An Aggressive Natural Killer Cell Lymphoma Presenting as Acute Liver Failure with Ascites / 대한내과학회지

Acute liver failure (ALF) is a medical emergency triggering an urgent need for liver transplantation. The most common causes of ALF are drug- and virus-associated hepatitis, but hematological malignancies such as an aggressive natural killer cell lymphoma (ANKL) can uncommonly cause ALF. A 50 year-old male presented with ascites, jaundice, and encephalopathy. The ascitic fluid had a serum-ascites albumin gradient of 0.3 g/L, and contained atypical lymphocytes, which were positive for CD3. Computed tomography revealed mild hepatomegaly and multiple nodules in both lobes of the liver. A liver biopsy showed that the liver parenchyma had been infiltrated by malignant lymphoid cells, and exhibited marked sinusoidal dilatation. Immunohistochemically, the lymphoid cells were positive for CD3, CD56, and Epstein-Barr virus-encoded small RNA. The patient was diagnosed with ANKL causing ALF, and died on hospital day 12. This case shows that infiltration of the liver with ANKL can (rarely) cause ALF.

Two Cases of Treatment with Intrathecal Rituximab for Primary Central Nervous System Lymphoma / 대한내과학회지

Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin's lymphoma (NHL), usually composed of diffuse large B-cells. Although rituximab is known for its curative effect on B-cell NHL, data on the use of intrathecal rituximab for PCNSL are limited. In this report, we present two patients showing relapsed PCNSL with lymphomatous meningitis. Both patients were refractory to conventional methotrexate-based intrathecal chemotherapy. However, after intrathecal rituximab with or without conventional intrathecal chemotherapy, both patients showed stable disease on magnetic resonance brain imaging and cerebrospinal fluid analysis. There were no serious adverse events during each of 3 and 6 cycles with intrathecal rituximab immunotherapy.

A Case of Basaloid Squamous Cell Carcinoma of Rectosigmoid Colon / 대한소화기학회지

Basaloid squamous cell carcinoma is a rare and aggressive variant of squamous cell carcinoma, which mostly occurs in the upper aerodigestive tracts. Basaloid squamous cell carcinoma also typically arises in the anal canal, but is extremely rare in the lower gastrointestinal tract. A 70-year-old man presented with loose stool and intermittent hematochezia 2 months ago. Colonoscopy showed an ulceroinfiltrative mass on the rectosigmoid colon from 16 cm to 18 cm above the anal verge. Conventional colonoscope could not pass through the lesion but it was possible with pediatric colonoscope. Abdominal CT scan showed 1.6 cm sized wall thickening with circumferential luminal narrowing in the rectosigmoid colon and multiple ill-defined low density masses in both lobes of the liver. Therefore, colon cancer with liver metastasis was suspected. However, basaloid cells were noted on histologic examination, and they were weakly positive for synaptophysin on immunohistochemical study. After palliative lower anterior resection, histologic examination of the resected specimen revealed basaloid differentiation with keratin pearls, and tumor cells were positively stained with high molecular weighted cytokeratin (34BE12) and CK 5/6. Thus, the patient was finally diagnosed with basaloid squamous cell carcinoma of rectosigmoid colon with distant metastases.