Extramedullary hematopoietic tumor mimicking a thoracic nerve root schwannoma

Abstract

Extramedullary hematopoiesis secondary to chronic anemia is well reported throughout the literature. A rare presentation of this condition is in the central nervous tissue reported most frequently as an epidural mass causing spinal cord compression. The authors report the case of a 51-year-old man with β-thalassemia and chronic anemia who was found to have a 4-cm paravertebral mass suggestive of a schwannoma. The patient underwent transthoracic resection of the mass. Histological examination confirmed an extramedullary hematopoietic tumor. In this article the authors propose a method to distinguish extramedullary hematopoietic tumors from schwannomas. To the authors' knowledge, this is the first reported case in the neurosurgical literature of this phenomenon.

Epidural myelolipoma in a Silken Windhound

“…5 There are multiple reports of spinal cord compression due to extramedullary hematopoietic tumors in people afflicted with severe anemia, most commonly attributed to beta-thalassemia. [13][14][15][16] Similar findings were recently reported in a domestic shorthaired cat with chronic nonregenerative anemia and probable myelodysplasia. 17 In contrast, myelolipomas are not associated with hematologic disorders and tend to occur in significantly older patients.…”

“…In people, extramedullary hematopoietic tumors are typically located within the mediastinum or epidural space 5 . There are multiple reports of spinal cord compression due to extramedullary hematopoietic tumors in people afflicted with severe anemia, most commonly attributed to beta‐thalassemia 13–16 . Similar findings were recently reported in a domestic shorthaired cat with chronic nonregenerative anemia and probable myelodysplasia 17 .…”

A mass-forming extramedullary hematopoiesis case mimicking mediastinal neoplasia

“…There are wide varieties of pathologic conditions in which disturbance of the normal blood-forming marrow may be associated with the formation of extramedullary hematopoietic tissue. Common causes of EMH include spherocytic anemia, erythroblastosis of newborn, thalassemia, pernicious anemia in the period of relapse, macrocytic anemia of hepatic origin, carcinomas with bone marrow invasion, Hodgkin's disease, lymphoma, leukemia, osteosclerosis and myeloproliferative syndrome [1][2][3][4][5][6][7][8].…”

“…It is usually diagnosed incidentally and, presents rarely as a posterior mediastinal mass, mimicking any kind of a mediastinal tumor. Intrathoracic EMH is a rare pathology and only very few case reports have been described in patients with chronic myeloproliferative disorders, especially myelofibrosis with myeloid metaplasia, anemia, thalassemia-sickle-cell anemia, MYH9-related thrombocytopenia, polycythemia and spherocytic anemias [1][2][3][4][5][6][7][8][9]. The patients with EMH, are most commonly asymptomatic or have symptoms related to anemia such as fatigue and dizziness.…”

Extramedullary hematopoiesis involving the central nervous system and surrounding structures

“…It most often occurs in cranial meninges [13][14][15][16][17], followed by spinal meninges and paraspinal tissue [7,18], and intracerebral locations [8]. In addition, EMH foci have been reported in central (most often optic nerve) and peripheral nerves [19,20], choroid plexus [21], in and around pituitary gland [22] as well as in orbital [23] and lacrimal fossae [24], and sphenoid sinus [25]. There is no sex predilection [17].…”