Diffusion tensor images and magnetic resonance spectroscopy in primary central nervous system T-cell lymphoma: a case report.

PURPOSE: Primary central nervous system lymphoma (PCNSL) is rare and usually B cell in origin. T-cell lymphoma constitutes only 1.8% to 4.6% of the PCNSL, and may present as solitary or multiple homogeneous enhanced lesions. There have been few reports showing unusual leukoencephalopathy in PCNSL, which may be confused with other white matter diseases including multiple sclerosis and acute disseminated encephalomyelitis. CASE REPORT: We reported a patient with T-cell PCNSL who presented a progressive dull response and extrapyramidal symptoms. Brain magnetic resonance imaging showed multiple focal leukoencephalopathy. Diffusion weighted imaging demonstrated hyper-intensity lesions and apparent diffusion coefficient images showed hypo-intensity lesions. Diffuse tensor images showed decreased fractional anisotropy. Pathology examination finally confirmed T-cell lymphoma. CONCLUSION: Although recent development of neuro-imaging studies, the diagnosis of PCNSL still await further pathological confirmation in some occasions.

Clinical phenotype, prognosis and mitochondrial DNA mutation load in mitochondrial encephalomyopathies.

We studied 42 individuals, including 8 patients with either complete or partial syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), 8 patients with either complete or partial syndrome of myoclonic epilepsy with ragged-red fibers (MERRF) and 26 maternal family members who carried either the A3243G or A8344G mutation of mitochondrial DNA (mtDNA). Clinical manifestations and prognosis were followed up in the patients harboring the A3243G or A8344G mutation. The relationship between clinical features and proportions of mutant mtDNAs in muscle biopsies, blood cells and/or hair follicles was studied. In the 8 regularly followed patients with the A3243G mutation, 4 died within 1 month to 7 years due to status epilepticus and/or recurrent stroke-like episodes. Two patients developed marked mental deterioration and 2 remained stationary. All of the patients harboring the A8344G mutation were stable or deteriorated slightly, except for 1 patient who died due to brain herniation after putaminal hemorrhage. The A3243G and A8344G mtDNA mutations were heteroplasmic in the muscle biopsies, blood cells and hair follicles of both the probands and their maternal family members. The mean proportion of A3243G mutant mtDNA in the muscle biopsies of the patients with MELAS syndrome (68.5 +/- 21.3%, range 33-92%) was significantly higher than that of the asymptomatic family members (37.1 +/- 12.6%, range 0-51%). The average proportions of A8344G mutant mtDNA in the muscle biopsies (90.1 +/- 3.9%, range 89-95%) and hair follicles (93.9 +/- 6.4%, range 84-99%) of the patients with MERRF syndrome were also significantly higher than those of the asymptomatic family members (muscle: 40.3 +/- 39.5%, range 1-80%; hair follicles: 51.0 +/- 44.5%, range 0.1-82%). We concluded that measurement of the proportion of mutant mtDNA in muscle biopsies may provide useful information in the identification of symptomatic patients with mitochondrial encephalomyopathies. For patients with the A3243G mutation, the prognosis was related to status epilepticus and the number of recurrent stroke-like episodes and was much worse than for patients with the A8344G mutation of mtDNA, who had stable or slowly deteriorating clinical courses.