Respiratory Epithelial Adenomatoid Hamartoma at an Unusual Location: A Case Report and Literature Review.

Respiratory epithelial adenomatoid hamartoma (REAH) in the head and neck is a rare benign lesion containing glandular tissue covered with ciliated respiratory epithelium. In the head and neck, REAH of the nasal cavity, paranasal sinuses, and nasopharynx have been reported in literature. Due to rareness of REAH and insufficient knowledge of its imaging features, the diagnosis can be challenging when we encounter a non-specific cystic mass at an uncommon site in the head or neck. Here, we report the case of a pathologically confirmed REAH showing a cystic mass centered at the buccal space (retromaxillary fat pad) with CT and MRI findings.

Iron Rim Lesions as a Specific and Prognostic Biomarker of Multiple Sclerosis: 3T-Based Susceptibility-Weighted Imaging.

This study aimed to identify the clinical significance of iron rim lesions (IRLs) in distinguishing multiple sclerosis (MS) from other central nervous system (CNS) demyelinating diseases, determine the relationship between IRLs and disease severity, and understand the long-term dynamic changes in IRLs in MS. We retrospectively evaluated 76 patients with CNS demyelinating diseases. CNS demyelinating diseases were classified into three groups: MS (n = 30), neuromyelitis optica spectrum disorder (n = 23), and other CNS demyelinating diseases (n = 23). MRI images were obtained using conventional 3T MRI including susceptibility-weighted imaging. Sixteen of 76 patients (21.1%) had IRLs. Of the 16 patients with IRLs, 14 were in the MS group (87.5%), indicating that IRLs were significantly specific for MS. In the MS group, patients with IRLs had a significantly higher number of total WMLs, experienced more frequent recurrence, and were treated more with second-line immunosuppressive agents than were patients without IRLs. In addition to IRLs, T1-blackhole lesions were observed more frequently in the MS group than in the other groups. IRLs are specific for MS and could represent a reliable imaging biomarker to improve the diagnosis of MS. Additionally, the presence of IRLs seems to reflect more severe disease progression in MS.

Primary Central Nervous System Involvement in Peripheral T-Cell Lymphoma: A Case Report.

Primary central nervous system T-cell lymphoma (PCNSTL) is an extremely rare type of brain tumor. There are only few reports on the imaging findings of patients with PCNSTL. Herein, we report the imaging findings of a patient with peripheral T-cell lymphoma-not otherwise specified that presented with numerous small nodular and patchy strongly enhancing lesions on MRI.

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia: A case report.

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a rare neurodegenerative disorder characterized by cerebral white matter abnormalities, myelin loss, and axonal swellings. ALSP is caused by mutations in colony stimulating factor 1 receptor gene. We report an ASLP patient with asymptomatic intracranial calcifications distributed in white matter found incidentally in a health screening.

Can clinical and MRI findings predict the prognosis of variant and classical type of posterior reversible encephalopathy syndrome (PRES)?

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is characterized by clinical symptoms that are associated with bilateral and symmetric vasogenic edema in the parietal and occipital lobes. However, this is rarely present with predominant involvement of the brain stem and cerebellum (variant). PURPOSE: To evaluate which clinical or magnetic resonance imaging (MRI) findings can help to predict the prognosis of variant and classical type of PRES and whether or not there is difference between two types of PRES. MATERIAL AND METHODS: We retrospectively evaluated MRI and clinical findings from 49 patients with PRES. These patients were divided into two groups. In group I, patients had atypical distribution of lesions. In group II, patients had typical distribution of lesions. Follow-up MRI was performed on 26 patients. We assessed the MRI features, clinical data, and the patients' outcomes. RESULTS: The mean blood pressure (BP) was significantly higher in group I (195.52/121.09 mmHg and 156.78/99.53 mmHg for groups I and II, respectively). The other factors assessed were not significantly different between the two groups. Lesions in 24 of 26 patients reversed upon follow-up. Sequelae were observed in 11 patients (group I, 7; group II, 4). However, there were no significant differences between the two groups. Except for those patients who died, seven of the nine patients with sequelae upon follow-up imaging had hemorrhage or irreversibility of lesions. CONCLUSION: Even though BP influences the involvement of the brain stem, involvement of the brain stem is not influential on the prognosis. It seems that the influential factor to prognosis is the reversibility of lesions and hemorrhage.

Gene expression profiles in genetically different mice infected with Toxoplasma gondii: ALDH1A2, BEX2, EGR2, CCL3 and PLAU.

Toxoplasma gondii can modulate host cell gene expression; however, determining gene expression levels in intermediate hosts after T. gondii infection is not known much. We selected 5 genes (ALDH1A2, BEX2, CCL3, EGR2 and PLAU) and compared the mRNA expression levels in the spleen, liver, lung and small intestine of genetically different mice infected with T. gondii. ALDH1A2 mRNA expressions of both mouse strains were markedly increased at day 1-4 postinfection (PI) and then decreased, and its expressions in the spleen and lung were significantly higher in C57BL/6 mice than those of BALB/c mice. BEX2 and CCR3 mRNA expressions of both mouse strains were significantly increased from day 7 PI and peaked at day 15-30 PI (P<0.05), especially high in the spleen liver or small intestine of C57BL/6 mice. EGR2 and PLAU mRNA expressions of both mouse strains were significantly increased after infection, especially high in the spleen and liver. However, their expression patterns were varied depending on the tissue and mouse strain. Taken together, T. gondii-susceptible C57BL/6 mice expressed higher levels of these 5 genes than did T. gondii-resistant BALB/c mice, particularly in the spleen and liver. And ALDH1A2 and PLAU expressions were increased acutely, whereas BEX2, CCL3 and EGR2 expressions were increased lately. Thus, these demonstrate that host genetic factors exert a strong impact on the expression of these 5 genes and their expression patterns were varied depending on the gene or tissue.

Diffusion MR imaging of postoperative bilateral acute ischemic optic neuropathy.

A 57-year-old woman experienced bilateral acute ischemic optic neuropathy after spine surgery. Routine MR imaging sequence, T2-weighted image, showed subtle high signal intensity on bilateral optic nerves. A contrast-enhanced T1 weighted image showed enhancement along the bilateral optic nerve sheath. Moreover, diffusion-weighted image (DWI) and an apparent diffusion coefficient map showed markedly restricted diffusion on bilateral optic nerves. Although MR findings of T2-weighted and contrast enhanced T1-weighted images may be nonspecific, the DWI finding of cytotoxic edema of bilateral optic nerves will be helpful for the diagnosis of acute ischemic optic neuropathy after spine surgery.

Reversible inferior colliculus lesion in metronidazole-induced encephalopathy: magnetic resonance findings on diffusion-weighted and fluid attenuated inversion recovery imaging.

OBJECTIVE: This is to present reversible inferior colliculus lesions in metronidazole-induced encephalopathy, to focus on the diffusion-weighted imaging (DWI) and fluid attenuated inversion recovery (FLAIR) imaging. MATERIALS AND METHODS: From November 2005 to September 2007, 8 patients (5 men and 3 women) were diagnosed as having metronidazole-induced encephalopathy (age range; 43-78 years). They had been taking metronidazole (total dosage, 45-120 g; duration, 30 days to 2 months) to treat the infection in various organs. Initial brain magnetic resonance imaging (MRI) were obtained after the hospitalization, including DWI (8/8), apparent diffusion coefficient (ADC) map (4/8), FLAIR (7/8), and T2-weighted image (8/8). Follow-up MRIs were performed on 5 patients from third to 14th days after discontinuation of metronidazole administration. Findings of initial and follow-up MRIs were retrospectively evaluated by 2 neuroradiologists by consensus, to analyze the presence of abnormal signal intensities, their locations, and signal changes on follow-up images. RESULTS: Initial MRIs showed abnormal high signal intensities on DWI and FLAIR (or T2-weighted image) at the dentate nucleus (8/8), inferior colliculus (6/8), corpus callosum (2/8), pons (2/8), medulla (1/8), and bilateral cerebral white matter (1/8). High-signal intensity lesions on DWI tended to show low signal intensity on ADC map (3/4), but in one patient, high signal intensity was shown at bilateral dentate nuclei on not only DWI but also ADC map. All the lesions in dentate, inferior colliculus, pons, and medullas had been resolved completely on follow-up MRIs in 5 patients, but in 1 patient of them, corpus callosal lesion persisted. CONCLUSIONS: Reversible inferior colliculus lesions could be considered as the characteristic for metronidazole-induced encephalopathy, next to the dentate nucleus involvement.

Lymphocytic hypophysitis with diabetes insipidus: improvement by methylprednisolone pulse therapy.

Lymphocytic hypophysitis is a rare inflammatory disorder in the pituitary gland. The lesion is usually confined to the adenohypophysis. Although the involvement of the posterior pituitary gland or the stalk is rare, such patients with diabetes insipidus have been reported. Surgery has been used to make the definitive diagnosis. Recent studies suggest, however, that the pathologic diagnosis may not be necessary always. We reported a case of Lymphocytic hypophysitis managed by methylprednisolone pulse therapy. A 50-year-old premenopausal woman with Lymphocytic hypophysitis and diabetes insipidus was treated with methylprednisolone pulse therapy. Her adenopituitary lesion disappeared and the diabetes insipidus resolved. The optimal management for patients with lymphocytic hypophysitis may be the high index of the suspicion prior to the extensive surgical resection. In addition, methylprednisolone pulse therapy may improve the clinical and MRI findings.

Chronic cerebral paragonimiasis combined with aneurysmal subarachnoid hemorrhage.

A 67-year-old Korean woman attended our hospital complaining of a severe headache. A brain computed tomography scan showed conglomerated, high-density, calcified nodules in the left temporo-occipito-parietal area and high-density subarachnoid hemorrhage in the basal cisterns. Magnetic resonance imaging of the brain shows multiple conglomerated iso- or low-signal intensity round nodules with peripheral rim enhancement. She underwent craniotomies to clip the aneurysm and remove the calcified masses. Paragonimus westermani eggs were identified in the calcified necrotic lesions. Results of parasitic examinations on the sputum and an enzyme-linked immunosorbent assay for P. westermani were all negative. The patient presented with headache and dizziness that had occurred for more than 30 years. She had not eaten freshwater crayfish or crabs. However, she had sometimes prepared raw crabs for several decades. Overall, this case was diagnosed as chronic cerebral paragonimiasis, in which she may have been infected through the contamination of utensils during the preparation of the second intermediate hosts, combined with a cerebral hemorrhage.