Case 9
History:
27 year old man with chronic condition and acute chest and abdominal pain
Findings:
Enhanced CT of the abdomen showing bilateral paraspinal and presacral soft tissue. (The patient had a prior studies showing the lesion to be stable).
Diagnosis:
Extramedullary hematopoiesis
Discussion:
Extramedullary hematopoiesis refers to the location of hematopoietic elements in locations other than the bone marrow medullary space most often seen in chronic anemias. Most often, it is microscopic and asymptomatic, but it can manifest as organomegaly and tumor-like masses. Intrathoracic EMH usually presents as paraspinal masses and can be confused with neurogenic tumors, lymphoma, metastasis, paravertebral abscess, and lateral meningocele. Associated bone changes manifested by marrow expansion, cortical thinning and trabecular rarefaction are often present. These lesions are usually slow-growing and do not cause any significant bone erosion. Chronic, inactive lesions may reveal iron and/or fatty deposition. Radionuclide imaging with technetium-99m sulfur colloid may reveal extrahepatosplenic uptake of colloid. Fine-needle biopsy can confirm the diagnosis.
