Author/Authors :
Paydaş, Semra Çukurova Üniversitesi - Tıp Fakültesi İç Hastalıkları Anabilim Dalı - Onkoloji Bilim Dalı, Turkey
Abstract :
Myeloproliferative neoplasms (MPN) arise from genetic deficiencies at the level of pluripotent stem cells. Each of these neoplasms is a clonal stem cell disorder with specific phenotypic, genetic and clinical properties. Age is one of the most important factors in the development of symptoms and complications associated with MPNs. High white blood cell counts in chronic myelocytic leukemia also known as leukocytosis may lead to central nervous system findings. Tumors developing outside the bone marrow named as extramedullary myeloid tumors (EMMT) could be detected at the initial diagnosis or during the prognosis of the disease, which may cause neurological symptoms due to pressure of leukemic cell mass on various tissues along with spinal cord. Central nervous system involvement and thrombocytopenic hemorrhage may lead to diverse neurological symptoms and findings. Transient ischemic attack and thrombotic stroke are the most common symptoms in polycythemia vera. Besides thrombosis and hemorrage, transformation to acute leukemia can cause neurological symptoms and findings. Transient ischemic attack, thrombotic stroke and specifically hemorrage can give rise to neurological symptoms similar to MPN in essential thrombocytosis. Extramedullary hematopoiesis refers to hematopoietic centers arise in organ/tissues other than bone marrow in myelofibrosis. Extramedullar hematopoietic centers may cause intracranial involvement, spinal cord compression, seizures and hydrocephalia. Though rare, extramedullary hematopoiesis can be detected in cranial/spinal meninges, paraspinal tissue and intracerebral regions. Extramedullary hematopoiesis has been reported in peripheral neurons, choroid plexus, pituitary, orbits, orbital and lacrimal fossa and in sphenoidal sinuses.
