primary hepatic lymphoma ( phl ) refers to tumor confined in the liver at the early stage of lymphoma without infiltration of other locations . phl is a rare disease , with an incidence of only 0.1% for malignant liver tumors . this disease also accounts for 0.4% of all primary extranodal lymphoma and 0.016% of all non - hodgkin 's lymphoma . phl of diffuse large b - cell lymphoma ( phl - dlbcl ) is more infrequent . hence , the condition is difficult to distinguish from primary liver cancer , liver metastases , granulomatous pseudotumor , and other diseases and is thus easily misdiagnosed . to improve clinicians ' understanding of this disease , the diagnosis and treatment course of a case of phl in our hospital were discussed in detail . a 61-year - old male was admitted because of  fatigue and abdominal distension for over 50 days . the patient presented with a 6  kg weight loss ( 12% ) and experienced fatigue and abdominal distension from an unknown cause since 50 days prior to admission . the patient showed no signs of skin pruritus or yellow discoloration of the skin or eyes . despite his symptoms , he was then admitted in a local hospital from june 6 to june 12 , 2014 because of fever . the patient suffered from chills and sweating , and his body temperature fluctuated at 37.438.9c . he was then treated with cefoperazone / sulbactam sodium for the inflammation , pantoprazole to relieve hyperacidity , and polyene phosphatidylcholine to protect the liver , all of which afforded the patient with no improvement of condition . the patient sought consultation in one of the top three local hospitals on june 19 . his signs and symptoms of fatigue , abdominal distension , and yellow urine aggravated , along with the decrease in urine amount . at the time , the patient presented with a urine output of less than 500  ml/24  h , with concurrent skin pruritus , icteric skin and sclerae , occasional cough , and severe bilateral lower extremities edema . he also experienced slight chest tightness and hence was admitted to the hospital . upon admission , routine blood examination obtained the following results : white blood cell count , 9.3  10/l ; neutrophil absolute value , 4.9  10/l ; hemoglobin , 128 g / l ; alt , 128  u / l ; ast , 109  u / l ; total bilirubin , 12.5  mol / l ; direct bilirubin , 2.7  mol / l ; indirect bilirubin , 125  mol / l ; hydroxybutyrate dehydrogenase , 1093  u / l ; lactate dehydrogenase , 1387 u / l ; and total bile acids ( tba ) , 2.461  mol / l . the liver fibrosis index is as follows : hyaluronic acid , 1162.2  g / l ; type iv collagen , 279.4  g / l ; type iii collagen , 659.8  g / l ; and laminin , 149  g / l . mol / l , whereas that of c - reactive protein was 136.4  mg / hepatitis b screening tested positive for three components : hbv - dna , 3.1e + 02  copy / ml . chest computed tomography ( ct ) scan revealed the following findings : ( 1 ) small fibrotic foci at the middle lobe of the right lung and lingular segment of the superior lobe of the left lung and ( 2 ) emphysema in the superior lobe of the right lung and calcified foci at the superior lobe of the left lung . no swollen lymph nodes were found by ultrasound on the bilateral neck , supraclavicular , subaxillary , and inguinal regions . abdominal ct ( july 11 , 2014 ) displayed ( 1 ) hepatosplenomegaly , ascites , patchy low - density shadows in the liver ( especially in the left liver ) , and multiple low - density lesions in the right lobe of liver ; ( 2 ) gallbladder wall thickening ; and ( 3 ) prostate calcification ( figure 1 ) . the patient was treated with entecavir dispersible tablet 0.5  mg qd , oral administration of antiviral drugs , and drugs for liver protection and diuresis . pathological examination showed the following results : heteromorphic lymphocytes were observed in the hepatic sinusoid and portal area . for immunohistochemistry , lca , cd20 , and bcl-6 were diffusely strongly positive ; cd79a and mum-1 were locally weakly positive ; the ki-67 labeling index was about 60% ; and ck , cd68 , cd34 , hepaar-1 , cd3 , cd43 , cd10 , and alk were negative ; hbs - ag and hbc - ag were negative ( figure 3 ) . bone marrow morphology and biopsy showed no signs of lymphoma infiltration . on the basis of clinical , laboratory , and pathological examinations , the patient was diagnosed with primary hepatic non - hodgkin 's lymphoma staged iva ( dlbcl , non - gcb ) , chronic viral hepatitis ( b ) , and decompensated cirrhosis . chop ( cyclophosphamide , doxorubicin , vincristine , and prednisone ) scheme chemotherapy was then initiated on july 17 with the following agents : ifo , 2  g ( days 1 and 8) ; thp , 60  mg ( day 1 ) ; dxm , 10  mg ( days 1 to 5 ) ; and vds , 4  mg ( days 1 , 8 , and 15 ) . the ct review after the first chemotherapy ( august 11 ) showed that the liver significantly decreased in size , and liver density became uniform ( figure 2 ) . the r - chop scheme was adopted for six cycles ( chop with rituximab injection , 500  mg [ day 0 ] ) ; the other drugs included were the same as those mentioned above ) . no new lesion was noted , and the patient has lived for nearly 2 years till now of disease - free - survival . primary hepatic lymphoma ( phl ) refers to the lesion only confined to the liver at the early stage of lymphoma . infiltrations of lymph nodes , spleen , bone marrow , and other organs must be excluded at the onset . the patient 's clinical characteristics include abdominal distension , fatigue , abnormal liver function , and progressive hepatomegaly . the involvement of other locations was excluded by superficial lymph node examination , bone marrow morphology and biopsy , and radiologic examinations . phl may occur at any age but more commonly in males of about 50 years old . the male - to - female ratio for the disease incidence is about 3  :  1 . however , primary liver non - hodgkin 's lymphoma is extremely rare , accounting for 0.4% of all primary extranodal lymphoma and 0.016% of all cases of non - hodgkin 's lymphoma . the etiology of phl is uncertain and may include virus infection ( hiv , aids , hbv , hcv , and ebv ) , autoimmune diseases , and immune inhibitor application . its mechanism potentially involves t lymphocyte loss of inherent immune surveillance and function after viral infection or application of immunosuppressive agents . most patients seek consultation because of fatigue , loss of appetite , night sweats , low - grade fever , and weight reduction . several patients suffer from hepatic encephalopathy early , resulting in coma and even death [ 2 , 4 ] . in our case , the patient experienced abdominal distension and fatigue and sustained low fever , hepatomegaly , and progressive increase of bilirubin , which were rapidly relieved by treatment . the patient 's clinical characteristics were consistent with that of primary hepatic non - hodgkin 's lymphoma . for laboratory indices , most phl patients show elevated alt and ast levels by two to three times of the normal value , which is also significantly increased with the increase in bilirubin and hdl . however , afp and cea levels are usually normal , in contrast to those in primary liver cancer and liver metastasis . some patients sustain diffuse liver lesions , displayed in radiologic examination as hepatomegaly without liver space - occupying lesion . the central mass mainly shows low - density shadows in ct and sometimes multilobar or patchy low - density shadows , which are peripherally intensified after enhancement . this result may be explained by the lesser vascularization of the lymphoma compared with other tumors , resulting in tissue necrosis during the disease process . the radiologic performance of the patient showed that the liver was obviously enlarged and the liver texture was not uniform , combined with patchy low - density shadows , which was consistent with literature reports [ 5 , 6 ] . most hepatic lymphomas are derived from b - lymphocyte cells , whereas the minority originates from t lymphocytes . phl patients with liver function abnormality , hepatomegaly , or space - occupying lesions but with normal afp and cea must be suspected of liver lymphoma . however , tissue necrosis is often associated with liver lymphoma ; hence , fine needle aspiration biopsy may provide false negative results . phl was often misdiagnosed as other conditions , such as embryonic sarcoma , inflammatory pseudotumor , or granulomatous hepatitis . cellular immunology , gene rearrangement , cell genetics , and molecular biology related to phl should be explored to assist diagnosis and determine prognosis . however , with the continuous development of chemotherapeutic regimens , especially the application of targeted therapeutic drugs , chemotherapy or combined local radiotherapy has become the first - line treatment of phl . our patient was diagnosed with phl - dlbcl . the single - course treatment with chop combined with rituximab was significant . the liver was significantly reduced in size , and the low - density lesions were significantly decreased . in a previous study , the follow - up visits of 24 phl cases after 20 years by the anderson cancer center in the united states revealed a complete remission rate of 85% through chemotherapy and an event - free five - year survival of 70% . a considerable number of prospective , randomized controlled clinical trials are lacking and must be further conducted .