Spinal Cord Compression due to Extramedullary Hematopoiesis in the Proliferative Phase of Polycythemia vera

Abstract

Extramedullary hematopoiesis is a common accompaniment of a variety of hematologic diseases such as hereditary spherocytosis, thalassemia and myelofibrosis. The association of extramedullary hematopoiesis with polycythemia vera in the proliferative phase is much less usual. We report a patient who presented with paraplegia due to spinal cord compression; clinical investigation revealed a paravertebral hematopoietic tumor, and the diagnosis of polycythemia vera was then established.

Paraspinal and Presacral Extramedullary Hematopoiesis: A Rare Manifestation of Polycythemia Vera

“…EMH is seen in various hematological disorders such as myelofibrosis, polycythemia vera, lymphoma, leukemia or post-bone marrow irradiation (6, 7). There are various sites in the body that are involved in EMH like the spleen, liver, thymus, breast, lung pleura, heart, kidneys, prostate, suprarenal glands, ovaries, intestine, sclera, lymph nodes, retroperitoneal soft tissues, skin, peripheral and cranial nerves, and the spinal canal (8-12).…”

“…During the early phase of its evolution, immature and mature cells (predominantly erythroid and myeloid series) and dilated sinusoids containing precursors of red cells are found at the site of paraspinal EMH and later, the lesions become inactive revealing some fatty tissue, fibrosis or massive iron deposits (15). EMH is associated with chronic anemic states that is most commonly seen in cases of thalassemia; however, it is less common in other anemic and myeloproliferative disorders such as myelofibrosis and polycythemia vera (6). Rarely, it can cause cord compression, pleural effusion, massive hemothorax and respiratory failure.…”

Fine needle aspiration of an axillary lymph node in a patient suspected of having metastatic cancer of unknown primary

“…5,7 EMH occurs most frequently in the spleen, liver and lymph nodes, however it has also been described in the thyroid, endometrium, central nervous system, subcutaneous tissue, pleura, retroperitoneum, mediastinum, breast and kidney. [1][2][3][4][5][6][7]9,10,[13][14][15][16][17][18][19][20][21] Patients often present with symptoms related to the location of the EMH. EMH is seen mostly in neonates and the elderly.…”

“…2,6 A rare cause of EMH is polycythaemia vera (PV). [6][7][8] Fine needle aspiration (FNA) is a safe, relatively non-invasive technique often used to diagnose neoplasms and inflammatory diseases. 5 The cytological appearance of EMH obtained via FNA has been reported in the literature.…”

A patient with pancreatitis, anaemia and an intrathoracic tumour

“…In case of complications, such as symptoms from displacement or impression of organs or vessels (cardiac decompensation, venous congestion, distressed lung function) [10], and/or recurrent pleural effusions [15,16], haematothorax [17] or neurological symptoms [18,19], irradiation of the abnormal tissue formation could be the method of choice favoured by the high radiosensitivity of the myelopoietic tissue [20].…”