Thoracic Extramedullary Hematopoiesis Mimicking Metastatic Cancer

Abstract

Thoracic extramedullary hematopoiesis (EMH) is a rare manifestation in patients with myeloproliferative neoplasm. A 76-year-old woman with a long-standing history of polycythemia vera presented with a 2-month history of worsening dyspnea and left-sided wheezing. A chest computed tomography showed an ill-defined soft tissue mass encasing the left mainstem bronchus causing airway obstruction, associated with paratracheal and paraesophageal lymphadenopathy. Endobronchial ultrasound-guided fine needle aspiration of the soft tissue mass and mediastinoscopy with excisional biopsy of a paratracheal lymph node demonstrated EMH with increased myeloid blasts. A bone marrow biopsy confirmed postpolycythemic myelofibrosis consistent with progression of polycythemia vera to myelofibrosis. We describe the bronchoscopic management of a case of EMH presenting as a mediastinal mass, mimicking malignancy.

A rare cause for a posterior mediastinal lesion: extramedullary haematopoiesis

“…EMH is a recognized compensatory process that occurs in chronic anaemias in which the body attempts to maintain erythrogenesis 2 . EMH is linked to hemoglobinopathies and can present with paraparesis, sensory impairment, and occasionally sphincter disturbances 2,3 . EMH can be evaluated using CT, MRI, ultrasonography or technetium‐labelled scintigraphy 4 .…”

“…In hindsight, a radionucleotide imaging done earlier on to rule out thoracic splenosis could have prevented the patient from having thoracoscopy. Treatment of thoracic EMH depends on the presentation and the goal of treatment is aimed at treating the underlying haematological disorder 3 . Surgery is only recommended for patients who have complications secondary to the mass.…”

“…2 EMH is linked to hemoglobinopathies and can present with paraparesis, sensory impairment, and occasionally sphincter disturbances. 2,3 EMH can be evaluated using CT, MRI, ultrasonography or technetium-labelled scintigraphy. 4 MRI is the diagnostic procedure of choice, which shows isointense lobulated mass lesions seen in both T 1 and T 2 weighted imaging involving extradural portion of spinal canal and in paravertebral portions; hemorrhagic signal changes may be evident.…”

“…Treatment of thoracic EMH depends on the presentation and the goal of treatment is aimed at treating the underlying haematological disorder. 3 Surgery is only recommended for patients who have complications secondary to the mass.…”