with presacral EMH can be managed by observation. If symptomatic, radiotherapy or surgical excision may be offered.

Extramedullary hematopoiesis of the liver in a child with sickle cell disease: A rare complication

We present the case of a 7-year-old Cameroonian girl with sickle cell disease (SCD) who presented with progressive abdominal distension, fever, severe anemia, respiratory distress, and fatigue. Abdominal ultrasound showed a 15.3 cm × 11.5 cm × 15.5 cm solid echogenic mass within the left lobe of the liver. Fine-needle aspiration showed features of extramedullary hematopoiesis (EMH). Despite transfusions, antibiotics, and initiation of hydroxyurea the patient died of respiratory failure during the hospital stay. There is a paucity of information on EMH in the pediatric sickle cell population, especially from resource-limited settings such as western Africa. EMH, however, is a known complication of SCD and should be considered in patients presenting with mass lesions in the setting of chronic anemia. With limited therapeutic interventions for EMH, including radiation and hydroxyurea, the emphasis should be on improving overall treatment of patients with chronic and untreated hemolytic anemia, especially in low-income countries.

Comparative study of radiographic and laboratory findings between Beta thalassemia major and Beta thalassemia intermedia patients with and without treatment by hydroxyurea

Background:

In patients with thalassemia, chronic anemia causes bone marrow expansion and consequently skeletal manifestation in spine, skull, face and rib bones.

Objectives:

We aimed to compare chest radiographic findings and facial bone deformity in patients with thalassemia major (TM) and intermedia.

Patients and Methods:

In this cross sectional study, 86 consecutive thalassemia patients referring to the Thalassemia clinic in Shiraz, Southern Iran were evaluated during 2012. Patients were divided into three groups including TM and thalassemia intermedia (TI) with and without taking hydroxyurea (HU). Findings ofchest radiography (trabeculation, rib widening and paraspinal masses) as well as facial bone deformity were evaluated by an expert radiologist. Besides, laboratory findings were measured regarding hemoglobin, ferritin, NRBC and platelet count.

Results:

All radiologic findings were significantly higher in patients with TI compared to TM (P< 0.05). In patients with TI, only trabeculation was observed with a higher frequency in patients with HU compared to those without HU (68% vs. 27.3%, P= 0.008). In the regression model, from all variables evaluated, only NRBC showed a significant correlation with trabeculation (Exp B = 1.014, CI: 1.004-1.025, P = 0.008) and age showed a significant correlation with paravertebral mass (Exp B = 1.147, CI: 1.03-1.27, P = 0.013).

Conclusions:

In patients with TM, bone widening, trabeculation, paraspinal masses and facial bone deformity were lower than patients with TI, whichcan be related to effectiveness of therapy with blood transfusion irrespective of its adverse effects in TM patients.

CT and MR findings in extramedullary haematopoiesis with biliary system encasement: a case report

Extramedullary haematopoiesis is the production of blood elements outside the bone marrow cavity. In our case computed tomography and magnetic resonance imaging revealed the presence of a rare localization of extramedullary haematopoiesis with encasement of the biliary system in a 59 years-old male Caucasian patient, with chronic myelofibrosis and hepatic failure's symptomatology. Computed tomography detected the presence of homogeneous hypodense tissue around intra-hepatic bile ducts with minimal contrast enhancement, strongly suggestive for extramedullary haematopoiesis. Magnetic resonance confirmed the presence of a solid tissue surrounding the biliary tree, showing late enhancement after gadolinium administration suggestive for non-active lesion of extramedullary haematopoiesis. Final diagnosis was established by percutaneous biopsy.

Intrahepatic extramedullary hematopoiesis mimicking a hypervascular hepatic neoplasm on dynamic- and SPIO-enhanced MRI

We present a rare case of a focal intrahepatic extramedullary hematopoiesis (EMH) that mimicked a hypervascular hepatic neoplasm in a 33-year-old woman with idiopathic myelofibrosis. The lesion showed homogeneous and persistent enhancement on both contrast-enhanced CT and gadolinium-enhanced dynamic MR imaging. The lesion did not demonstrate an apparent signal drop on a T2^*-weighted sequence following administration of a superparamagnetic iron-oxide agent (SHU 555A). A hepatocellular adenoma was the initial radiological diagnosis. To the best of our knowledge, this is the first report of a histopathologically proven intrahepatic EMH evaluated with dynamic- and SPIO-enhanced MRI.

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.

Extramedullary haematopoiesis in liver of sudden infant death cases

AIMS

To determine the frequency of extramedullary haematopoiesis (EMH) in sudden infant death and control cases, and to provide descriptive data on extramedullary haematopoietic islands and diffuse cells.

METHODS

The study was carried out in 51 SIDS and 102 non-SIDS cases. Liver-tissue sections were stained with haematoxylin and eosin, and immunohistochemistry was done with streptavidin-biotin-peroxidase complexes by Polyclonal Haemoglobin "A" antibody. The prevalence of data was estimated statistically by Pearson chi-square test, descriptive statistics, and Kruskal-Wallis test.

RESULTS

The Pearson chi-square values (CI: 95%; OR: 0.071-0.49; p: 0.0474) show higher frequency of EMH islands in SIDS than in controls. The number of diffuse extramedullary haematopoetic cells was higher in SIDS cases compared to non-SIDS (p=0.017).

CONCLUSIONS

EMH is a frequent finding in SIDS cases, and this may be a consequence of anaemia associated with intrauterine hypoxia, or infections.

MRI features of intrahepatic extramedullary haematopoiesis in sickle cell anaemia

Extramedullary haematopoiesis (EMH) is a reactive mechanism by which blood cells are produced outside of the bone marrow to supplement insufficient production or increased destruction of erythrocytes. EMH is uncommon in sickle cell anaemia (SCA). We report the first case of focal intra-hepatic EMH in SCA depicted on MRI occurring in a 32-year-old woman with homozygote SCA and in view of previously published data, highlight the diagnostic features suggesting a differential diagnosis with other focal liver lesions including infectious, inflammatory or primary liver tumors.

Presacral extramedullary hematopoiesis: a diagnostic confusion concerning a rare presentation

OBJECTIVE

To report a rare case of extramedullary hematopoiesis (EMH) with an asymptomatic intrapelvic mass in a patient with thalassemia major.

CLINICAL PRESENTATION

The patient presented with a pelvic mass discovered by ultrasonography before undertaking laparoscopic cholecystectomy for gallstones. Technetium-99m MDP bone scan failed to differentiate EMH from malignancy. A fine-needle aspiration smear was misdiagnosed when atypical megakaryocytes were interpreted as malignant cells. EMH was suggested by magnetic resonance imaging and confirmed by an ultrasound-guided Tru-Cut biopsy.

CONCLUSION

This case report illustrates the need to consider EMH in the differential diagnosis of patients with chronic hematological disorders and mass lesions in extramedullary sites.

Benign focal liver lesions: spectrum of findings on SonoVue-enhanced pulse-inversion ultrasonography

The prevalence of benign focal liver lesions (BFLL) is high both in the general population and in patients with known malignancies. The gray-scale ultrasound (US) technique is usually the first-line imaging modality used in the radiological workup of such lesions, but unfortunately it lacks specificity. Furthermore, Doppler examination may often be unsatisfactory owing to motion artefacts, or when small or deeply located lesions are evaluated. Recently, microbubble-based contrast agents used in combination with gray-scale US techniques, which are very sensitive to nonlinear behavior of microbubbles, have led to a better depiction of both microvasculature and macrovasculature of focal hepatic masses, thus improving the reliability of using US in the assessment of liver tumors. This review illustrates the spectrum of enhancement patterns of BFLL on contrast-enhanced ultrasonography with SonoVue, a second-generation microbubble-based contrast agent.