Extramedullary hematopoiesis: Clinical and cytological features

Extramedullary Hematopoiesis Adjacent to Vertebral Fracture in a Patient with Pernicious Anemia: Support for a Mechanical Extrusion Mechanism

CASE

A 68-year-old woman presented with a paraspinal mass of indeterminate imaging characteristics. Workup and computed tomography-guided Fine Needle Aspiration (FNA) aspiration revealed extramedullary hematopoiesis (EMH) adjacent to a prior compression fracture in the setting of pernicious anemia.

CONCLUSION

The combination of findings suggests a possible relationship of the compression fracture and the EMH because of traumatic extravasation of marrow contents, with the patient's underlying anemia possibly providing an underlying predisposition to EMH.

Recurrent spinal cord compression due to extramedullary hematopoiesis in thalassemia patient: Case report

INTRODUCTION

Spinal cord compression secondary to extramedullary hematopoiesis (EMH) is a rare condition. Variable treatment options have been reported with different efficacy and recurrence rate. Due to its rarity, no clear optimal management guidelines have been established yet.

PATIENT CONCERNS AND DIAGNOSIS

We report a recurrence of spinal cord compression secondary to EMH in a 19-year-old male, with a background of transfusion-dependent beta-thalassemia on luspatercept, who presented with weakness in both lower limbs.

INTERVENTIONS AND OUTCOMES

He was treated successfully both times with radiotherapy.

CONCLUSION

Early diagnosis and management of EMH compressing the spinal cord are essential to prevent permanent neurological damage. Diagnosis should be suspected based on the clinical presentation and magnetic resonance imaging findings in a patient with a history of ineffective hemopoiesis. Treatment option remains controversial. Radiotherapy option seems effective, even in recurrent cases, and valid, particularly for those at high risk of surgery or who do not prefer it.

The Quantification and Significance of Extramedullary Hematopoiesis Seen on Liver Biopsy Specimens

OBJECTIVES

Extramedullary hematopoiesis (EMH) may occur in the liver and is often considered pathologic in adults. Many hematologic and nonhematologic disorders are associated with the development of EMH. However, it is unclear whether the presence of EMH is always pathologic. At present, no formal grading system for EMH in the liver exists.

METHODS

We reviewed 42 liver biopsy specimens with EMH and developed a novel grading system to quantify the degree of EMH from 1 to 3 based on the number of EMH foci in 10 high-power fields.

RESULTS

Most patients had nonhematologic conditions (n = 25). Seventeen patients had a hematologic condition, most frequently a myeloproliferative neoplasm (n = 9). Patients with an underlying hematologic condition had a significantly higher EMH grade compared with those without a hematologic condition (P < .0001). All patients with grade 3 EMH had an underlying hematologic diagnosis, and most (86%) patients with grade 1 EMH had a nonhematologic disorder.

CONCLUSIONS

Our data suggest that EMH grading in the liver is feasible and can identify patients who may have an underlying hematologic condition, which can guide further diagnostic workup.

Extramedullary Hematopoiesis of the Liver and Spleen

Hematopoiesis is the formation of blood cellular components and, consequently, immune cells. In a more complete definition, this process refers to the formation, growth, maturation, and specialization of blood cells, from the hematopoietic stem cell, through the hematopoietic progenitor cells, to the s pecialized blood cells. This process is tightly regulated by several elements of the bone marrow microenvironment, such as growth factors, transcription factors, and cytokines. During embryonic and fetal development, hematopoiesis takes place in different organs: the yolk sac, the aorta–gonad mesonephros region, the lymph nodes, and not lastly, the fetal liver and the spleen. In the current review, we describe extramedullary hematopoiesis of the spleen and liver, with an emphasis on myeloproliferative conditions.

Adult Hepatocellular Carcinoma Coexisting with Extramedullary Hematopoiesis

Extramedullary hematopoiesis (EMH) in adults usually occurs in the liver, spleen, and lymph nodes when bone marrow hematopoiesis fails. EMH has also been recognized in benign or malignant hepatic tumors, such as hepatoblastoma, hepatocellular adenoma, and vascular tumors. However, it is rarely encountered in hepatocellular carcinoma (HCC) in elderly adults, and the molecular mechanism of EMH in hepatic tumors remains unclear. We present a case of a 74-year-old man without any hematopoietic disorders and hepatitis viral infection who underwent hepatic resection for HCC. Histological examination revealed a well-differentiated HCC with trilineage hematopoiesis in the tumor and non-neoplastic liver. The coexistence of HCC and EMH in adult patients with no hematopoietic disorders is very rare and must be distinguished from poorly differentiated or dedifferentiated HCC and hepatoblastoma.

Case Report: An Undefined Liver Lesion in a Young Man With Severe Aplastic Anemia: A Teachable Moment

In this work, we reported a young man complaining of asthenia and intermittent fever for 10 days, and an ultrasound showed an undefined lesion on his liver. Facing the patient's situation with severe agranulocytosis, anemia, and thrombocytopenia, we passed through a tough diagnostic process for choosing an appropriate treatment for him with an ambiguous result of pathological biopsy. The undefined liver lesion was successfully solved by withdrawing the androgen for observation, without lobectomy. The lesion gradually diminished over 2 years of follow-up.

A rare cause of lumbar nerve root compression: Extramedullary hematopoiesis in a patient with thalassemia major

Extramedullary hematopoiesis (EMH) can rarely involve the epidural space, leading to spinal cord compression syndrome. No treatment guidelines have been established yet.