Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia.

Predictability of the clinical course of juvenile dermatomyositis based on initial muscle biopsy: A retrospective study of 72 patients

OBJECTIVE

Except when the diagnosis of juvenile dermatomyositis (DM) is in doubt, a case has not been made for routine muscle biopsy (MB). We sought to determine whether MB findings prior to systemic therapy have prognostic value.

METHODS

We reviewed the hospital records and slides prepared from the initial open MB of 72 patients treated at one center between 1977 and 2002 and followed for a minimum of 2 years. None of the patients had received a course of systemic corticosteroid therapy at the time of MB. Our approach to MB evaluation was based on recent discussions with muscle pathology experts to develop criteria for assessing inflammation, vasculopathy, myofiber atrophy, regeneration, acute and chronic myopathic change, and stromal changes. Using simple and multivariate logistic regression, we tested each MB parameter for ability to predict outcome using 2 published classification systems.

RESULTS

Extensive active myopathic changes (excluding regeneration) and central nuclei without basophilia predicted chronic juvenile DM. Severe arteropathic change, positive arterial direct immunofluorescence, obvious foci of severe capillary loss/endomysial fibrosis, and muscle infarcts predicted chronic juvenile DM, particularly with ulceration. Other MB parameters, regardless of severity, were not significant predictors of chronic juvenile DM versus limited disease.

CONCLUSION

A scoring system for evaluating pretreatment MB in juvenile DM that focuses on extent of necrotizing myopathy, severity of vasculopathy, and features of established chronicity such as central nucleation of nonbasophilic myofibers may provide a basis for stratification of therapeutic regimens according to risk for chronic disease. The validity of our findings should be prospectively tested.

What more can we learn from muscle histopathology in children with dermatomyositis/polymyositis?

OBJECTIVE

To correlate disease course and complications in children with juvenile dermatomyositis (JDM) and polymyositis (JPM) with specific features of muscle pathology on biopsy.

METHODS

This is a retrospective cohort analysis of 59 children diagnosed with JDM or JPM between 1965 and 1998 and followed at the Cincinnati Children's Hospital Medical Center (CCHMC) for a mean duration of 7.3 years (range 1.1-24.5 years). Disease course was characterized as limited, chronic non-ulcerative or chronic ulcerative, similar to previously defined disease course subtypes reported by Crowe et al.(1). All subjects had diagnostic muscle biopsies performed at CCHMC and had disease for at least two years' duration in order to classify their disease course as either limited or chronic. Features of muscle histopathology that were evaluated included loss of the intramuscular capillary bed, infarct, perifascicular myopathy, direct immunofluorescence (DIF) staining of the intramuscular vasculature and specifically, the locale of DIF staining, i.e., small arteries or capillaries. Disease complications that were assessed included calcinosis, contractures, muscle atrophy, lipodystrophy, gastrointestinal ulceration, cutaneous ulceration and death. Data analysis was completed using Chi-square or Fisher's exact tests and logistic regression modeling.

RESULTS

Twenty-two children (37%) had limited disease, 24 (41%) had chronic non-ulcerative disease and 13 (22%) had chronic ulcerative disease. Neither loss of the intramuscular capillary bed nor perifascicular myopathy on muscle biopsy significantly correlated with disease course or the various complications evaluated in this study. DIF staining of intramuscular vessels overall was not significantly associated with clinical disease course, but the localization of DIF staining to intramuscular arteries (rather than to capillaries) was significantly associated with the outcome of chronic ulcerative disease. Nine of the 13 children with chronic ulcerative disease had DIF-arterial staining on muscle biopsy (69%), significantly greater than DIF-arterial staining in children with limited disease (32% had DIF-arterial staining) (p = 0.04), chronic non-ulcerative disease (8% had DIF-arterial staining) (p = 0.0002), and non-ulcerative disease overall (limited + chronic non-ulcerative disease groups combined) (20% had DIF-arterial staining), with p = 0.001. Additionally, lack of DIF-arterial staining on biopsy was significantly correlated with patients not having gastrointestinal ulceration (p = 0.002), cutaneous ulceration (p = 0.004) and/or death (p = 0.02) as disease-related complications. Infarct on muscle biopsy was significantly associated with the development of chronic ulcerative disease (p = 0.02), being present on biopsy in 23% of children with chronic ulcerative disease compared with none of the patients with chronic non-ulcerative disease and 4% of those with limited disease. Infarct on muscle biopsy correlated with the outcomes of death (p = 0.01) and gastrointestinal ulceration (p = 0.03), but not with the development of cutaneous ulceration (p = 0.18).

CONCLUSION

DIF-arterial staining and infarct on muscle biopsy are significantly associated with the development of chronic ulcerative disease in JDM and JPM, while perifascicular myopathy and loss of the intramuscular capillary network are not associated with disease course. The presence of DIF-arterial staining and infarct on biopsy should suggest early use of second-line therapeutic agents to more quickly bring disease activity under control.

Transgenic overexpression of cardiac actin in the mouse heart suggests coregulation of cardiac, skeletal and vascular actin expression

Previous studies have shown that depletion of cardiac actin by targeted disruption is associated with increased expression of alternative actins in the mouse heart. Here we have studied the effects of transgenic overexpression of cardiac actin using the alpha-myosin heavy chain promoter. Lines carrying 7 or 8 copies of the transgene showed a 2-fold increase in cardiac actin mRNA and also displayed decreased expression of skeletal and vascular actin in their hearts. In contrast, a line with more than 250 copies of the transgene did not show a similar decrease in the expression of skeletal and vascular actin despite a 3-fold increase in cardiac actin mRNA. While the low copy number transgenic mice displayed hearts that were similar to non-transgenic controls, the high copy number transgenic line showed larger hearts with distinct atrial enlargement and cardiomyocyte hypertrophy. Further, while the low copy number transgenic mouse hearts were mildly hypocontractile when compared with non-transgenic mouse hearts, the high copy number transgenic mouse hearts were significantly so. We conclude that in the presence of a small number of copies of the cardiac actin transgene, homeostatic mechanisms involved in maintaining actin levels are active and negatively regulate skeletal and vascular actin levels in the heart in response to increased expression of cardiac actin. However, these putative mechanisms are either inoperative in the high copy number transgenic line or are countered by the enhanced expression of skeletal and vascular actin during cardiomyocyte hypertrophy.

Etanercept in the treatment of macrophage activation syndrome

Macrophage activation syndrome (MAS), a recognized complication of systemic juvenile rheumatoid arthritis (sJRA), has been associated with significant morbidity and mortality. Dysregulation of macrophage-lymphocyte interactions leading to uncontrolled proliferation of highly activated macrophages and massive release of proinflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha) appears to be central to the pathogenesis of this syndrome. Until now the mainstay of therapy has been corticosteroids and cyclosporin A. We describe a patient with MAS and sJRA successfully treated with the anti-TNF agent etanercept. The outcome in this patient suggests etanercept might be an effective therapeutic agent in MAS.

Liver disease caused by disorders of bile acid synthesis

Bile acid synthetic defects are uncommon disorders that cause progressive cholestatic liver disease that is often lethal in infancy or early childhood. Five specific primary defects have been described. Diagnosis is based on mass spectrometry of urine and serum. Pathogenesis of liver injury is related to persistent reduction in levels of normal bile acids and accumulation of abnormal, potentially hepatotoxic, intermediaries. Sites of injury are the liver cell, the bile canaliculus, and the smallest bile ductules. The interlobular bile ducts are normal. The liver lesion is progressive chronic hepatitis with an especially high incidence of GCT in patients who present in infancy. Bile acid replacement therapy is usually effective in arresting the liver injury. Regression of liver damage has been documented during treatment of patients who were diagnosed early in life. Because bile acid synthetic disorders are the only cholestatic diseases of infancy in which GCT of hepatocytes is consistently present, the author suggest that the injury responsible for GCT may be specific for toxic bile acids. Accordingly, immaturity of the bile acid synthetic pathway may render many otherwise normal infants vulnerable to transient "neonatal hepatitis" with GCT in a broad range of cholestatic disorders.

Nucleophosmin/B23 is a target of CDK2/cyclin E in centrosome duplication

In animal cells, duplication of centrosomes and DNA is coordinated. Since CDK2/cyclin E triggers initiation of both events, activation of CDK2/cyclin E is thought to link these two events. We identified nucleophosmin (NPM/B23) as a substrate of CDK2/cyclin E in centrosome duplication. NPM/B23 associates specifically with unduplicated centrosomes, and NPM/B23 dissociates from centrosomes by CDK2/cyclin E-mediated phosphorylation. An anti-NPM/B23 antibody, which blocks this phosphorylation, suppresses the initiation of centrosome duplication in vivo. Moreover, expression of a nonphosphorylatable mutant NPM/ B23 in cells effectively blocks centrosome duplication. Thus, NPM/B23 is a target of CDK2/cyclin E in the initiation of centrosome duplication.

Premature closure of foramen ovale and renal vein thrombosis in a stillborn twin homozygous for methylene tetrahydrofolate reductase gene polymorphism: a clinicopathologic case study

Premature closure of the foramen ovale, 4-chamber cardiac hypertrophy, and renal vein/vena cava thrombosis were found at autopsy of a stillborn dizygotic twin at 36 weeks gestational age. Review of the original prenatal sonograms showed features suggestive of early closure of the foramen ovale. Homozygosity for the 5, 10 methylene tetrahydrofolate reductase mutation was shown only in the affected twin after the parents were found to be heterozygous for the mutation. The difference in outcome of the twins following prenatal treatment with beta mimetics and corticosteroids for preterm labor may be related to the added susceptibility factor for thromboembolism associated with presumed hyperhomocysteinemia in the proband which was not shared by the surviving healthy twin. The role of premature closure of the foramen ovale and prenatal treatment are discussed but remain uncertain.

DNA fragmentation factor 45-deficient cells are more resistant to apoptosis and exhibit different dying morphology than wild-type control cells

The DNA fragmentation factor 45 (DFF45) is a subunit of a heterodimeric DNase complex critical for the induction of DNA fragmentation in vitro. To understand the in vivo role of DFF45 in programmed cell death, we measured the expression of DFF45 during mouse development and compared DNA fragmentation and viability of DFF45-deficient cells with wild-type control cells after activation of apoptosis. We found that DFF45 is ubiquitously expressed throughout mouse development. Moreover, DFF45-deficient thymocytes are resistant to DNA fragmentation with in vivo dexamethasone treatment. Furthermore, primary thymocytes from DFF45 mutant mice are also more resistant to apoptosis than wild-type control cells on exposure to several apoptotic stimuli. Dying DFF45-deficient thymocytes exhibit different morphology than wild-type control cells in that they show reduced degree of chromatin condensation, absent nuclear fragmentation, intranuclear cytoplasmic invagination, and striking nuclear chromatin conglutination after release from disintegrating cells. These results indicate that DFF45 is essential during normal apoptosis.

Visualization of aortic valve leaflets using black blood MRI

Although magnetic resonance imaging (MRI) is capable of imaging various physiological parameters associated with the heart valves, it has generally been difficult to visualize the valve leaflets directly. The aortic valve was imaged in 120 patients referred for cardiac MRI to assess myocardial volumes or mass. The average patient age was 37 and ranged from 9 to 75 years. Heart rate ranged from 43 to 100 bpm. Imaging was performed on a 1.5 T scanner equipped with enhanced gradients and a cardiac phased-array coil. A double inversion recovery fast spin-echo sequence was used to acquire short-axis images of the aortic valve in a breath-hold (15 +/- 3 seconds). All three leaflets of the aortic valve were seen in 102 of 120 studies (85%). Two leaflets were detected in another 15 subjects. No leaflets were seen in three individuals. Seven cases of a bicuspid or thickened aortic valves were clearly distinguished from normal valves. The signal-to-noise ratio of aortic leaflets (14 +/- 5) was significantly higher than that of the residual blood signal in the aortic root (7 +/- 4, P < 0.001). MR images showed the aortic valve leaflets in a high fraction of people with suspected normal aortic valves and detected seven cases of abnormal aortic valves. The potential of MRI to study both the anatomic and functional consequences of valvular heart disease warrants further study. J. Magn. Reson. Imaging 1999;10:771-777.

Diagnosis of hirschsprung disease using the rectal biopsy: multi-institutional survey

Diagnostic pathologists remain uncomfortable with the diagnosis of Hirschsprung disease (HD) via rectal (mucosal/submucosal) biopsy and with performance and interpretation of the associated acetylcholinesterase (AChE) assay. This report details the different diagnostic approaches taken by four major pediatric institutions-Children's Hospital, Columbus, OH; Children's Hospital Medical Center, Cincinnati, OH; Children's Hospital, Pittsburgh, PA; Children's Hospital, Los Angeles, CA-in confirming or excluding the presence of HD. The Columbus approach emphasizes serial morphologic examination of rectal biopsies, while Cincinnati emphasizes the primary diagnostic utility of the AChE stain. Pittsburgh and Los Angeles emphasize a detailed gross and microscopic analysis of rectal biopsies to detect both conventional HD and its more rare subtypes. The diagnostic approaches of these four institutions can be used on a complementary basis to the advantage of the general diagnostic pathologist, especially in HD cases with subtle clinical presentations. The need for careful and continual communication between the clinician and pathologist in diagnosing or excluding the presence of HD is imperative.

Wilms' tumor and related abnormalities in the fetus and newborn

Mesoblastic nephroma, a benign tumor, is the most common renal neoplasm in neonates. Wilms' tumor (WT) may occur in newborn infants, but is more common in older children. The molecular genetics of WT involves one or more genes located on Chromosome #11 and probably other locations not yet elicidated. Germline mutations cause less than 5% of WTs; most WTs are sporadic. Precursor lesions to WT called nephrogenic rests may be detected before evolution to WT by imaging studies. Developmental anomalies comprising several different syndromes are associated with nephrogenic rests and predisposition to WT. Prospective surveillance for WT may be feasible in high risk infants identified on the basis of physical findings followed by testing for predisposing gene defects and periodic imaging of the kidneys and other organs at risk until the period of risk has ended.

Pathological evidence of prolonged umbilical cord encirclement as a cause of fetal death

A case is presented in which autopsy findings (deep groove around the fetal waist and buttock), and gross and microscopic umbilical cord and placental examination (linear ulcer of umbilical cord histologically rimmed by fetal epidermal implants with evidence of remote bleeding) established the diagnosis of umbilical cord encirclement as a cause of intrauterine fetal death despite the lack of prenatal or postnatal obstetrical evidence.

Model for evaluating the effect of growth factors on the larynx

Growth factors are proteins that help regulate the inflammatory response and wound healing in tissues. After laryngotracheal surgery, proper wound healing is important in maintaining the reconstructed airway. The application of growth factor to the respiratory mucosa of the larynx and its effect on wound healing within the airway have not been studied. This study was designed to establish a model for the evaluation of wound healing after the application of growth factor to composite respiratory mucosa and cartilage surfaces at the time of laryngotracheoplasty. Forty rabbits underwent anterior cricoid cartilage split with or without the use of a cartilage graft. Platelet-derived growth factor or a placebo substance was applied to the wound at the time of surgery. This study offers a model for studying wound healing in the airway that is reproducible with limited morbidity.

The relationship of hepatotoxic risk factors and liver histology in methotrexate therapy for juvenile rheumatoid arthritis

OBJECTIVE

To examine the relationship between hepatotoxic risk factors and liver histopathology in patients with juvenile rheumatoid arthritis (JRA) treated with methotrexate (MTX).

STUDY DESIGN

We graded the histology of 33 percutaneous liver biopsy specimens from 25 patients with JRA treated at Children's Hospital Medical Center, Cincinnati, Ohio, using the Roenigk Classification Scale. Stepwise linear and logistic regression analyses were performed to examine the relationship of the Roenigk grade and presence of liver fibrosis of biopsy specimens with potential risk factors.

RESULTS

Twenty-seven biopsy specimens (82%) were classified as grade I, 4 (12%) as grade II, and 2 (6%) as grade IIIA; none demonstrated significant fibrosis. The frequency of biochemical abnormalities (P <.001) and body mass index (P =.05) were the only risk factors found to significantly relate to the Roenigk grade. The following factors were not significantly associated with the Roenigk grade: age, gender, disease duration, JRA subtype and course, duration of MTX administration, weekly MTX dose, cumulative dose of MTX, route of MTX administration, use of folic acid supplementation, concurrent use of other medications, and potential hepatotoxic comorbidities.

CONCLUSIONS

Serial biochemical abnormalities are significantly associated with Roenigk grade and the presence of liver fibrosis. These findings concur with studies of patients with rheumatoid arthritis, suggesting that guidelines for monitoring MTX hepatotoxicity in rheumatoid arthritis may be applicable to patients with JRA.

Alveolar capillary dysplasia with misalignment of the pulmonary veins: a rare but fatal cause of neonatal respiratory failure

Respiratory failure in the neonate that is refractory to maximal medical management is a frequent indication for extracorporeal life support (ECLS). Alveolar capillary dysplasia with misalignment of the pulmonary veins is an irreversible cause of respiratory failure that cannot be diagnosed on clinical grounds alone and would not be expected to respond to ECLS therapy. A recent experience with a patient prompted us to review the literature regarding this condition for the purpose of identifying factors suggestive of this diagnosis. This condition should be considered in neonates with presumed pulmonary hypertension who cannot be weaned from ECLS. If the diagnosis is made by antemortem open-lung biopsy, a costly, protracted, and unnecessary continued course of ECLS may be avoided.

Third report of t(19q)(13.4) in mesenchymal hamartoma of liver with comments on link to embryonal sarcoma

We report the third known case of mesenchymal hamartoma of the liver (MHL) with a balanced translocation involving a common breakpoint, 19q13.4. A common clonal chromosome abnormality appears to characterize an important subset of MHL, some of which may be low-grade neoplasms. We found no consistent karyotype abnormality in a post-treatment sample of embryonal sarcoma of the liver (ESL). Reports of coexistent MHL and ESL in two patients and detection of 19q abnormalities in two ESLs appear to support Stocker's hypothesis of a histogenetic link between these two rare liver lesions. More data are needed to clarify this relationship. It is possible that MHLs are etiologically heterogenous and may be developmental disorders, disruptions, or neoplasms.

Evaluation of the aortic root by MRI: insights from patients with homozygous familial hypercholesterolemia

BACKGROUND

In homozygous familial hypercholesterolemia (HFH), the aortic root is prone to develop atherosclerotic plaque at an early age. However, the aortic wall and plaque have not yet been assessed in this condition by MRI. We evaluated the aortic root by use of MRI in 17 HFH patients and 12 normal control subjects in a prospective, blinded, controlled study.

METHODS AND RESULTS

Morphological assessment of the aortic root was done with spin-echo and gradient-echo MRI scanning. Comparisons were made with a number of measures of disease severity, including cholesterol-year score, calcium score on electron-beam CT (EBCT), and size of Achilles tendon xanthomas. Atherosclerotic plaque, visible on fat-suppressed images but never on water-suppressed images, was present in 9 HFH patients (53%). Supravalvular aortic stenosis was present in 7 patients with HFH (41%). Maximum supravalvular aortic wall thickness was significantly greater and OD and lumen cross-sectional area (CSA) were smaller in patients than in control subjects (P=0.006, 0.0005, and 0.06, respectively). Maximum wall thickness was associated with a greater calcium score on electron-beam CT (P=0.02). Although the cumulative exposure of the aortic root to cholesterol (the cholesterol-year score) was significantly correlated with the Achilles tendon CSA and vascular calcification, this score did not correlate with the wall thickness or aortic CSA.

CONCLUSIONS

This study not only demonstrates the utility of MRI for detecting and characterizing aortic root atherosclerotic plaque and supravalvular aortic stenosis in HFH patients but also suggests that the LDL receptor plays a direct or indirect role in aortic mural development and vascular growth.

The large window ductus: a surgical trap

A rare window type of patent ductus arteriosus is reported that was large (15 mm in maximal transverse dimension) but had virtually no length and hence was externally invisible. The smaller aortic isthmus (4 mm in diameter), which was intrapericardial, was mistaken for the ductus and was inadvertently clip-occluded, leading to death. After a specific diagnosis is made, the large window ductus should be patched on cardiopulmonary bypass with a transpulmonary approach.

Formation of intracerebral cavernous malformations after radiation treatment for central nervous system neoplasia in children

OBJECT

Radiation is a common treatment modality for pediatric brain tumors. The authors present a retrospective review of six children who developed cerebral cavernous malformations after they underwent radiation treatment for central nervous system (CNS) neoplasia and propose two possible models to explain the formation of cavernous malformations.

METHODS

Three boys, aged 13, 9, and 17 years, suffered intracerebral hemorrhages from cerebral cavernous malformations 87, 94, and 120 months, respectively, after they received whole-brain radiation therapy (WBRT) for acute lymphocytic leukemia. A 10-year-old girl and a 19-year-old man developed temporal lobe cavernous malformations 46 and 48 months, respectively, after they received radiation therapy for posterior fossa astrocytomas. A 12-year-old girl developed a temporal lobe cavernous malformation 45 months after WBRT was administered for a medulloblastoma. In all of these cases the cavernous malformation appeared in the irradiated field, was not known to be present prior to radiation therapy, and developed after a latency period following treatment. The incidence of cavernous malformations in these patients suggests that children who undergo radiation therapy of the brain may have an increased risk of hemorrhage.

CONCLUSIONS

Two possible models may explain the formation of cavernous malformations following brain radiation in these patients. First, the cavernous malformations may form de novo in response to the radiation. Second, the cavernous malformations may have been present, but radiographically occult, at the time of radiation therapy and may have hemorrhaged in response to the radiation. The authors conclude that cavernous malformations may develop after brain radiation and propose a possible mechanism for this formation.

The long-term effect of methotrexate therapy on the liver in patients with juvenile rheumatoid arthritis

OBJECTIVE

To determine if the long-term use of methotrexate (MTX) in juvenile rheumatoid arthritis (JRA) is associated with the development of significant liver fibrosis, and to describe the presence of risk factors for liver fibrosis in patients with JRA.

METHODS

Needle biopsies of the liver were performed on a cross-section cohort of 14 patients with JRA who had received a total cumulative dose of MTX that was either > 3,000 mg or > 4,000 mg/1.73 m2 of body surface area. Biopsy samples were independently graded according to the Roenigk Classification Scale by 2 pathologists. The presence of risk factors for MTX hepatotoxicity, especially biochemical abnormalities reflective of liver injury and alcohol consumption, were assessed.

RESULTS

Thirteen biopsy samples (93%) were classified as grade I, and 1 (7%) as grade II; none demonstrated significant fibrosis. However, histologic abnormalities were found in 13 biopsy samples (93%). Only 2 patients (14%) consumed more than 1 alcoholic drink per month. Thirteen patients (93%) had biochemical abnormalities while being treated with MTX, but only 5 patients (36%) had at least 1 determination in which the aspartate or alanine aminotransferase elevation was > 3 times the upper limit of normal.

CONCLUSION

Long-term use of MTX for JRA does not appear to be associated with the development of significant liver fibrosis. Although nearly all patients had minor histologic changes, no significant clinical consequences were apparent. A prospective study of a larger population will more accurately define the incidence of MTX-related liver fibrosis and appropriate monitoring guidelines in JRA.

Distinct pattern of ret oncogene rearrangements in morphological variants of radiation-induced and sporadic thyroid papillary carcinomas in children

In this study, we compare the morphological and genetic characteristics of 38 post-Chernobyl thyroid papillary carcinomas from Belarussian children 5-18 years old with those of 23 sporadic papillary carcinomas from the same age children without history of radiation exposure from Los Angeles and Cincinnati. Among radiation-induced tumors, solid variant of papillary carcinoma was found in 37%, follicular in 29%, typical papillary in 18%, and mixed and diffuse sclerosing variants in 8% each. In the sporadic group, a typical papillary pattern was prevalent in 70%, follicular in 17%, diffuse sclerosing variant in 9%, and solid in 4%. In both groups, the prevalence of ret rearrangements was high, but the frequency of specific types of rearrangement was significantly different. Among radiation-induced tumors, ret/PTC3 was found in 58%, ret/PTC1 in 16%, and ret/PTC2 in 3%, whereas among sporadic tumors, ret/PTC1 was found in 47% (P < 0.05), and ret/PTC3 was found in 18% (P = 0.01). The morphological variants of papillary carcinoma showed different prevalence of the specific types of ret rearrangement. Seventy-nine % of solid variant tumors had ret/PTC3, whereas only 7% had ret/PTC1 (P = 0.0007). Among typical papillary tumors, ret/PTC1 was found in 38%, ret/PTC3 in 19%, and ret/PTC2 in 5%. Thus, ret rearrangements are highly prevalent in pediatric papillary carcinomas from children exposed to radiation and in those occurring sporadically. However, the types of ret/PTC vary between these two populations, with ret/PTC3 present more commonly in post-Chernobyl tumors. Furthermore, solid variants have a high prevalence of ret/PTC3, whereas typical papillary carcinomas do not, suggesting that the different types of ret rearrangement confer neoplastic thyroid cells with distinct phenotypic properties.

Practice guidelines for autopsy pathology: the perinatal and pediatric autopsy. Autopsy Committee of the College of American Pathologists

The Autopsy Committee of the College of American Pathologists has prepared this guideline in conjunction with representatives of other organizations to assist pathologists in the reporting of perinatal and pediatric autopsies. The guideline is to be regarded as being primarily an educational tool. Application of these recommendations on autopsy reporting is to be made on the basis of the judgment of the pathologist engaged in a specific case.

Acute testicular torsion: comparison of unenhanced and contrast-enhanced power Doppler US, color Doppler US, and radionuclide imaging

PURPOSE

To compare the usefulness of conventional color Doppler ultrasound (US), unenhanced and contrast material-enhanced power Doppler US, and radionuclide imaging in a model of acute testicular torsion.

MATERIALS AND METHODS

Twenty rabbits underwent unilateral 360 degree testis torsion and contralateral orchiopexy. Gray-scale, color Doppler, and unenhanced and contrast-enhanced power Doppler US were performed 4-6 hours later. The side of torsion was determined, and intratestis flow was graded. Within 2 hours of US, technetium-99m pertechnetate was intravenously administered, the rabbits were killed, and the testes excised for radionuclide imaging.

RESULTS

Intratestis perfusion was detected in 85% of torsed testes at US and radionuclide imaging. The side of torsion was correctly diagnosed in 25% of cases with radionuclide imaging and in 60% of cases with US. Power Doppler US demonstrated significantly greater intratestis flow in pexed than in torsed testes. Although the numbers of correct diagnosis with the three US modalities were similar, flow grades within torsed and normal testes were significantly different.

CONCLUSION

Perfusion to torsed and normal testes was demonstrated equally well with color Doppler US, power Doppler US, and radionuclide imaging. Doppler US better depicted differences in intratesticular flow between torsed and normal testes.

Hepatoblastoma in a child with trisomy 18: cytogenetics, liver anomalies, and literature review

A 26-month-old female with trisomy 18 and repaired omphalocele died of metastatic disease after resection of hepatoblastoma (HB) at 21 months of age. Four other cases (three of them published) suggest that the association of trisomy 18 and HB may be nonrandom. Karyotype abnormalities of the tumor in our case included duplication of 2q and +20, reported previously in HB arising in patients with normal karyotype. Antecedent growth disturbance of liver, either intrinsic (abnormal lobation) or related to contiguous extrinsic anomalies such as omphalocele or local diaphragmatic hypoplasia and possibly augmented by unusual sensitivity to noxious environmental agents, may predispose to hepatoblastoma in trisomy 18. Longevity in trisomy 18 predisposes to both hepatoblastoma and Wilms tumor, possibly by a shared pathway.

Normal changes in the MR appearance of the spleen during early childhood

OBJECTIVE

During the first year of life, the spleen undergoes histologic changes as the lymphoproliferative system matures. The purposes of this study were to describe the normal MR appearance of the spleen during infancy and early childhood and to correlate imaging findings with age-related histologic changes.

MATERIALS AND METHODS

The spleen was evaluated on 28 abdominal MR studies obtained during the first 23 months of life. Splenic signal intensity was compared to that of the liver. Selected autopsy specimens were compared with the imaging results.

RESULTS

The T2-weighted signal intensity of the spleen gradually increased from isointense to hypointense relative to the liver during the first week of life to moderately hyperintense to the liver by 8 months of age. T1-weighted splenic signal intensity gradually decreased. These findings corresponded to histological increases in white-pulp-red-pulp ratios.

CONCLUSION

Before the lymphoid system completely matures, the T2-weighted signal intensity of the normal neonatal spleen appears decreased compared with the moderately hyperintense splenic signal seen in older children and adults. This finding should not be mistaken for disease.

Alexander disease: a case report and review of the literature

Alexander disease (AD) is a rare progressive lethal leukodystrophy usually affecting infants and characterized by progressive failure of central myelination and accumulation of Rosenthal fibers (RFs) in astrocytes. Despite strong male predilection and infrequency of involved siblings, an autosomal recessive mode of inheritance is presumed. We report a typical case of infantile AD with imaging studies, a complete autopsy, and a critical literature review. Recent studies of AD have identified several stress proteins plus glial fibrillary protein as major constituents of RFs but have not clarified the basic defect. Advances in understanding of astrocyte function suggest an important role in the process of myelination that may be interrupted in AD. The nosology of putative juvenile-onset and adult-onset examples continues to be uncertain.

Relative microbial resistance of gastric, ileal and cecal bladder augmentation in the rat

PURPOSE

Bladder resistance to bacterial infection after gastrocystoplasty, ileocystoplasty and cecocystoplasty was investigated in the rat.

MATERIALS AND METHODS

Bladders were infected with Escherichia coli 6 to 13 months after augmentation and urine culture was obtained weekly for 3 months.

RESULTS

No differences were observed in the number of infected animals within each group or electrolyte data among groups. The number of animals infected after surgery but before E. coli challenge was lowest in the gastrocystoplasty group. Bladder stones formed only in ileocystoplasty and cecocystoplasty groups. No group had a change in urinary pH.

CONCLUSIONS

Gastrocystoplasty may be associated with a lower incidence of spontaneous infection and stone formation. An aggressive infection protocol may have masked differences in susceptibility to infection. Since urinary pH was unchanged after gastrocystoplasty, use of the rat may not be appropriate for augmentation studies.

Comparison of color Doppler sonography and radionuclide imaging in different degrees of torsion in rabbit testes

RATIONALE AND OBJECTIVES

We compared color Doppler sonography and radionuclide imaging in an animal model of variable torsion of the testes.

METHODS

The testes of 19 rabbits with unilateral 0 degree (nontorsion), 180 degrees, 360 degrees, or 540 degrees torsion and contralateral nontorsion were evaluated by sonography serially over 24 hr. Color Doppler sonography and radionuclide imaging at 24 hr were compared and correlated with pathology in a subset of testes.

RESULTS

Nontorsion (n = 16 testes) and 540 degrees torsion (n = 7 testes) were always correctly diagnosed at 24 hr by color Doppler sonography and radionuclide imaging. Torsion at 180 degrees (n = 2) was indistinguishable from nontorsion. With 360 degrees torsion (n = 6 testes), four testes had reduced or absent flow with color Doppler sonography, whereas only one testis was abnormal with radionuclide imaging.

CONCLUSION

Nontorsion and extreme torsion of rabbit testes are well documented by radionuclide imaging and color Doppler sonography. Torsion at 360 degrees can result in variable flow alterations that are better detected by color Doppler sonography than by radionuclide imaging.

Pathological findings in Gaucher disease type 2 patients following enzyme therapy

The pathological outcomes following intravenous acid beta-glucosidase (alglucerase) infusions were compared in two siblings with Gaucher disease type 2, the acute neuronopathic variant. In case 1 enzyme infusions (four doses at 7 months) had no effect when severe progressive visceral and neuronopathic disease were present. Death from progressive disease occurred at 9 months. Case 2 was prenatally diagnosed. Enzyme infusions were initiated presymptomatically at 4 days of age and continued until death at 15.2 months. Development progressed satisfactorily, albeit at a slower than normal rate until age 10 months when progressive brain stem involvement became evident. Death occurred after slowly progressive brain stem dysfunction, but gross motor and cognitive skills were nearly normal. Postmortem light and electron microscope (EM) studies in both cases showed typical central nervous system (CNS) findings and massive infiltration of the lungs and lymph nodes by Gaucher cells. The liver, spleen, and bone marrow, except that in the temporal bone, in case 2 were normal. These studies show that enzyme therapy may slow but does not prevent the development of lethal CNS disease in Gaucher disease type 2, even when initiated presymptomatically. These findings also indicate the nonuniformity of tissue responses to enzyme therapy implying the existence of therapeutically inaccessible compartments that, in less severe variants, may create unexpected long-term disease complications.

Proliferation and maturation indices in nephrogenic rests and Wilms tumor; the emergence of heterogeneity from dormant nodular renal blastema

Independent nephrogenic rests (NRs) accompany many Wilms tumors (WTs), exhibit a range of qualities suggesting dormancy, maturation, regression, and hyperplasia, and may carry the WT-1 mutation. We assessed nucleolar organizer regions, proliferating cell nuclear antigen (PCNA) activity, cytoplasmic filament expression, and nuclear morphology in 79 nephrogenic rests accompanying 20 WTs. We found a direct relationship between the size of a blastematous NR and the AgNOR number per nucleus and a close correlation with PCNA activity. The blastema of most NRs > 1 cm in diameter was indistinguishable from blastema of most WTs. The smallest NR usually had a low number of silver-reactive nucleolar organizing regions (AgNORs), low PCNA activity, and absent cytoplasmic filaments, all characteristics of a nascent dormant state in which both proliferation rate and protein synthetic activity are low. Intermediate filament expression was variable in blastema of larger NRs; cytoplasmic filaments correlated with emergence of epithelial maturation and absence of filaments with accumulation of immature cells; mature epithelial structures in NRs had low AgNOR number and PCNA activity representing a terminal dormant state. The majority of blastemal cells in most WTs and in one-third of large hyperplastic NRs lack cytoplasmic filaments. This, plus the occasional finding in large NRs of features more typical of WTs such as prevalence of apoptosis, patches of frank necrosis, multinodular architecture, and expanses of monomorphic, poorly vascularized blastema with low PCNA activity, suggest that it may be possible to distinguish NRs that are progressing toward WT from those that are merely hyperplastic. This study refines the concepts of dormancy and hyperplasia as expressed in NRs and provides a general framework for probing the relationship of molecular events to progression of a small proportion of NRs to WT. Criteria used herein to define dormancy and hyperplasia may be useful in assessing lesions other than typical WT, such as unusually large or extensive NRs or uncommon differentiated WTs where the potential for aggressive behavior may be lower than in usual WTs.

Immune-mediated regression of 'metastatic' neuroblastoma in the liver

It is understood that neuroblastoma (NB) in the liver of patients with clinical stage IV-S disease may disappear, but the mechanism of such regression is unclear. A genetic hypothesis has previously been suggested, although heretofore an immunologic explanation had not been reported. Using C1300 NB in AJ mice, we developed a model of liver metastatic disease by directly injecting tumor cells into a subcutaneously translocated spleen. Intrasplenic inoculation of 2 x 10(6) C1300 NB cells produced liver subcapsular foci of NB in 100% of animals, whose mean survival period was 18 days. Three days after tumor inoculation, interleukin-2 (IL-2) (2,400 U/d) was continuously infused for 14 days via a miniosmotic pump, and daily survival was followed. Animals were sampled serially by histological and immunohistochemical staining. Animal survival was significantly prolonged (P < .05) in the IL-2 group when compared with that of saline controls, but importantly, 50% of the mice were cured. Histological examination showed early infiltration of mononuclear cells, predominantly lymphocytes, around liver metastatic foci; and phenotypic analysis of these cells showed them to be Thy-1.2-positive and asialo GM1-positive, suggesting they are of natural killer (NK) and lymphokine-activated killer (LAK) origin. Most importantly, in cured animals the histological analysis of the liver demonstrated reversion to a scar-free anatomy, akin to that seen in stage IV-S NB survival. These data suggest that immune-mediated regression of NB in the liver is possible; whether the result of therapy or spontaneous, the liver histology reverts to normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Inactivation of WT1 in nephrogenic rests, genetic precursors to Wilms' tumour

Nephrogenic rests consist of foci of primitive renal cells, typically microscopic, that are found within the normal kidney tissue of children with Wilms' tumour. To study the relationship between nephrogenic rests and the associated tumours, we screened these lesions for mutations in the 11p13 Wilms' tumour suppressor gene, WT1. In two cases in which the Wilms' tumour contained a somatic WT1 mutation, the nephrogenic rest had the identical mutation. Nephrogenic rests and Wilms' tumours are therefore topographically distinct lesions that are clonally derived from an early renal stem cell. Inactivation of WT1 appears to be an early genetic event which can lead to the formation of nephrogenic rests, enhancing the probability that additional genetic hits will lead to Wilms' tumour.

Association of Down syndrome and segmental tracheal stenosis with ring tracheal cartilages: a review of nine cases

Four patients with Down syndrome and midtracheal stenosis, three with proven absence of the midtracheal pars membranacea ("hourglass trachea"), are reported. Five previously reported patients who had Down syndrome and tracheal stenosis of this type are summarized. Respiratory difficulty and stridor were the reported clinical features of all but one of the patients whose clinical story is available. That approximately half the patients with tracheal stenosis with hourglass trachea and midtracheal absence of the tracheal pars membranacea reported had Down syndrome suggests that the association of this pattern of congenital tracheal stenosis with Down syndrome is, although infrequent, significant.

Free bladder mucosal graft biology: unique engraftment characteristics in rabbits

To study the biology of bladder mucosal grafts we developed an animal model using New Zealand white male rabbits. A 25 x 9 mm. segment of bladder mucosa was harvested and tubularized over an 8F catheter using 7-zero polyglactin sutures. An equivalent portion of rabbit urethra was then excised and the graft was anastomosed to this defect in an end-to-end fashion. A urethral catheter was left in place to provide bladder drainage and to stent the anastomosis. Animals were sacrificed on postoperative days 1 to 90. India ink was injected into the aorta at sacrifice to visualize the microvasculature. All 59 specimens were stained with hematoxylin and eosin, and studied using light microscopy. Our results demonstrated vascular ingrowth at 72 hours. Between postoperative days 8 and 10 healthy viable epithelium first bridged the entire urethral defect. By postoperative day 12 the epithelial lining was complete. A poor outcome was observed in all animals whose stents were removed early. We conclude that the biology of bladder mucosal grafts is unique in that the graft initially undergoes partial degeneration followed by regeneration. Of concern are the results of those animals whose stents were removed early. In all such cases a poor outcome was observed.

Tracheal cartilaginous sleeve

Tracheal cartilaginous sleeve (TCS) is a rare congenital malformation in which discrete cartilaginous rings are replaced by a grossly uninterrupted cartilaginous sleeve. Seven previous patients with TCS have been reported in the world literature; in each instance, TCS was associated with craniosynostosis (CS). We report details of five additional patients with TCS, of whom four had a dominantly inherited CS. Gross examination of the available tracheas and bronchi demonstrates a cartilaginous sleeve with posterior interruption but lacking a normal pars membranacea. The stained and cleared tracheas all demonstrate variable ring formation, usually limited to the posterolateral aspect. The functional significance of TCS, if any, is unknown. No data are available on the prevalence of TCS in CS syndromes. The formation of TCS implies a common mesenchymal defect in which normally discrete structures fuse and is probably analogous to other mesenchymal abnormalities seen in these patients.