Hodgkin's disease in association with hexavalent chromium exposure.

During an epidemiological study assessing cancer risk in a small isolated population exposed to excessive amounts of hexavalent chromium, we noted two patients with Hodgkin's disease after exposure for many years and after a long latency period. The study population demonstrated an observed risk between 65 and 92 times that of reported risks for non-exposed US populations. Although malignant lymphoma, as well as many other malignancies, has clearly been associated with hexavalent chromium exposure, no reports have yet specifically mentioned Hodgkin's disease. We herein report Hodgkin's disease specifically in two individuals so exposed. Although this may be a chance occurrence, clinicians should be aware of the potential association between hexavalent chromium exposure and Hodgkin's lymphoma.

CT diagnosis of unsuspected traumatic cataracts in patients with complicated eye injuries: significance of attenuation value of the lens.

OBJECTIVE: The purpose of this study was to determine whether the CT attenuation value of the lens is helpful in diagnosing acute traumatic cataracts in patients with complicated eye injuries that preclude evaluation by any other means. SUBJECTS AND METHODS: The CT attenuation values of the lenses of 69 patients with acute orbital trauma, including 24 patients with clinically and surgically diagnosed acute traumatic cataracts, were compared with attenuation values of their own contralateral lens and with the attenuation values of the lenses of 103 consecutive asymptomatic control subjects. The study group was composed of consecutive patients with unilateral orbital trauma who were clinically evaluated and referred for CT examination within 48 hr after their initial injury. In all patients, attenuation measurements of the injured lenses were obtained and compared with those of the contralateral lens as an internal control. All surgically diagnosed cataracts were histologically confirmed. RESULTS: The CT attenuation measurement of a lens in any asymptomatic control subject was identical (within the range of the standard deviation) to the measurement of the contralateral lens of that control patient. In patients with orbital injury, the CT attenuation of the patient's cataractous lens was markedly lower than in the contralateral lens (mean density difference, 30 H, p < .0001). This decreased attenuation corresponds to acute cataract formation with increased fluid within the lens. No patient with normal attenuation values of the lens in the traumatized globe (as compared with the contralateral lens) was found to have an acute traumatic cataract or have a cataract develop within a 1-year follow-up period. CONCLUSION: CT may be useful in the examination of patients with acute traumatic cataracts, unsuspected lens injury, opacification of the anterior chamber, or other injuries of the globe with complications that preclude lens evaluation by any other means. This prompt diagnosis may allow timely removal of the lens in appropriate clinical circumstances, preventing damage to the anterior chamber of the globe and other complications of delayed diagnosis and treatment. Further, normal CT findings at the time of trauma suggest that the lens will not undergo acute traumatic cataract formation.

Pigmented villonodular synovitis of a lumbar facet joint.

We describe the CT appearance of suspected pigmented villonodular synovitis involving a lumbar facet in a 51-year-old woman, and discuss how the histologic and radiologic appearances may differ from those of synovial cysts.

Lissencephaly-pachygyria associated with congenital cytomegalovirus infection.

We report the presence of major cerebral migrational defects in five severely, multiply handicapped children with congenital cytomegalovirus (CMV) infection. These patients had both computed tomographic (CT) scan and magnetic resonance imaging (MRI) evidence of marked migrational central nervous system defects consistent anatomically with the spectrum of lissencephaly-pachygyria, a disorder commonly idiopathic or associated with chromosomal abnormalities or with unknown early gestational insults. Neuroradiologic features included broad, flat gyri, shallow sulci, incomplete opercularization, ventriculomegaly, periventricular calcifications, and white-matter hypodensity on CT scans or increased signal intensity on long-TR MRI scans. Evidence for congenital CMV infection included prenatal onset of microcephaly, periventricular calcifications, neonatal jaundice, hepatomegaly, elevated CMV-specific immunoglobulin M, or viral isolation from urine. Previous reports of the neurologic sequelae of CMV have emphasized varying degrees of psychomotor retardation, cerebral palsy and epilepsy due to polymicrogyria, periventricular calcification, microcephaly, or rarely, hydrocephalus. Our patients appear to represent extremely severe examples of the effects of CMV on neurologic growth, maturation, and development. Recognition of these severe migrational abnormalities was improved by use of MRI, a technique that affords superior definition of the nature and extent of gyral and white-matter abnormalities. We suggest that these abnormalities may be more common than has previously been recognized.

Pachygyriclike changes: topographic appearance at MR imaging and CT and correlation with neurologic status.

Studies of 23 pediatric patients with pachygyriclike changes (PLCs) examined with computed tomography (CT) and magnetic resonance (MR) imaging were reviewed to determine topographic patterns and correlate them with various clinical syndromes and degrees of neurologic impairment. Three types of topographic distributions were identified: unilateral, diffuse, and bilateral nondiffuse (of which eight of 10 showed frontotemporal predominance). PLCs were an isolated finding in seven patients, were associated with various congenital syndromes in nine patients, and were associated with congenital infection in seven patients, six of whom showed marked white matter abnormalities. Although most patients had severe developmental delay, three with nondiffuse PLCs had less severe impairment, permitting less required care.

Wallerian degeneration and inflammation in rat peripheral nerve detected by in vivo MR imaging.

To investigate the role of MR imaging in wallerian degeneration, a series of animal models of increasingly complex peripheral nerve injury were studied by in vivo MR. Proximal tibial nerves in brown Norway rats were either crushed, transected (neurotomy), or transected and grafted with Lewis rat (allograft) or brown Norway (isograft) donor nerves. The nerves distal to the site of injury were imaged at intervals of 0-54 days after surgery. Subsequent histologic analysis was obtained and correlated with MR findings. Crush injury, neurotomy, and nerve grafting all resulted in high signal intensity along the course of the nerve observed on long TR/TE sequences, corresponding to edema and myelin breakdown from wallerian degeneration. The abnormal signal intensity resolved by 30 days after crush injury and by 45-54 days after neurotomy, when the active changes of wallerian degeneration had subsided. These changes were not seen in sham-operated rats. Our findings suggest that MR is capable of identifying traumatic neuropathy in a peripheral nerve undergoing active wallerian degeneration. The severity of injury may be reflected by the corresponding duration of signal abnormality. With the present methods, MR did not distinguish inflammatory from simple posttraumatic neuropathy.

Renal uptake of technetium-99m methylene diphosphonate following therapeutic radiation for vertebral metastases.

Radionuclide bone scans in two patients with breast cancer and concurrent chemotherapy treatment revealed increased band-like uptake of [99mTc]methylene diphosphonate along the medial upper renal cortex corresponding to the portions of the kidneys included within the radiation field. The latency of onset of abnormal uptake was 5 to 9 mo following completion of radiation in one patient, peaked near 13 to 14 mo for both patients, and returned to baseline after 20 to 27 mo. Transient serum creatinine level elevations were also detected. These findings suggest that transient subclinical renal impairment may occur and be detected on bone scans following inadvertent inclusion of renal cortex in radiation fields.

Fibrolamellar hepatocellular carcinoma: MR appearance.

We report two cases of fibrolamellar hepatocellular carcinoma, each of which had lower signal intensity than normal liver on short repetition time (TR), short echo time (TE) spin-echo (SE) images and demonstrated a central scar-like area of low signal intensity which did not become hyperintense on long time TR/TE SE images.

Fibrolamellar hepatocellular carcinoma: pitfalls in nonoperative diagnosis.

Results from ultrasonography, computed tomography (CT), scintigraphy, hepatic angiography, and magnetic resonance (MR) imaging were analyzed for five patients with surgically proved fibrolamellar hepatocellular carcinoma (FL-HCC)--a variant of hepatocellular carcinoma (HCC) that usually occurs in younger patients and has an improved prognosis and chance for curative resection. The radiologic findings were generally inconclusive for a differential diagnosis because the appearance of the lesions on the various imaging studies closely simulated that of either focal nodular hyperplasia, HCC, or metastases. CT and technetium-99m sulfur colloid scintigraphy were the most effective techniques for the workup of these lesions, but because they do not allow a definitive diagnosis, open biopsy is recommended for most lesions simulating focal nodular hyperplasia and HCC in younger patients. Although the current specificity of MR imaging in diagnosing liver lesions is low, further experience may permit more specific characterization of these lesions.

The fibrolamellar variant of hepatocellular carcinoma. Its association with focal nodular hyperplasia.

A case of fibrolamellar hepatocellular carcinoma (FL-HCC) associated with adjacent focal nodular hyperplasia (FNH) is described. These two regions were adjacent but distinct, both on gross and microscopic examination. Currently, it is unclear whether FL-HCC rarely arises in preexisting FNH, or whether FNH is a typical response to this vascular variant of hepatocellular carcinoma (HCC). The FNH region, which is peripheral, may be biopsied to exclude the underlying carcinoma, and thus lead to inadequate therapy. Previous reports of this association are reviewed.