A case of diffuse-type primary hepatic lymphoma mimicking diffuse hepatocellular carcinoma.

Primary hepatic lymphoma (PHL) is a very rare disease, especially in the diffuse type. We report a case of a middle-aged man with hepatitis C virus infection who developed diffuse-type PHL mimicking diffuse hepatocellular carcinoma (HCC). Contrast-enhanced computed tomography (CT) and magnetic resonance imaging showed diffusely infiltrated hypovascular lesions throughout the liver, but no intrahepatic portal venous thrombus was observed. Diffusion-weighted imaging and (18)F-FDG positron emission tomography/CT, respectively, showed a very low apparent diffusion coefficient value and high FDG uptake. These findings were more suggestive of diffuse-type PHL than diffuse HCC. Liver biopsy examination confirmed a diagnosis of diffuse large B-cell lymphoma. Systemic staging revealed no evidence of nodal or bone marrow involvement, so PHL was diagnosed. The patient was treated with chemotherapy and achieved complete remission. We suggest that a combination of image modalities may enable differentiation of diffuse-type PHL from diffuse HCC.

[A case of co-existent disseminated Mycobacterium avium infection and non-Hodgkin's lymphoma].

A 76-year-old man was admitted to our hospital with dyspnea. Chest CT revealed bronchial stenosis caused by mediastinal lymphadenopathy. An FDG-PET scan showed increased FDG uptake in the mediastinal lymph nodes, lumbar vertebrae and left ilium. Neither the first biopsy specimen from the left ilium nor the endobronchial lesion showed malignant cells, but both were positive on acid-fast bacillus staining. Genetic testing found the Mycobacterium avium (MAC) gene. Therefore, we diagnosed disseminated MAC infection, and started antibiotic therapy. However, he did not respond to the therapy, and his bronchial stenosis worsened. We performed a biopsy of the newly-appearing supraclavicular lymph node, and of the left ilium again, and confirmed a new diagnosis; diffuse large B cell lymphoma, coexistent with disseminated MAC infection. This case suggests not only the simultaneous occurrence of disseminated MAC infection and diffuse large B cell lymphoma, but also the coexistence of both diseases within the same organs, and that there may be some relationship between the two diseases.

Enteropathy-type T-cell lymphoma showing repeated small bowel rupture and refractoriness to chemotherapy: a case report.

The majority of gastrointestinal lymphomas arise in the stomach, whereas lymphomas occurring in the intestine are relatively rare and a limited fraction of them show the T-cell phenotype with clinical manifestations similar to de novo celiac disease. Enteropathy-type T-cell lymphoma is extremely rare in Japan, presumably owing to the very low incidence of celiac disease among the Japanese population. Here, we report a 66-year-old Japanese male who was diagnosed as having enteropathy-type T-cell lymphoma preceded by diarrhea and intermittent bloody stool for over 1 year. He was admitted to our hospital as an emergency case because of panperitonitis due to intestinal perforation. After immediate partial small-bowel resection, cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy was started. However, the disease was highly refractory and was exacerbated with leukemic transformation. Subsequent salvage chemotherapy could not be completed because of the formation of spontaneous jejuno-abdominal fistula, followed by fatal septic shock. Particular attention should be paid to the peculiar clinical manifestations of enteropathy-type T-cell lymphoma such as malnutrition, frequent intestinal perforation and refractoriness to chemotherapy.