Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 12 3 2018 07 04 168 173 EN Kalina Tumangelova-Yuzeir Laboratory of Clinical Immunology, University Hospital “St. Ivan Rilski”, Department of Clinical Laboratory and Clinical Immunology, Medical University of Sofia, Sofia, Bulgaria Ekaterina Ivanova-Todorova Laboratory of Clinical Immunology, University Hospital “St. Ivan Rilski”, Department of Clinical Laboratory and Clinical Immunology, Medical university of Sofia,Sofia, Bulgaria Emanuil Naydenov Clinic of Neurosurgery, University Hospital “St. Ivan Rilski”, Sofia, Bulgaria Tsvetelina Velikova Laboratory of Clinical Immunology, University Hospital “St. Ivan Rilski”, Department of Clinical Laboratory and Clinical Immunology, Medical University of Sofia, Sofia, Bulgaria Ekaterina Krasimirova Laboratory of Clinical Immunology, University Hospital “St. Ivan Rilski”, Department of Clinical Laboratory and Clinical Immunology, Medical University of Sofia, Sofia, Bulgaria Kalina Belemezova Tissue Bank “BulGen”, Sofia, Bulgaria Tihomir Dikov Laboratory of Hematopathology and Immunology, National Specialized Hospital for Active Treatment of Hematological Diseases, Sofia, Bulgaria Marin Penkov Department of CT and MRI, University Hospital “St. Ivan Rilski”, Sofia, Bulgaria Sevdalin Nachev Laboratory of Neuropathology, University Hospital “St. Ivan Rilski”, Sofia, Bulgaria Margarita Genova Laboratory of Hematopathology and Immunology, National Specialized Hospital for Active Treatment of Hematological Diseases, Sofia, Bulgaria Dobroslav Kyurkchiev Laboratory of Clinical Immunology, University Hospital “St. Ivan Rilski”, Department of Clinical Laboratory and Clinical Immunology, Medical University of Sofia, Sofia, Bulgaria 2016 07 23 2016 10 15 The case report presented here describes the culturing and characterization of mesenchymal stem cells (MSCs) isolated from a primary indolent B-cell lymphoma, located in the CNS of an immunocompetent patient. The presence of such cells in the tumor mass can further elucidate the pathogenesis of the disease and reveal possible future approaches for its treatment.  We present a case report of a 61-year-old immunocompetent woman who had an episode of confusion with numbness in the right leg and the right arm, slurred and dysarthric speech and urine incontinence. The peripheral blood tests were normal. The neurological examination demonstrated a latent hemi-paresis of the right side, aphasia, discrete hypertension and bradypsychia. The ophthalmologic examination revealed left quadranopsia. Computed tomography and magnetic resonance imaging of the brain showed a 3.5 × 2.9 cm infiltrative neoplastic lesion involving the left temporal parenchyma. The morphological features and the immunophenotyping of the lymphoid cell composition were consistent with low-grade (indolent) B-lymphocyte non-Hodgkin’s lymphoma of CNS. Cells, isolated from the resected tumor mass, were cultured in vitro in medium containing 10% fetal bovine serum (FBS) and characterized by their morphology, growth, phenotype, clonogenicity and osteogenic differentiation. It was apparent that the cultured cells isolated from the indolent B- cell lymphoma located in the CNS have the basic characteristics of mesenchymal stem cells. The presence of MSCs is described for the very first time in such type of tumor. The well-known immunosuppressive properties of the MSCs may represent another mechanism favouring the tumor growth.  https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/654 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/654/636