Retained intraocular foreign body simulating choroidal melanoma. A report of two cases

Many different lesions can be difficult to distinguish from malignant melanomas of the choroid. With the use of modern diagnostic facilities the misdiagnosis rate has been greatly reduced. In a recent report from the Collaborative Ocular Melanoma Study Group the incidence of misdiagnosis was only 0.48%. The presence of a retained intraocular foreign body presenting as a raised pigmented choroidal mass similar to a uveal melanoma is rare. We report two cases in which retained intraocular foreign bodies presented clinically as raised pigmented intraocular lesions. Retained intraocular foreign bodies should be considered in the differential diagnosis of ocular tumours, especially if there are any atypical features.     

Choroidal hemangioma: MR findings and differentiation from uveal melanoma

Transgenic mice (T26) bearing the envelope, regulatory, and accessory genes of HIV- I develop renal disease resembling human HIV-associated nephropathy (HIVAN). Effects of vehicle (VEH) and the angiotensin-converting enzyme inhibitor captopril (CAP) were examined in wild-type (WT) or T26 mice treated from 7 to 100 d of age. Mortality was lower in CAP T26 mice (30 mg/kg: 8%; 100 mg/kg: 12%) than VEH T26 mice (52%). The urinary protein/creatinine ratio was increased in VEH T26 mice (19.5+/-7.60) versus WT mice (6.1+/-0.83), but not in low-dose (7.3+/-0.94) or high-dose (8.2+/-1.02) CAP T26 mice. Blood urea nitrogen was higher in VEH T26 mice (52+/-16.2 mg/dl) than VEH WT mice (24+/-0.8). Blood urea nitrogen was also elevated in CAP WT (high dose: 43+/-2.1 mg/dl) and T26 mice (high dose: 42+/-2.4 mg/dl). Glomerular injury was higher in VEH T26 mice (6.8+/-0.58) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 1.1+/-0.17; high dose: 0.7+/-0.13). Tubulointerstitial injury was also greater in VEH T26 mice (1.1+/-0.10) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 0.4+/-0.10; high dose: 0.3+/-0.10). These data validate recent nonrandomized studies of captopril in HIV-infected patients, and suggest that an angiotensin-converting enzyme substrate is an important mediator in HIVAN. A randomized placebo-controlled trial of captopril in HIVAN may be warranted.     

Bone SPECT imaging of vertebral hemangioma correlation with MR imaging and symptoms

To evaluate the bone SPECT findings of vertebral hemangioma and their relationship to symptoms and MRI findings, the authors reviewed planar and SPECT bone scans and MR images of 15 vertebral hemangioma in 10 patients. All planar bone scan images demonstrated normal findings, except one, SPECT images demonstrated normal findings in 11 vertebral hemangioma less than 3 cm in diameter. Three of four vertebral hemangioma that were 3 cm or larger showed abnormally increased or decreased uptake on SPECT images. There was a disparity between SPECT imaging and MRI.     

MR imaging techniques for soft-tissue lesions

MR imaging is the technique of choice for detection, characterization, and staging of soft-tissue neoplasms. MR examinations need to be tailored to each patient based upon the patient's size and anatomic region of interest so that optimal information is obtained. Technique is critical. Proper positioning to allow patient comfort and reduce motion artifacts is essential. Selection of the appropriate coils, image planes, and optimal pulse sequences to identify and determine the extent of lesions is critical for therapy planning.     

Varix of the vortex vein ampulla simulating choroidal melanoma: report of four cases

Increasing evidence demonstrates that ultraviolet A radiation (UVA) contributes to photoaging, which results in the accumulation of massive amounts of abnormal elastic material in the dermis of photoaged skin. To study UVA-induced photoaging in an in vivo system, we utilized a line of transgenic mice containing the human elastin promoter linked to a chloramphenicol acetyl transferase reporter gene. Our prior work demonstrates promoter activation in response to ultraviolet B radiation (UVB), UVA, and psoralen plus ultraviolet A radiation in the skin of these mice. The addition of psoralen (8-MOP) prior to administration of UVA results in substantial increases in promoter activation, as compared with UVA alone. To demonstrate the utility of these mice as a model of UVA-induced photodamage, we administered four lotions to the skin of our transgenic mice that included: a sunscreen containing octyl methoxycinnamate and benzophenone-3 with a sun protection factor (SPF) of 15, the UVA filter butyl methoxydibenzoylmethane, the SPF 15 sunscreen and the UVA filter together, and the lotion vehicle alone. Following sunscreen administration, mice received a single psoralen plus ultraviolet A radiation treatment. All sunscreens decreased chloramphenicol acetyl transferase activity with the SPF 15 sunscreen, the UVA filter, and the combination SPF 15 sunscreen and UVA filter, resulting in increasing degrees of protection against psoralen plus ultraviolet A radiation. These results demonstrate that this model functions as a rapid and sensitive model of UVA photodamage for the identification and comparison of compounds that protect against UVA-induced photoaging.     

Anophthalmic socket and orbital implants. Role of CT and MR imaging

The role of CT and MR imaging examination of orbital implants and the anophthalmic socket is expanding constantly. As the imaging techniques gain refinement and resolution, the list of potential clinical application grows. Frequent clinical-radiologic queries regarding the anophthalmic socket include neuro-radiologic findings with congenital anophthalmia or bilateral microphthalmia, the vascularization or position of an orbital implant following enucleation, or orbital recurrence of tumor following enucleation. Common clinical-radiologic questions regarding orbital implants relate to the associated findings of trauma, infection, bleeding, or recurrence of tumor in relationship to the existing orbital implant.     

Coats' disease and persistent hyperplastic primary vitreous. Role of MR imaging and CT

Coats' disease is an idiopathic disorder in which telangiectatic and aneurysmal retinal vessels leak a lipoproteinaceous exudate, with consequent bullous retinal detachment. It is a diagnostic challenge, and CT and MR imaging provide valuable information to differentiate it from other pathologies, particularly from retinoblastoma. Typical, advanced Coats' disease shows on CT a denser substance posterior to the vitreous, which on MR is hyperintense on all pulse sequences. Contrast administration on both CT and MR might give slight linear enhancement at the boundary between vitreous and exudation. Persistent hyperplastic primary vitreous (PHPV) is a unilateral disorder in a microphthalmic eye, seen in full-term infants. PHPV rarely is bilateral in patients with Norrie's disease, Warburg syndrome, or patients with retinal dysplasia. Persistent fetal vasculature leads to fibrosis, resulting in elongation of the ciliary processes, retinal detachment, and spontaneous cataracts. The CT appearance in the disorder is quite variable; however, MR imaging may be superior in demonstrating the enhancing retrolental mass and the elongated ciliary processes.     

Splenic hemangiomas and hamartomas: MR imaging characteristics of 28 lesions

The structure of the N-terminal region of mouse alpha-dystroglycan (DGN) was investigated by expression of two protein fragments (residues 30-180 and 30-438) in Escherichia coli cells. Trypsin susceptibility experiments show the presence of a stable alpha-dystroglycan N-terminal region (approximately from residue 30 to 315). In addition, guanidinium hydrochloride (Gdn/HCl) denaturation of DGN-(30-438)-peptide, monitored by means of tryptophan fluorescence, produces a cooperative transition typical of folded protein structures. These results strongly suggest that the alpha-dystroglycan N-terminal is an autonomous folding unit preluding a flexible mucin-like region and that its folding is not influenced by the absence of glycosylation. In order to obtain more information on the structural features of the N-terminal domain we have also used circular dichroism, analytical sedimentation and electron microscopy analysis. Circular dichroic spectra show the absence of typical secondary structure (e.g. alpha-helix or beta-sheet) and closely resemble those recorded for loop-containing proteins. This is consistent with a sequence similarity of the alpha-dystroglycan domain with the loop-containing protein elastase. Analytical ultracentrifugation and electron microscopy analysis reveal that the N-terminal domain has a globular structure. DGN-(30-438)-peptide does not bind in the nanomolar range to an iodinated agrin fragment which binds with high affinity to tissue purified alpha-dystroglycan. No binding was detected also to laminin. This result suggests that the alpha-dystroglycan N-terminal domain does not contain the binding site to its extracellular matrix binding partners. It is less likely than the lack of glycosylation reduces its binding affinity, because the N-terminal globular domain only contains two glycosylation sites.     

Insulinoma associated with liver lesions: value of MR imaging

We report on a middle-aged woman who presented with clinical and biochemical findings of insulinoma. Preoperative evaluation by ultrasound, CT, and angiography located the pancreatic lesion but also revealed two focal liver lesions. The latter were interpreted as metastases. MR imaging with injection of superparamagnetic iron oxide particles not only localized the insulinoma but proved to be the only noninvasive technique capable to exclude presence of liver metastases preoperatively. This reversed management to minimal laparoscopic surgery. Recent literature of preoperative imaging evaluation of insulinoma and focal liver lesions is discussed.     

Hepatic lesions: discrimination of nonsolid, benign lesions from solid, malignant lesions with heavily T2-weighted fast spin-echo MR imaging

PURPOSE: To determine whether the combined use of heavily and moderately T2-weighted fast spin-echo magnetic resonance (MR) images improves differentiation of non-solid, benign hepatic lesions from solid malignancies. MATERIALS AND METHODS: Three radiologists reviewed moderately (n = 133) and heavily (n = 133) T2-weighted and multiphasic dynamic contrast material-enhanced (n = 93) MR images in 133 patients with proved focal hepatic lesions (95 benign, 38 malignant). The radiologists used a five-point scale to rate their confidence in determination of malignancy. RESULTS: All three reviewers were statistically significantly better able to differentiate small (diameter less than 3 cm; n = 84) benignancies from small malignancies with the combination of moderately and heavily T2-weighted images (area under the receiver operating characteristic curve, 0.99 for each reader) than with moderately T2-weighted images alone (area, 0.88-0.90; P < .05). Confident diagnoses were rendered in 69 (82%) patients, with 100% accuracy for the combined use of moderately and heavily T2-weighted images. For larger lesions (diameter 3 cm or larger; n = 49), accurate differentiation was possible with moderately T2-weighted images alone. Additional use of multiphasic images did not improve the sensitivity, specificity, or accuracy of image interpretation. CONCLUSION: The combined use of moderately and heavily T2-weighted fast spin-echo MR images improves differentiation of small benign hepatic lesions from small malignant lesions.     

Hepatic cavernous hemangioma: sonographic patterns and speed of contrast enhancement on multiphase dynamic MR imaging

OBJECTIVE: Our purpose was to investigate a correlation between the speed of contrast enhancement in patients with hepatic cavernous hemangioma revealed by dynamic MR imaging and the internal echo pattern revealed by sonography. MATERIALS AND METHODS: Forty-five patients underwent multiphase IV contrast-enhanced dynamic MR imaging that revealed 71 hepatic cavernous hemangiomas less than 4 cm in diameter; the MR findings were compared with the sonographic findings in these patients. On MR imaging, the hemangiomas were classified as rapid-, intermediate-, and slow-enhancing. We classified sonographic features as hypoechoic, iso- or mixed-echoic, and hyperechoic according to the relative echogenicity seen between lesions and the surrounding hepatic parenchyma. Sonographic patterns and MR imaging findings of individual lesions were then compared. RESULTS: Rapid-enhancing hemangiomas revealed on dynamic MR imaging tended to be hypoechoic on sonography (18/24, 75%; p = .0143), and lesions that were slow-enhancing on MR imaging tended to be hyperechoic (26/29, 90%; p < .0001). Hypoechoic lesions on sonography tended to be rapid-enhancing on dynamic MR imaging (18/18, 100%). Likewise, hyperechoic lesions on sonography tended to be slow-enhancing on MR imaging (26/33, 79%; p = .0009). CONCLUSION: In most patients with hepatic cavernous hemangiomas, we found that the speed of contrast enhancement on multiphase dynamic MR imaging enabled us to predict the echo pattern in sonography and vice versa.     

Characterization of hepatic lesions by perfusion-weighted MR imaging with an echoplanar sequence

OBJECTIVE: The purpose of this study was to examine the usefulness of perfusion-weighted MR imaging with a single-shot gradient echoplanar sequence in characterizing hepatic tumors. SUBJECTS AND METHODS: Perfusion-weighted imaging was performed in 61 patients with 91 confirmed hepatic tumors (14 hemangiomas, 19 metastases, and 58 hepatocellular carcinomas). The perfusion-weighted imaging was started at the time of administration of 0.1 mmol/kg of gadolinium, and images were continuously obtained every 2 sec for 88 sec. Time-intensity curves for all the tumors were created for quantitative analysis. Patterns of enhancement were also evaluated. RESULTS: Changes in signal intensity that occurred throughout examination differed in three types of tumor. Transient signal intensity decreases in the perfusion phase significantly differed in three types of tumors (46% in hepatocellular carcinoma, 48% in hemangioma, and 15% in metastasis, p < .05 for hepatocellular carcinoma versus metastasis and for hemangioma versus metastasis). Signal intensity recovered rapidly for hepatocellular carcinoma and metastasis, whereas recovery was slower for hemangioma. Final signal intensity recovery was 94% in hepatocellular carcinoma, 91% in metastasis, and 54% in hemangioma compared with their initial signal intensities. (p < .05 for hepatocellular carcinoma versus hemangioma and for hemangioma versus metastasis.) The enhancement patterns also differed in three types of tumor. CONCLUSION: Perfusion-weighted imaging with a gradient echoplanar sequence provides real-time mapping of many points along the enhancement profile curves because of its excellent temporal resolution. Therefore, it accurately characterizes hepatic tumors based on their different negative-enhancement patterns.     

Neurologic, MR imaging, and MR spectroscopic findings in eosinophilia myalgia syndrome

BACKGROUND AND PURPOSE: Eosinophilia myalgia syndrome (EMS), a multisystemic disease induced by exposure to L-tryptophan, may result in serious CNS abnormalities. The purpose of this study was to determine the pattern of neurologic characteristics, MR imaging abnormalities, and brain neurometabolites in EMS. METHODS: Sixteen patients with EMS and CNS abnormalities (CNS-EMS) and 12 control subjects underwent evaluation, including medical and neurologic examination, proton MR spectroscopy, and MR imaging. RESULTS: Neurologic findings that were increased in CNS-EMS included minor depression (100%), amnesia (88%), and intermittent confusion (38%), although fatigue (31%), motor disorders (31%), recurrent headache (19%), major depression (13%), and dementia (6%) also occurred, but at a lesser significance. Self-reported disability was markedly increased in CNS-EMS. MR imaging findings included subcortical focal lesions, focal lesions in deep white matter, cortical atrophy, ventricular dilatation, and diffuse and periventricular white matter abnormalities. MR spectroscopic findings established two distinct spectral patterns: 1) increased choline-containing compounds, decreased N-acetylaspartate, and increased lipid-macromolecules, consistent with inflammatory cerebrovascular disease; and 2) increased glutamine, decreased myo-inositol, and decreased choline, consistent with acute CNS injury or metabolic encephalopathy. CONCLUSION: Neurologic abnormalities, self-reported disability, brain lesions, and MR spectroscopic abnormalities are common in CNS-EMS. The pattern of cerebral lesions and neurometabolites is consistent with widespread inflammatory cerebrovascular disease. However, a subgroup of patients with CNS-EMS have neurometabolic changes consistent with a metabolic encephalopathy identical or similar to hepatic encephalopathy. The neurologic abnormalities in EMS and related hypereosinophilic syndromes should be interpreted cautiously, with the recognition that both cerebrovascular injury and secondary metabolic encephalopathies may be involved.     

Macular hole in a case of choroidal melanoma

This study reports intraspecific variations of native isolates of Leishmania (Viannia) braziliensis from patients with leishmaniasis from Salta, Argentina. These isolates induced skin lesions in golden hamsters, initially showing rapid development, reaching their largest size between 28 and 35 days postinfection (PI). Thereafter, the infections were self-limiting and total regression was observed at 80-150 days PI. The majority of the native isolates were characterized by low infectivity in the experimental animals, and a classic pattern of dissemination to systemic organs was established. However, unusual features for L. braziliensis were displayed by two isolates; one showed evidence of high infectivity in hamsters characterized by a short prepatent period and larger, severe and persistent lesions at the inoculation site. The other isolate, of low infectivity, showed cutaneous metastasis and recurrent systemic dissemination in the same animals, suggesting dissociation between infectivity and pathogenicity. Metastasis has been frequently described in hamsters infected with L. (V) guyanensis and L. (V) panamensis, but not in infections induced by L. (V) braziliensis, as was observed in this study. Active and/or regressive histopathologic lesions were observed, depending on the stage of the infection. An exudative and mixed inflammatory pattern with microabscesses and necrotic areas was observed during early infection, while well-defined granulomas and collagen formation were the predominant features detected at a later time. Amastigotes were easily detected in the tissues, although in low numbers. Schaumann bodies were always detected. The characterization of the unique features of these native isolates, and the verification of their reproducibility in vitro and in vivo will be useful tools in tests related to immunoprophylaxis and chemotherapy.