[Identification of etiological connections among virtually distinct diseases in a patient may be sometimes challenging. We report a unique case with two B cell malignancies and an inflammatory leukoencephalopathy. Three days prior to admission, the elderly male patient developed fatigue, headaches, recurrent vomiting, memory disturbances, depression and somnolence. Clinical, laboratory and imaging evaluations as well as post mortem histological studies were performed. Simultaneous presence of primary central nervous system B cell lymphoma, temporal lobe inflammatory leukoencephalopathy and multiple (smoldering) myeloma, was revealed by the detailed work up in the treatmentnaïve patient. Based on recent data from genomic studies, we propose that a sequential evolution of molecular pathology lead to the co-occurrence of multiple myeloma and primary central nervous system B cell lymphoma in this patient, and interpret the development of the temporal lobe leukoencephalopathy as a likely paraneoplastic complication of smoldering myeloma.]

[INTRODUCTION - Meningeal infiltration by multiple myeloma is rare. Its incidence among cases of multiple myeloma is 1%. CASE REPORT - Multiple myeloma was diagnosed in a 53-year-old woman in December 2014. After chemotherapy, the disease was treated with autologous bone marrow transplantation in June 2015. Remission was observed through two months, but in August the patient was hospitalized due to severe headache with neck stiffness. Meningitis or viral encephalitis were suspected following her investigation. She was taken to the Intensive Care Unit because of a progression to status epilepticus. The EEG-examination revealed generalized slow wave activity and a right temporal epileptiform focus manifesting rarely. Clinical brain death developed on the 17th day in hospital. DISCUSSION - Although meningeal infiltration is infrequent in multiple myeloma, the present case report draws attention to this possibility. ]

[We report a case of a 50-year-old male patient, in whom the coexistence of multiple myeloma and diffuse large B cell lymphoma was confirmed. In December 2007, the patient was admitted to the department of internal medicine with fatigue resulting from mild anemia. A tumor of the left testis was discovered, and after semicastration diffuse large B cell lymphoma was diagnosed by histopathological analysis (clinical stage: II/EB). Examination of the bone marrow revealed a plasmocytic infiltrate of 60%, while 36.1 g/l IgG-kappa paraprotein was found in the peripheric blood, fulfilling the diagnostic criteria of multiple myeloma (Durie-Salmon stage: I). The patient received six cycles of rituximab- CHOP-21 chemotherapy for diffuse large B cell lymphoma. Following a transient improvement, the multiple myeloma showed progression, therefore we switched to VTD protocol (bortezomib, thalidomid, dexamethason). The patient underwent high dose chemotherapy and autologous hematopoietic stem cell transplantation. Both hematologic diseases showed complete remission. Both tumour samples were tested for immunoglobulin heavy-chain rearrangement by polymerase chain reaction and DNA sequence analysis, according to which the possibility for clonal relationship between multiple myeloma and diffuse large B cell lymphoma could not be confirmed.]