Diffuse Large B-Cell Lymphoma Transformed from a Rectal Mucosa-Associated Lymphoid Tissue Lymphoma / 이화의대지

Primary rectal lymphoma is a rare disease among the gastrointestinal (GI) lymphoma. In particular, diffuse large B-cell lymphoma (DLBCL) transformed from mucosa-associated lymphoid tissue (MALT) lymphoma is often the primary type of GI lymphoma, mostly in stomach or duodenum, but has never been reported in rectum. Here we report an unusual case in which a 75-year-old male patient diagnosed with DLBCL transformed from MALT lymphoma in the rectum. The patient was diagnosed as rectal DLBCL transformed from MALT lymphoma as Lugano stage II2 and was treated with chemotherapy (R-CHOP) with CD-20 monoclonal antibody (rituxaimb). Complete remission of multiple lymphadenopathy and mass forming ulcer of the rectum was achieved after 6 cycles of R-CHOP. He has been free from disease for 12 months.

Epileptogenic Properties of Balloon Cells in Cortical Tubers of Tuberous Sclerosis: Upregulation of Drug Resistance Proteins

OBJECTIVES: Balloon cells and dysplastic neurons are histopathological hallmarks of the cortical tubers of tuberous sclerosis complex (TSC) and focal cortical dysplasia (FCD) of the Taylor type. They are believed to be the epileptogenic substrate and cause therapeutic drug resistant epilepsy in man. P-glycoprotein (P-gp) is the product of multidrug resistance gene (MDR1), and it maintains intracellular drug concentration at a relatively low level. The authors investigated expression of P-gp in balloon cells and dysplastic neurons of cortical tubers in patients with TSC. METHODS: An immunohistochemical study using the primary antibody for P-gp, as an indicative of drug resistance, was performed in the cortical tuber tissues in two patients of surgical resection for epilepsy and six autopsy cases. RESULTS: Balloon cells of each lesion showed different intensity and number in P-gp immunopositivity. P-gp immunopositivity in balloon cells were 28.2%, and dysplastic neurons were 22.7%. These immunoreactivities were more prominent in balloon cells distributed in the subpial region than deeper region of the cortical tubers. Capillary endothelial cells within the cortical tubers also showed P-gp immunopositivity. CONCLUSION: In this study, the drug resistance protein P-glycoprotein in balloon cells and dysplastic neurons might explain medically refractory epilepsy in TSC.

A Case of Neonatal Hypoxic Ischemic Encephalopathy caused by Amniotic Fluid Embolism / 대한주산의학회잡지

Amniotic fluid embolism, one of the leading causes of maternal death, is a rare event, however, it can cause maternal death and neonatal morbidity when it unrecognized and untreated effectively. Its pathogenesis is unclear and clinical presentations are variable without standardized means of confirming diagnosis. We experienced one case of neonatal hypoxic ischemic encephalopathy possibly due to maternal amniotic fluid embolism, which was diagnosed by brain MRI, EEG and maternal uterine pathology. We report this case with a brief review of literatures.

Neurofilament Protein Subtype Expression in Neuronal Migration Disorders

BACKGROUND: Neuronal migration disorder (NMD) is one of the causes of medically intractable epilepsy. As neurosurgical treatments for medically intractable epilepsy have expanded recently, precise histopathologic diagnosis is required. Histopathologic grading of NMD is important due to its association with neocortical development and expectation of prognosis. Many studies revealed abnormalities of neuronal cytoskeletal protein in abnormal neuronal cells of NMD. METHODS: We performed immunohistochemical staining for neurofilament protein (NF) subtypes, one of the neuronal cytoskeletal proteins, and investigated the staining pattern of specific cells in each grade of NMD. RESULTS: NF-L was more intensely labeled in perikarya, dendrites, and axons of normal or small sized dysplastic neurons, cytomegalic neurons, and balloon cells than of normal-looking neurons. Furthermore, positive reaction was more intense in high-grade lesion. NF-H and NF-M were mainly positive in the axons of gray and white matter and weakly positive in a few cytomegalic neurons and some balloon cells. CONCLUSION: NF-L is a better marker than NF-H and NF-M for the detection of normal or small sized dysplastic neurons, cytomegalic neurons, and balloon cells and for grading of NMD.

Clonal Analysis of Neurofibroma by PCR Amplification of HUMARA Gene

BACKGROUND: While neurofibromas have generally been regarded as polyclonal hyperplastic lesions, it remains unclear whether the tumor is a true neoplasm or a hyperplastic lesion. METHODS: Determination of clonality by X chromosome inactivation pattern was investigated in twenty-one cases of neurofibroma employing enzyme digestion and PCR of the HUMARA gene. The histological, immunohistochemical, and ultrastructural characteristics of the tumors were also examined. RESULTS: Immunohistochemically, most of the tumor cells showed vimentin and S-100 protein positivity. Axons were demonstrated by neurofilament protein positivity and were seen mainly at the periphery and rarely in the central portion of the tumor. Ultrastructurally, the tumors were composed of a variety of cell types: perineurial cells, Schwann cells, fibroblasts, and axons. X chromosome inactivation analysis was completed on thirteen out of fifteen cases in which DNA was successfully extracted. Of thirteen neurofibromas that were heterozygous at the HUMARA loci, eleven showed a polyclonal pattern. The remaining two cases were considered as indeterminate for clonality because of unequal band intensity and failure to obtain the normal control DNA. CONCLUSION: The results from this study suggest that neurofibromas are polyclonal in origin and might be a neoplastic lesion comprising non-neoplastic cells among constituent components.