MR findings in hereditary spherocytosis

Asymptomatic spherocytosis presenting with spinal cord compression

✓ Extramedullary hematopoiesis (EMH) is a compensatory mechanism occurring in patients with chronic anemia, which occurs most frequently with thalassemia. The authors report the case of a 57-year-old man, with no history of clinical or hematological disease, presenting with spinal cord compression. Magnetic resonance (MR) imaging demonstrated a homogeneous posterior epidural mass extending from T-3 to T-6. Following decompressive surgery, the patient's symptoms improved. Histological analysis showed features consistent with a diagnosis of EMH. Subsequent workup was remarkable for an asymptomatic spherocytosis without anemia. There was no family history of anemia. An EMH-related presentation of mild spherocytosis has been described in the literature, but its epidural location led to spinal cord compression. The MR imaging features were suggestive of EMH, but in the presence of spinal cord compression and in the absence of a history of chronic anemia, the authors did not believe that nonsurgical management would have been reasonable.

[Bone marrow reconversion and magnetic resonance imaging: case report]

INTRODUCTION

Bone marrow is divided into red marrow mainly constituted of hemopoietic cells and fatty yellow marrow. In some situations, yellow marrow may be converted into red marrow and this process is called marrow reconversion. Magnetic resonance imaging may be misleading with an invading bone marrow neoplastic process.

EXEGESIS

We report a patient with non-Hodgkin's lymphoma with vertebral invasion. Clinical features at presentation were misleading with lower limbs migratory pain suggestive of inflammatory myositis. An MRI study of thigh muscles revealed femoral nodular lesions suggestive of bone marrow reconversion.

CONCLUSION

Bone marrow reconversion is a physiologic and reversible process. Awareness of its radiographic features may help to avoid a diagnostic biopsy procedure.

Extramedullary hematopoiesis in hereditary spherocytosis deficient in ankyrin: a case report

Hereditary spherocytosis (HS) is a common inherited hemolytic anemia due to red cell membrane defects. Extramedullary hematopoiesis is a compensatory response to insufficient bone marrow blood cell production. The preferred sites of extramedullary hematopoietic involvement are the spleen, liver, and lymph nodes, but in HS the posterior paravertebral mediastinum is also commonly involved. A nonsplenectomized 74-year-old man with mild HS, with primary deficiency in ankyrin, was found by magnetic resonance imaging to have thoracic paravertebral hematopoietic masses. The patient showed high serum levels of erythropoietin, which may have played a role in the development of extramedullary hematopoietic masses through a continuous hematopoietic stimulus to erythroid cells in the propositus. The long-standing history of respiratory infections and of hypoxia in the propositus may have been an additional etiological factor.