IJCRI – International Journal of Case Reports and Images, Vol. 4 No. 9, September 2013. ISSN – [0976-3198] IJCRI 2013;4(9):498–501. www.ijcasereportsandimages.com Datta et al. 498 CASE REPORT OPEN ACCESS Primary cerebellar B cell lymphoma: A case report Anupam Datta, Arunima Gupta, Krishnangshu Bhanja Choudhury, Aruj Dhyani, Anup Majumdar AbstrAct Introduction: Primary central nervous system lymphoma (PcNsL) is usually a diffuse large b cell non-Hodgkin lymphoma that originates in the brain, spinal cord, leptomeninges or eyes. Primary central nervous system lymphoma is a rare malignant tumor comprising less than 3% of all primary brain tumors. the PcNsL in immunocompetent patients is most commonly supratentorial, found adjacent to the ventricular surfaces and in deep white matter and subcortical structures, such as the basal ganglia, thalamus and corpus callosum. the lesion is single in 60–70% of patients. Lesions are located in the hemispheres (38%), thalamus/basal ganglia (16%), corpus callosum (14%), periventricular region (12%) and cerebellum (9%). Herein, we report an extremely rare case of a primary cNs b cell lymphoma involving cerebellum. case report: A 55-year-old female was presented with vomiting, ataxia and disorientation. t2- Anupam Datta 1 , Arunima Gupta 1 , Krishnangshu Bhanja Choudhury 2 , Aruj Dhyani 1 , Anup Majumdar 3 Affiliations: 1 Post Graduate trainee, Radiotherapy, Junior Resident, Department of Radiotherapy, Institute of Post graduate Medical Education and Research, Kolkata-700020, West Bengal, India; 2 MD, Radiotherapy. RMO-cum-Clinical tutor, Department of Radiotherapy, R.G.Kar Medical College and Hospital, Kolkata -700004, West Bengal, India; 3 MD, Radiotherapy, Professor and Head, Department of Radio- therapy, Institute of Post graduate Medical Education and Research, Kolkata-700020, West Bengal, India. Corresponding Author: Krishnangshu Bhanja Choudhury, Designation: RMO-cum-Clinical tutor, Department of Ra- diotherapy, R.G.Kar Medical College and Hospital, Kolk- ata -700004, West Bengal, India; Address: C-11/4, Green Tower, Golf Green, Kolkata -700095, West Bengal; Ph: +91- 9830932869; E-mail: krishnangshuchoudhury@gmail.com Received: 30 July 2012 Accepted: 06 March 2013 Published: 01 September 2013 weighted axial, t1-weighted and gadolinium- enhanced t1-weighted axial magnetic resonance imaging scans show a contrast enhancing mass with peritumoral edema in the right cerebellar hemisphere. Excision biopsy was suggestive of non-Hodgkin lymphoma. Diagnosis was confirmed with immunohistochemistry favoring non-Hodgkin lymphoma of diffuse large b cell type. this patient received cytotoxic therapy with carmustine 200 mg IV 6 weekly 3 cycles followed by external beam radiation therapy 30 Gy. No recurrence was noticed in one year follow-up. conclusion: Primary b cell lymphoma limited to the cNs is exceedingly rare in the middle aged immunocompetent individual. Little is known regarding etiologic factors, optimal management and prognosis. Keywords: Non-Hodgkin lymphoma, carmustine, b-cell lymphoma, cerebellum ********* Datta A, Gupta A, Choudhury KB, Dhyani A, Majumdar A. Primary cerebellar B cell lymphoma: A case report. International Journal of Case Reports and Images 2013;4(9):498–501. ********* doi:10.5348/ijcri-2013-09-365-CR-9 INtroDuctIoN Primary central nervous system lymphoma (PCNSL) is usually a diffuse large B cell non-Hodgkin lymphoma that originates in the brain, spinal cord, leptomeninges or eyes. The PCNSL is a rare malignant tumor representing 3% of intracranial neoplasms and 4–6% of extra nodal lymphomas with a yearly incidence of 0.5 case per 100,000 people and with a median survival, if untreated, of 1.5–3.3