multiple myeloma ( mm ) and non - hodgkin s lymphoma ( nhl ) are lymphoproliferative diseases . the occurrence of both mm and other b cell lymphoproliferative disorder in the same patient is very vare and only a few cases have been described previously . we report here a case of a patient who had both mm and nhl with iga lambda monoclonal gammopathy at the time of presentation and we discuss the possible pathogenetic mechanism of the two disorders . a 58-year - old man presented with lower extremity petechiae , melena and weight loss during the previous 1 year . on examination he appeared acutely ill and pale . complete blood count showed hemoglobin 8.3g / dl , protein 7.2g / dl , albumin 2.0g / dl , creatinine 0.9mg / dl . serum electrophoresis revealed a monoclonal peak in the gamma globulin region , identified iga lambda on immunoelectrophoresis . free lambda light chain was present in the urine as well ( 11mg / dl ) . serum igg was 333mg / dl , iga 5850mg / dl , igm 52mg / dl . bone marrow aspiration smears revealed 0.6% of plasmablasts and 21.8% of plasma cells and the histological examination demonstrated a diffuse infiltration of atypical plasma cells coexisting with localized collections of monotonous neoplastic lymphoid cells ( fig . 1 , 2 ) . surface and intracytoplasmic immunoglo bulin were evaluated by a direct immunofluo rescence method using goat - antihuman ig labeled with fitc . immunofluorescent studies revealed lymphoid populations with bright surfacefluorescence for iga lambda , as well as the presence of iga lambda in the cytoplasm of plasma cells . contrast enhanced small bowel radiography demonstrated only mucosal irregularities and luminal narrowing of the jejunum . abdominal ct scan with oral contrast revealed an irregular mass in the jejunum with multiple lymph node enlargement . exploratory laparotomy was performed , revealing anunresectable mass in the jejunum and a small amount of ascites . biopsy of mesenteric lymph node disclosed malignant lymphoma of diffuse small cell type ( fig . 4 ) , and its immunochemical studies showed diffuse positivity for pan - b marker . the iga lambda monoclonal protein has diminished and the patient s general condition has improved . patients with mm can present with a variable spectrum of clinical features and different stages of the disease . mm is a disease in which approximately 99% of patients have a monoclonal protein in the serum and/or urine . this has led to the prevailing concept that myeloma is monoclonal at the cellular level . although lymphomas are usually neoplasms of lymphatic tissues , substantial numbers of non - hodgkin s lymphoma arise in other tissue . al . found the incidence of bone marrow involvement in approximately 65% of non - hodgkin s lymphomas ( nhl ) at the time of diagnosis . in this case , the patient fulfilled criteria for mm with iga lambda monoclonal gammopathy and bone marrow plasmacytosis . in the bone marrow biopsy , there were localized collection of malignant lymphocytes in addition to the malignant plasma cells . the occurrence of both mm and nhl in our patient implies several possible pathogenetic mechanisms . a comparison of the immunologic phenotype of both mm and nhl in a patient is needed to reach meaningful conclusions . in our patient , where monoclonal ig synthesized by both cell types had the same type of light chains , we performed a study with anti - idiotype reagents ; idiotypic determinants expressed by serum and intracellular plasmacytic ig were detectable on the surface ig of lymphoma cells . these findings suggest the possibility that the lymphoma cells transformed into plasma cells . on the other hand , the development of high grade malignant lymphoma in patient with chronic lymphocytic leukemia was first reported by richter in 1928 and transformation to high grade lymphoma is now a well - known event in other low grade malignancies of the b cell lineage . this increased survival has permitted the development and improved the chance of observing transformation of mm to high grade malignant lymphoma . another possible mechanism is that both malignancies are different manifestation of original neoplastic clone . in 1982 , bryant et . al . , reported plasma cell myeloma in a patient with a cutaneous t - cell lymphoma . in 1986 , gran et . al . , described a patient with coincident mm and nhl with 2 serum monoclonal immunoglobulin . they suggest that the rare association of two diseases represents different manifestations of a unique clonal disorder which affects the b cell precursor . although it would be rare , a possibility of independent of two infrequent malignancies at one time exists . in terms of patient management , treatment must be directed to the more life - threatening condition . in our case , this case offers additional support to the theory of malignant transformation of mm and nhl . opportunities to study and understand the unique natural history and evolutional dynamics for this transformation are rare . we would recommend further multicenter comparisons of slimilar cases in a broad effort to better define this complicated disease process .
a rare case of coexisting multiple myeloma and non - hodgkin s lymphoma at the time of diagnosis is presented . 
 the patient presented with petechiae , melena and weight loss . 
 iga lambda monoclonal gammopathy in the serum and free lambda chain in urine were documented . 
 bone marrow biopsy demonstrated an interstitial infiltration of neoplastic plasma cells coexisting with localized collection of noeplastic lymphoid cells composed of monotonous small lymphocytes with occasional cleaved nuclei . 
 immunophenotype of plasma cell was iga lambda . 
 the patient also had a jejunal mass , with biopsy proven malignant lymphoma , diffuse small cleaved cell type . 
 the tumor was diffusely positive for pan - b marker . 
 after chemotherapy , the iga lambda monoclonal protein decreased and the patient improved . 
 this case suggest , that the seound b - cell neoplasm may have evolved by transformation of an original neoplastic clone , or that malignant tumors may be polyclonal at onset . 
 definitive diagnosis and staging of each disorder is important for proper management .