The pre-rRNA processing factor DEF is rate limiting for the pathogenesis of MYCN-driven neuroblastoma

The nucleolar factor, digestive organ expansion factor (DEF), has a key role in ribosome biogenesis, functioning in pre-ribosomal RNA (pre-rRNA) processing as a component of the small ribosomal subunit (SSU) processome. Here we show that the peripheral sympathetic nervous system (PSNS) is very underdeveloped in def-deficient zebrafish, and that def haploinsufficiency significantly decreases disease penetrance and tumor growth rate in a MYCN-driven transgenic zebrafish model of neuroblastoma that arises in the PSNS. Consistent with these findings, DEF is highly expressed in human neuroblastoma, and its depletion in human neuroblastoma cell lines induces apoptosis. Interestingly, overexpression of MYCN in zebrafish and in human neuroblastoma cells results in the appearance of intermediate pre-rRNAs species that reflect the processing of pre-rRNAs through Pathway 2, a pathway that processes pre-rRNAs in a different temporal order than the more often used Pathway 1. Our results indicate that DEF and possibly other components of the SSU processome provide a novel site of vulnerability in neuroblastoma cells that could be exploited for targeted therapy.

Diagnostic and surgical challenge: middle ear dermoid cyst in 12 month old with branchio-oto-renal syndrome and multiple middle-ear congenital anomalies

Described is the first case report, to our knowledge, of a middle-ear dermoid in a child with branchio-oto-renal (BOR) syndrome. Radiographic, pathologic, and intraoperative figures are shown. This was a diagnostic and surgical challenge as the presentation was similar to a congenital cholesteatoma and the child had numerous significant temporal bone abnormalities. After the intraoperative findings suggested a non-destructive process, the treatment strategy was altered. This case reiterates the need for a cautious, flexible operative approach in a syndromic child. Included is a relevant review of the literature and a detailed clinical analysis.

Comparative analysis of D2-40 and LYVE-1 immunostaining in lymphatic malformations

Identification of lymphatic vessels in normal tissue and vascular malformations has been considerably enhanced by the recently discovered lymphatic endothelial markers D2-40 and LYVE-1. However, comparative analysis of these two antibodies in the evaluation of lymphatic malformations has not been widely reported. We evaluated twenty lymphatic malformations of skin/subcutis/soft tissue with immunostaining for D2-40 and LYVE-1. Ten high-power fields from each section were scored for total number of immunopositive vessels using identical fields with both markers. Vessels were grouped by diameter (< 225 microm and > 225 microm), with each vessel categorized according to the percentage of its lumen showing immunopositivity (< 25, 26-75, or > 75). Endothelial staining intensity was graded low or high in each case. We found no significant difference between total number of vessels stained with D2-40 or LYVE-1 or between the 2 markers in terms of the percentage of luminal circumference stained or intensity in vessels smaller than 225 microm. LYVE-1 stained a higher percentage of luminal circumference of channels greater than 225 microm at both low and high intensities. Large channels stained much less and sometimes not at all with either antibody. D2-40 and LYVE-1 are both effective for highlighting endothelium of lymphatic malformations, staining similar percentages of channels. LYVE-1 provides more luminal staining in channels larger than 225 microm but is less specific also staining macrophages and adipocytes. Both markers are expressed less strongly or sometimes not at all in large channels.

Vascular tumors of the heart in infants and children: case series and review of the literature

Primary tumors of the heart are rare in children, of which vascular tumors comprise a small subgroup. We present the clinical, histopathologic, and imaging findings in six children with vascular tumors of the heart and review the findings of 36 previously published cases. We observed three intramuscular hemangiomas of the small-vessel type in older children, two congenital hemangiomas in infants, and one malignant polymorphous hemangioendothelioma. Intramuscular hemangiomas did not respond to corticosteroid and were biologically distinct from the congenital hemangiomas, both of which exhibited regression with pharmacotherapy. Age at diagnosis appears to predict histologic type, tumor location, and clinical presentation.

Cardiac, aortic, and pulmonary arteriopathy in HIV-infected children: the Prospective P2C2 HIV Multicenter Study

Arteriopathy in human immunodeficiency virus (HIV)-infected patients is being increasingly recognized, especially in children. However, few studies have histologically evaluated the coronary arteries in HIV-infected children, and none have systematically assessed the aorta and pulmonary arteries. The coronary arteries, thoracic aorta, and the main and branch pulmonary arteries from the postmortem hearts of 14 HIV-infected children were systematically reviewed for vasculopathic lesions and compared with 14 age-matched controls. Findings from the HIV-infected children were compared with clinical, laboratory, and other postmortem findings. Coronary arteriopathy, seen in seven (50%) of the HIV-infected children, was primarily calcific, and it was associated with decreased CD3 and CD4 peripheral blood counts. Large vessel arteriopathy, seen in 9 (64%) of the 14 HIV-infected children, was primarily centered on the vasa vasorum and consisted mainly of medial hypertrophy and chronic inflammation. Large vessel lesions were associated with increased left ventricular mass z-scores (P = 0.02), and 78% of patients with large vessel arteriopathy had postmortem cardiomegaly. Coronary and large vessel arteriopathies are common in pediatric HIV-infection and have different clinicopathologic features suggesting different pathogenesis.

Diagnosis and management of MNGIE syndrome in children: case report and review of the literature

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) syndrome is a rare disorder that presents in childhood; however, marked delay in diagnosis is common. We report a case and review the literature describing the typical features that should alert pediatricians to the diagnosis. We also describe a novel management strategy for providing symptomatic relief.

Comparison of Pkd1-targeted mutants reveals that loss of polycystin-1 causes cystogenesis and bone defects

A high level of polycystin-1 expression is detected in kidneys of all patients with autosomal dominant polycystic kidney disease (ADPKD). Mice that overexpress polycystin-1 also develop renal cysts. Whether overexpression of polycystin-1 is necessary for cyst formation is still unclear. Here, we report the generation of a targeted mouse mutant with a null mutation in Pkd1 and its phenotypic characterization in comparison with the del34 mutants that carry a 'truncation mutation' in Pkd1. We show that null homozygotes develop the same, but more aggressive, renal and pancreatic cystic disease as del34/del34. Moreover, we report that both homozygous mutants develop polyhydramnios, hydrops fetalis, spina bifida occulta and osteochondrodysplasia. Heterozygotes also develop adult-onset pancreatic disease. We show further that del34 homozygotes continue to produce mutant polycystin-1, thereby providing a possible explanation for increased immunoreactive polycystin-1 in ADPKD cyst epithelia in the context of the two-hit model. Our data demonstrate for the first time that loss of polycystin-1 leads to cyst formation and defective skeletogenesis, and indicate that polycystin-1 is critical in both epithelium and chondrocyte development.

Upper respiratory tract carcinoma with chromosomal translocation 15;19: evidence for a distinct disease entity of young patients with a rapidly fatal course

BACKGROUND

Carcinoma of the upper respiratory tract is rare in childhood, and cytogenetic aberrations have not been characterized in this population. The chromosomal translocation 15;19 has been reported four times previously. All patients were young and had tumors arising in the thorax. The three reports that provide clinical follow-up all describe superior vena cava syndrome and death soon after presentation. All tumors were diagnosed as carcinoma (three undifferentiated, one mucoepidermoid), and the authors suggested thymus, lung, or germ cell origin.

METHODS

The authors investigated the clinical and pathologic findings in two patients with poorly differentiated carcinoma showing evidence of t(15;19). This included a 13-year-old girl with a rapidly growing epiglottic mass, leading to superior vena cava syndrome and death and a 12-year-old girl with an aggressive nasopharyngeal mass showing intracranial extension.

RESULTS

The laryngeal tumor was poorly differentiated, with vesicular nuclei, prominent nucleoli, extensive necrosis, and a lymphoplasmacytic infiltrate; cells were positive for cytokeratin and negative for lymphoma, melanoma, germ cell, and endocrine markers. Electron microscopy showed rare intermediate junctions and basal lamina. The nasopharyngeal tumor was poorly differentiated with areas of obvious squamous differentiation observed histologically, immunophenotypically, and ultrastructurally. Cytogenetic and fluorescent in situ hybridization studies were consistent with t(15;19)(q13;p13.1) in both cases. Both children received chemo- and radiotherapy. The first child died of disease after 36 weeks; autopsy revealed tumor in the larynx with spread to the skin/subcutis (neck and thorax) and lymph nodes (cervical, subcarinal, and pulmonary hilar). The second child developed widespread bony metastases and died of disease after 13 weeks.

CONCLUSIONS

In conjunction with previous reports, the authors' findings show that t(15;19) is part of a distinct clinicopathologic entity characterized by young age, midline carcinoma of the neck or upper thorax, and a rapidly fatal course. Female gender and superior vena cava syndrome are common. The histogenesis of these distinctive tumors is unknown. The authors' findings suggest origin in the upper airway, perhaps from submucosal glands.

Gains of chromosome 8 are confined to mesenchymal components in pleuropulmonary blastoma

Pleuropulmonary blastoma, an aggressive tumor that is emerging as a distinct entity of childhood, is characterized by mesenchymal elements (including undifferentiated blastema and often cartilaginous, rhabdomyoblastic, or fibroblastic differentiation) and epithelium-lined spaces. We investigated two patients with pleuropulmonary blastoma, a 3-year-old boy and an 11-year-old girl, both with large cystic masses replacing one lung. In both children, the post-chemotherapy resection specimens showed more maturation of rhabdomyoblasts and more nuclear pleomorphism in all mesenchymal cell lines, compared with biopsies sampled before treatment. Karyotypic analysis demonstrated gains in chromosome 8 in both cases and 17p deletion in one case. Fluorescent in situ hybridization analysis demonstrated that the chromosome 8 gains were present in all mesenchymal elements, including undifferentiated blastematous, rhabdomyoblastic, fibroblastic, and chondroblastic areas. Epithelial cells showed no chromosome 8 gains. The chromosome 8 aberrations were not appreciably different in pre- versus post-chemotherapy tissue. Our findings substantiate previous reports that polysomy of chromosome 8 is a consistent feature of pleuropulmonary blastoma. Further, they indicate that clonal proliferation in pleuropulmonary blastoma is restricted to the malignant mesenchymal elements, supporting the notion that the epithelial components of this tumor are non-neoplastic.

Aggressive multimodal treatment of pleuropulmonary blastoma

Pleuropulmonary blastoma is a rare intrathoracic neoplasm almost solely confined to childhood. Survival is poor. The authors report 2 children with extensive intrathoracic disease who are long term survivors after multimodal therapy. Both children received multiagent neoadjuvant chemotherapy, followed by surgical resection to remove all gross tumor. Postoperative chemotherapy was given to both children; radiotherapy was also given in the second case because of a question of positive tumor margins. Experience supports the use of multimodal therapy, including an aggressive surgical approach in the potentially curative treatment of this tumor.

Giant cell angioblastoma: three additional occurrences of a distinct pathologic entity

Giant cell angioblastoma was described previously in a single case report as a congenital soft-tissue tumor with a unique morphology. In the current report, we describe three cases of giant cell angioblastoma found in three infants; one case was congenital and located in the hand, one appeared neonatally in the palate, and one on the scalp of an infant. Clinical findings and results of light microscopy, immunohistochemistry, and electron microscopy were evaluated. All tumors were ulcerated; the hand and palate tumors also infiltrated soft tissue and bone. They exhibited a solid, nodular, and plexiform proliferation of oval-to-spindle cells with a frequent striking, concentric aggregation around small vascular channels. These cells had characteristics of undifferentiated mesenchymal cells, fibroblasts, myofibroblasts, and pericytes. Co-mingled with these cells were large mononuclear and multinucleate giant cells with histiocytic features. The palatal giant cell angioblastoma, excised with positive margins, was managed with interferon-alpha and showed no progression after nearly 5 years. The hand tumor diminished in size after management with interferon-alpha, was subtotally excised, and did not progress after 27 months. Follow-up data are unavailable for the patient with the scalp lesion. Our findings validate the classification of giant cell angioblastoma as a distinct and rare entity that is locally infiltrative but slow growing. The morphology and diverse cellular differentiation are consistent with an unusual form of neoplastic angiogenesis.

Expression pattern of T-cell-associated chemokine receptors and their chemokines correlates with specific subtypes of T-cell non-Hodgkin lymphoma

Chemokine receptors mediate the migration of lymphocytes through the binding of soluble ligands, and their expression is differentially regulated in lymphocyte subsets. The pattern of chemokine receptor expression in T-cell non-Hodgkin lymphoma has not been previously studied. Using a panel of mouse monoclonal antibodies, we studied the immunohistochemical expression of the Th1-associated chemokine receptor CXCR3 in 141 patients with T-cell lymphoma, and we studied the receptors CCR4 and CCR5 and some of their ligands in a subset of these tumors. Expression of CXCR3 was typical of the smaller T cells in angioimmunoblastic lymphoma (15 of 18 patients), angiocentric lymphoma (3 of 3 patients), histiocyte-rich tumors (4 of 5 patients), and unspecified T-cell lymphomas (17 of 39 patients). CXCR3 expression was seen in only 1 of 15 patients with anaplastic lymphoma kinase (ALK)-positive anaplastic large-cell lymphoma. In contrast, all ALK-positive tumors showed diffuse reactivity for the Th2-associated receptor CCR4 (5 of 5 patients). CCR4 expression was also a consistent feature of the large-cell transformation of mycosis fungoides. CCR5 expression showed no consistent association with any T-cell tumor type. The chemokines Mig (CXCR3 ligand), TARC (CCR4 ligand), and MCP-2 (CCR5 ligand) were detected in intratumoral blood vessels and histiocytes. Mig was also coexpressed by a subset of CXCR3-positive tumor cells in 6 of 20 lymphomas. MCP-2 was highly expressed in stromal cells in 3 patients with nodal involvement by cutaneous T-cell lymphoma. As with normal T-cell subsets, we demonstrated that there is frequent differential expression of chemokine receptors in T-cell tumors, which may explain, in part, the distinctive patterns of spread in different tumor subtypes. (Blood. 2000;96:685-690)

Intraosseus teratoma of the iliac bone

We present a 4-year-old child with a large iliac bone mass incidentally discovered in a plain abdominal radiograph. The pathological examination revealed a benign mature teratoma. To the best of our knowledge, the occurrence of intraosseous mature teratoma has not been previously reported. The child had had an immature teratoma of the neck discovered in a fetal ultrasound, and resected on day 6 of life. The neck teratoma recurred twice, at 16 months and at 3.5 years of age. In these two recurrences the lesion appeared progressively more mature. At the time of discovery of the iliac bone teratoma there was no evidence of residual neck disease. The radiological and pathological characteristics, differential diagnosis, and clinical course are discussed.

The detection of viral genomes by polymerase chain reaction in the myocardium of pediatric patients with advanced HIV disease

OBJECTIVES

The aim of this study was to investigate the frequency of viral nucleic acid detection in the myocardium of human immunodeficiency virus (HIV)-infected children to determine whether an association exists with the development of heart disease.

BACKGROUND

As improved medical interventions increase the life expectancy of HIV-infected patients, increased incidences of myocarditis and dilated cardiomyopathy (DCM) are becoming more apparent, even in patients without clinical symptoms.

METHODS

Myocardial samples were obtained from the postmortem hearts of 32 HIV-infected children and from 32 age-matched controls consisting of patients with structural congenital heart disease and no myocardial inflammation and no cardiac or systemic viral infection. The hearts were examined histologically and analyzed for the presence of viral sequences by polymerase chain reaction (PCR) or reverse transcription-PCR.

RESULTS

Myocarditis was detected histologically in 11 of the 32 HIV-infected patients, and borderline myocarditis was diagnosed in another 13 cases. Infiltrates were confined to the epicardium in two additional hearts. Virus sequences were detected by PCR in 11 of these 26 cases (42.3%); adenovirus in 6, CMV in 3 and both adenovirus and CMV in 2. Two cases without infiltrates were also positive for adenovirus: one had congestive heart failure (CHF) and the other adenoviral pneumonia. No other viruses were detected by PCR, including HIV proviral DNA. All control samples were negative for all viruses tested.

CONCLUSIONS

These data suggest that the presence of viral nucleic acid in the myocardium is common in HIV-infected children, and may relate to the development of myocarditis, DCM or CHF and may contribute to the rapid progression of HIV disease.

Renal cell carcinomas in children and young adults: increased incidence of papillary architecture and unique subtypes

Renal cell carcinomas in children and young adults are rare, and the pathologic features of these tumors have not been well described. We reviewed 24 renal cell carcinomas in children and young adults ages 6 to 29 years, 14 of whom were younger than 18 years of age. Fourteen were female. In 19 (79%) of 24 cases, the tumor met histologic criteria for papillary renal cell carcinoma, with at least 50% papillary architecture. Four of the remaining five cases were typical clear cell tumors in patients known to have von Hippel Lindau syndrome, and one case was of chromophobe type. In the papillary tumors, calcifications, high nuclear grade, extracapsular extension (American Joint Commission on Cancer stage T3), and lymph node metastases were common. Among these papillary tumors, four distinct histologic patterns could be identified. Collecting duct-like tumors (two cases) involved the large collecting ducts, were multifocal and predominantly papillary, and had focal tubular and solid areas. These tumors were reactive for epithelial membrane antigen (EMA) and keratins, including CK7, but negative for Ulex europeaus and high molecular weight keratin 34BE12. Voluminous cell tumors (four cases) were composed of cells with extremely voluminous clear cytoplasm and, although predominantly papillary, had areas that also resembled clear cell tumors. These tumors were reactive for keratins AE1/AE3 but were otherwise negative for all other keratins, EMA, and U. europeaus. One of these tumors showed an X;7 translocation. Adult type tumors (12 cases) resembled papillary tumors of adults. These tumors were reactive for EMA and keratins, including CK7, and all but one were negative for U. europeaus and keratin 34BE12. This last case had trisomies of chromosomes 7, 16, 17, and 20. The final neuroendocrinelike case was multifocal, organoid, and composed of nests of small cells in a neuroendocrinelike pattern. Three of 13 patients were alive with disease at last follow-up, and three additional patients died of disease, all within 2 years. Progression was highly associated with lymph node involvement at the time of resection. We conclude that the clinicopathologic features of renal cell carcinomas in children and young adults differ from those arising in older adults. These tumors are characteristically high-grade, high-stage, papillary tumors with numerous calcifications, and several subtypes can be identified based on histologic, immunohistochemical, and cytogenetic features. Some subtypes appear to be unique to this age group.

Prenatal detection of a solitary liver adenoma

Solitary liver adenomas are rare in children, especially in neonates, and can be difficult to distinguish from other more common liver tumors of newborns and infants. An otherwise healthy male neonate with a prenatal diagnosis of a liver mass underwent ultrasound and MRI followed by resection of the mass. The final histopathological diagnosis was hepatic adenoma. A discussion of the imaging evaluation, differential diagnosis, and literature review is presented.

Lymphadenitis due to nontuberculous mycobacteria in children: presentation and response to therapy

The most common manifestation of infection due to nontuberculous mycobacteria (NTM) in children is cervical lymphadenitis in an otherwise healthy patient. We identified and reviewed 19 cases of proven or presumptive lymphadenitis due to NTM seen at our hospital over the course of 13 months. Nine patients underwent initial surgical excision of involved lymph nodes. Ten children did not have involved lymph nodes excised initially and were treated with macrolide-containing antibiotic regimens. Of these patients, five required subsequent surgical excision and five were cured with combination chemotherapy. Six patients underwent radiographic imaging of the head and neck that revealed asymmetrical adenopathy with ring-enhancing masses but minimal inflammatory stranding of the subcutaneous fat, a finding that may distinguish adenitis caused by NTM from staphylococcal and streptococcal adenitis. Our data suggest that if surgical excision is not considered feasible, antimicrobial therapy for adenitis due to NTM may be beneficial for some patients.

Prenatal detection of a Wilms' tumor

Kidney tumors occur very rarely in utero but when present, they are most often congenital mesoblastic nephroma. A newborn boy was transferred to our hospital with a history of fetal renal mass which proved to be a Wilms' tumor. The clinical history, imaging results, and differential diagnosis are presented with a discussion of neonatal Wilms' tumor. While imaging may not specify the exact diagnosis, it provides staging and anatomic information for the surgeon and the oncologist.

Histopathology of the liver in children with chronic hepatitis C viral infection

Although the epidemiology, natural history, and pathological aspects of chronic hepatitis C are well-defined in the adult population, little is known about the characteristics of chronic hepatitis C infection in children. Reports on the histological features and progression of hepatitis C in children are scarce, and consist primarily of multicenter studies in Japanese and European children. Given the geographic variations in viral genotype and the association of pathology with genotype, whether the Japanese and European studies can be extended to the North American populations is unclear. We report the histopathology of the liver in 40 children with chronic hepatitis C infection treated in a single North American institution. The children included 19 males and 21 females ranging in age from 2.0 to 18.6 years at the time of liver biopsy (mean +/- SD: 11.4 +/- 4.3 years). Our findings indicate that the characteristic histopathological lesions of chronic hepatitis C infection, including sinusoidal lymphocytosis, steatosis, portal lymphoid aggregates/follicles, and bile duct epithelial damage, occur with approximately the same frequencies in children as have been reported in adults. Necroinflammatory activity was generally mild. Portal fibrosis was present in 78% of the specimens, including fibrous portal expansion (26%), bridging fibrosis (22%), bridging fibrosis with architectural distortion (22%), and cirrhosis (8%). Centrilobular pericellular fibrosis, which has not been previously reported in the context of chronic hepatitis C infection in adults or children, was also a prominent feature in our series, occurring with a similar frequency as steatosis or portal lymphoid aggregates/follicles. Our data suggest that in spite of mild histological necroinflammatory activity in general, the stage of fibrosis in children can be severe in spite of relatively short duration of infection.

Minocycline-related autoimmune hepatitis: case series and literature review

BACKGROUND

Minocycline is an antibiotic commonly used in the treatment of adolescent acne.

OBJECTIVES

To describe the clinical, laboratory, and histological features in 3 cases of minocycline-related autoimmune hepatitis and to review the literature of similar cases in the adolescent population.

DESIGN

Case series.

SETTING

Patients were cared for in the Division of Gastroenterology, Children's Hospital, Boston, Mass.

RESULTS

Three adolescents (age, 15-16 years), while being treated with therapeutic doses of minocycline for periods of 12 to 20 months, met the 1993 International Autoimmune Hepatitis Group criteria for autoimmune hepatitis. All had a positive antinuclear antibody titer. Other features included hypergammaglobulinemia and a positive anti-smooth muscle antibody titer. Two patients underwent liver biopsy that revealed severe chronic lymphoplasmacytic inflammation, necrosis, and fibrosis. All other causes of liver disease were excluded. One patient had resolution of symptoms with withdrawal of the drug, while 2 required immunosuppression therapy. A review of the literature yielded only 18 similar cases, none in the pediatric literature, the majority of which contained incomplete pertinent data.

CONCLUSIONS

Minocycline is related to the development of autoimmune hepatitis in some adolescents. Pediatricians who use this drug for treatment of acne should be aware of this serious potential relation and stop the drug immediately when suspicion is raised.

Congenital mesoblastic nephroma t(12;15) is associated with ETV6-NTRK3 gene fusion: cytogenetic and molecular relationship to congenital (infantile) fibrosarcoma

Morphological, cytogenetic, and biological evidence supports a relationship between congenital (infantile) fibrosarcoma (CFS) and congenital mesoblastic nephroma (CMN). These tumors have a very similar histological appearance, and they are both associated with polysomies for chromosomes 8, 11, 17, and 20. Recently, CFS was shown to contain a novel t(12; 15)(p13;q25) translocation resulting in ETV6-NTRK3 gene fusion. The aims of this study were to determine whether congenital mesoblastic nephroma contains the t(12;15)(p13;q25) translocation and ETV6-NTRK3 gene fusion and whether ETV6-NTRK3 fusions, in CMN and CFS, antedate acquisition of nonrandom chromosome polysomies. To address these aims, we evaluated 1) ETV6-NTRK3 fusion transcripts by reverse transcriptase polymerase chain reaction and sequence analysis, 2) genomic ETV6-region chromosomal rearrangement by fluorescence in situ hybridization, and 3) chromosomal polysomies by karyotyping and fluorescence in situ hybridization. We report ETV6-NTRK3 fusion transcripts and/or ETV6-region rearrangement in five of six CMNs and in five of five CFSs. The ETV6-NTRK3 fusion transcripts and/or ETV-region chromosome rearrangements were demonstrated in two CMNs and one CFS that lacked chromosome polysomies. These findings demonstrate that t(12;15) translocation, and the associated ETV6-NTRK3 fusion, can antedate acquisition of chromosome polysomies in CMN and CFS. CMN and CFS are pathogenetically related, and it is likely that they represent a single neoplastic entity, arising in either renal or soft tissue locations.

Cytologic analysis of papillary renal cell carcinoma

BACKGROUND

The papillary variant of renal cell carcinoma has distinctive pathologic and clinical features. Because the prognosis of patients with papillary renal cell carcinoma differs from that of patients with other variants of renal cell carcinoma, accurate diagnosis based on cytologic material may be important for appropriate clinical disease management.

METHODS

A retrospective analysis of cytologic material from 17 papillary renal cell carcinomas and 52 other renal neoplasms with histologic follow-up was performed to identify the relative sensitivity and specificity of different cytologic criteria for papillary carcinoma.

RESULTS

Foamy macrophages and intracytoplasmic hemosiderin were the most sensitive and most specific criteria for the diagnosis of papillary renal cell carcinoma. Foamy macrophages were present in 14 of 17 cases (82%), and intracytoplasmic hemosiderin was present in 13 of 17 cases (76%). Foamy macrophages and intracellular hemosiderin were each present in only 2 of 52 (4%) of nonpapillary tumors examined. Malignant cells were arranged in papillary groups with fibrovascular cores in only 6 of 17 cases (35%), including only 1 of 7 high grade tumors. Nuclear grooves were present in 9 of 17 cases (53%) but were common in only 2 cases. Psammoma bodies were present in only 1 case. Nucleoli and pleomorphism were prominent in high grade tumors. These features, in association with frequent abundant vacuolated cytoplasm, made it difficult to distinguish high grade papillary carcinoma from the clear cell variant of renal cell carcinoma. However, as with low grade tumors, the presence of intracytoplasmic hemosiderin and foamy macrophages were important clues to the diagnosis of 6 of 7 high grade tumors (86%).

CONCLUSIONS

Intracytoplasmic hemosiderin and foamy macrophages are the most sensitive and specific markers for both high and low grade papillary renal cell carcinoma, and they allow for the correct diagnosis in most cases.

Mitochondrial neurogastrointestinal encephalomyopathy: diagnosis by rectal biopsy

A 14-year-old girl with the mitochondrial neurogastrointestinal encephalopathy syndrome had an 8-year history of intestinal pseudoobstruction with abdominal pain, persistent vomiting, gastric and duodenal dilatation, and duodenal diverticulosis. The child appeared chronically malnourished and had severe growth failure. Multisystem involvement was evident with the presence of ptosis, external ophthalmoplegia, muscle wasting, peripheral neuropathy, and diffuse white matter disease seen on magnetic resonance imaging. Lactic acidosis and increased cerebrospinal fluid protein were observed. Mitochondrial enzyme analysis of fresh-frozen skeletal muscle revealed a respiratory chain defect. Molecular genetic studies showed multiple mitochondrial DNA deletions. Pathologic findings in the intestine included atrophy of the external layer of the muscularis propria and an increased number of abnormal-appearing mitochondria in ganglion and smooth-muscle cells. Microvesicular steatosis was observed in liver, skeletal, and gastrointestinal smooth muscle, and Schwann cells of peripheral nerve. Brightly eosinophilic inclusions in the cytoplasm of gastrointestinal ganglion cells were visible by light microscopy, which were confirmed to be megamitochondria by ultrastructural studies. This is the first report of abnormal mitochondria observed in intestinal ganglion and smooth-muscle cells in this syndrome.

Primary malignant epithelial tumors of the liver in children: a study of DNA content and oncogene expression

Primary malignant epithelial tumors of the liver (PMETL) are rare in the pediatric age group, and very little is known about their biology as compared with adult tumors. The prognostic value of the DNA contents measured by image analysis and expression of oncogene c-erb2 and tumor suppressor gene p53 were studied in 30 cases of PMETL in children, including 24 with hepatoblastomas (HB) and 6 with hepatocellular carcinomas (HCC). p53 overexpression was detected in 12 out of 26 cases (46.0%), or in 3 of 5 HCC and 9 of 21 HB cases. A relatively high concordance of staining was observed with the two antibodies used (clone DO7, Dako and clone DO1, Santa Cruz Biotechnology). c-erb-B2 did not yield the characteristic membrane staining in any of the 27 cases in which reliable staining was obtained. However, 1 out of 4 patients with HCC and 1 of 23 with HB revealed strong granular cytoplasmic staining in several neoplastic cells. Interestingly, these were two of the three aneuploid multiploid cases. DNA histograms of 13 out of 29 cases (54.8%) were classified as DNA aneuploid (5/6 HCC and 8/23 HB): nine were hyperdiploid, one was hypodiploid (1HB), and three were multiploid (2HB and 1HCC). In the HB group, DNA aneuploidy was strongly associated with embryonal histological areas, suggesting that a disturbance in the process of cell differentiation is associated with marked genetic aberrations. Only the group of HB was submitted to univariate analysis of survival by the Kaplan-Meier method for age (< 24 months vs. > or = 24 months), sex, preoperative chemotherapy (yes vs. no), residual disease (metastasis, and/or unresectable tumor), p53 expression by immunohistochemistry (positive vs. negative), and DNA ploidy (diploid vs. aneuploid). Only residual disease at the time of diagnosis (P < 0.017) and preoperative chemotherapy (0.030) were found to be negatively correlated with biological behavior, estimated as overall survival. DNA aneuploidy tumors (P < 0.125) and male patients (P = 0.123) showed a trend toward a more aggressive clinical behavior, although the difference was not statistically significant. Combining DNA ploidy and residual disease, patients were categorized into three groups: group I, patients with no adverse prognostic factors, i.e., diploid tumors without residual disease; group II, patients with only one adverse prognostic factor, i.e., aneuploid tumor or residual disease; and group III, patients with both adverse factors, aneuploid tumors and residual disease at time of diagnosis. A log-rank test comparing the three survival curves showed a statistically significant difference between them (P < 0.003). Although the series of cases is small, the results of this study highlight the importance of including DNA ploidy in the protocols designed for HB in children by international cooperative groups.

Enteric duplications of the pancreatic head: definitive management by local resection

BACKGROUND/PURPOSE

Enteric duplications can occur throughout the entire alimentary tract. When they occur in the pancreatic head, they present a formidable challenge in both diagnosis and treatment. Surgical management has ranged from simple drainage to local excision or radical resection (eg, Whipple procedure). The authors propose that with identification of the local anatomic relationships, definitive management can be achieved by complete local resection of the cyst mucosa.

METHODS

The authors have treated four patients, ages 13 months to 4 years for enteric duplication cysts within the pancreatic head.

RESULTS

Clinical presentations were quite varied, including pancreatitis (n = 2), gastritis (secondary to increased production of gastrin), and recurrent pleural effusion with high amylase content. Two of the four cysts had been drained initially using Roux-en-Y cystenterostomies. Our preoperative imaging studies included abdominal ultrasonography, endoscopic retrograde cholangiopancreatography (ERCP), angiography, computerized tomography (CT) or magnetic resonance imaging (MRI) scanning. When necessary intraoperatively, ultrasonography was used for cyst localization and transduodenal pancreatography to define precise ductal relationships. All four duplication cysts were completely excised, including two that communicated directly with the main pancreatic duct. One of the latter extended into the pleural cavity and required a thoracotomy for complete excision. Pathological exam of the excised cysts demonstrated gastric, duodenal, or respiratory mucosa. All four patients have remained entirely asymptomatic during a follow-up of 2 to 7 years postoperatively.

CONCLUSION

The authors conclude that complete local resection of enteric duplication cysts in the pancreatic head can be performed for definitive management, avoiding the complications of more radical procedures.

Ossifying renal tumor of infancy presenting as a palpable abdominal mass

We report a case of ossifying renal tumor of infancy, which presented as a palpable abdominal mass in an otherwise asymptomatic 10-month-old girl. The tumor was partially calcified and occupied the renal pelvis, causing severe hydronephrosis. The differential diagnosis for a patient this age included Wilms tumor, extra-adrenal neuroblastoma, infection, calculus, calcified hematoma and ossifying renal tumor of infancy. The child underwent heminephrectomy and is currently doing well.

Interferon-alpha treatment of chronic hepatitis C virus infection in children

OBJECTIVES

To determine the safety and efficacy of interferon-alpha therapy of chronic hepatitis C virus (HCV) infection in children.

STUDY DESIGN

This was an open-labeled prospective trial of interferon-alpha-2a (IFN-alpha) in children with evidence of HCV infection for at least 6 months. Twenty-three children were enrolled and treated with IFN-alpha at a dosage of 3 million units/m2 three times weekly. Beginning in 1995 patients defined as complete or partial responders after 6 months were offered an additional 6 months of treatment. Endpoints were alanine aminotransferase normalization and loss of hepatitis C viral ribonucleic acid from serum. Responders were compared with nonresponders for age, gender, duration of infection, pretreatment alanine aminotransferase and hepatitis C viral ribonucleic acid levels, saturation of serum iron-binding capacity, histologic score of chronic hepatitis and viral genotype. Statistical methods used for these comparisons included the Kruskal-Wallis test, the Mann-Whitney two-sample test and the Fisher exact test.

RESULTS

Of the 21 children who completed at least 6 months of treatment, 4 (19%) had complete response, 8 (38%) had partial response and 9 (43%) had no response. Three of the 4 complete responders had prolonged treatment; in 2 the response was maintained. One responder relapsed but responded to a second, longer course of treatment. Four of the 8 partial responders had prolonged therapy and 3 of them became complete responders. One child who was originally a nonresponder lost HCV RNA within the first year after therapy. Thus eventually 7 (33%) of 21 patients were complete responders. After at least 12 months of follow-up on most of these children, no relapses have been observed. No differences in any of the variables tested could be demonstrated between responders and nonresponders, but small sample size limits power. IFN-alpha was discontinued in only one child because of side effects, and temporary dosage adjustments were needed in 4 children.

CONCLUSIONS

IFN-alpha is of some efficacy in the treatment of chronic HCV infection in children. Complete or partial responders at 6 months should undergo prolonged treatment.

Small cell sweat gland carcinoma in childhood

Sweat gland carcinomas are rare skin tumors that typically occur in older patients. The spectrum of their clinical and pathologic features is broad, and many different types of sweat gland carcinomas have been described, ranging from fairly indolent to highly aggressive neoplasms. We present two cases of sweat gland carcinoma with a predominant small cell morphology. Both tumors occurred in children. One lesion developed in an 8-year-old girl as an asymptomatic papule on her left forearm, which ultimately was evaluated using biopsy because of rapid growth and change in color. The other lesion occurred on the hand of a 12-year-old boy. Both tumors were pandermal and extended into fat. They were composed of monotonous cuboidal cells with scant cytoplasm that formed tubules and grew in anastomosing cords and trabeculae. The tumor cells were immunoreactive for cytokeratins but not for cytokeratin 20. Ultrastructural analysis (available in one case only) showed that the tumor cells lacked neurosecretory granules. This variant of sweat gland carcinoma needs to be distinguished from other small cell neoplasms of the skin, especially Merkel cell carcinoma, its closest mimic.

Cystic neuroblastoma: emphasis on gene expression, morphology, and pathogenesis

Cystic neuroblastoma (CN) is an unusual variant of neuroblastoma characterized by a grossly visible cyst(s) and almost always distinctive microcysts on light microscopy. Rarely, CN will appear solid grossly, but microcystification will be present. We examined the clinical, pathologic, and biologic features of 17 cases of CN. The majority of CN had been detected by prenatal ultrasound. The tumors were favorable stage, stroma-poor, but with low or intermediate mitotic-karyorhectic indices and had favorable biologic markers reflected by aneuploidy and by an absence of N-myc amplification and chromosome 1p deletions. However, the high trk expression typically identified in good risk tumors was absent. Although the complete natural history of CN is not fully defined, our experience suggests that some tumors progress in size, whereas others may spontaneously regress or mature. The clinical outcome is excellent, as is expected in localized and stage 4S neuroblastoma in infancy.

Congenital myotonic dystrophy pathology and somatic mosaicism

We present the pathology and molecular genetic analysis of an infant with congenital myotonic dystrophy. The proband/infant, born at 35 weeks' gestational age to a mother with myotonic dystrophy and 750 CTG repeats, was markedly hypotonic and had severe cardiomyopathy. She died after 16 days of life. At autopsy, skeletal and heart muscles were immature and had a decrease in contractile elements. DNA CTG trinucleotide repeat analysis of the proband demonstrated 2,480 repeats in blood and a slightly greater number of repeats in skeletal muscles, viscera, and gray matter. Corresponding to the clinical course and pathology, cardiac tissues displayed somatic mosaicism, with repeats ranging from 2,760 to 3,220.

Abnormal bile acid metabolism and neonatal hemochromatosis: a subset with poor prognosis

BACKGROUND

Inborn errors of bile acid synthesis are newly recognized disorders that may cause the phenotypic appearance of neonatal hepatitis or neonatal cholestasis.

METHODS

This is a clinicopathologic study of two sets of siblings with cholestatic neonatal liver failure.

RESULTS

In 3 of the infants, diagnostic evaluation, including analysis of urinary bile salts, revealed a predominance of 7 alpha-hydroxy-3-oxo-4-cholenoic and 7 alpha, 12 alpha-dihydroxy-3-oxo-4-cholenoic acids, a pattern consistent with delta 4-3-oxosteroid 5 beta-reductase deficiency, which could be primary or secondary. The fourth infant died before such testing could be carried out. In addition, all 4 infants had histologically disseminated hemochromatosis and met diagnostic criteria for neonatal hemochromatosis. In the 3 infants studied, histologic examination of the liver disclosed giant cell hepatitis with extensive loss of hepatic parenchyma and rapid progression to cirrhosis. Early treatment with ursodeoxycholic acid and cholic acid, previously reported as effective therapy, was given to 2 siblings; it failed to reverse or halt the liver damage, and both infants died. One infant, with the original diagnosis of neonatal hemochromatosis, was treated with a variety of antioxidants and chelation therapy, as recently reported. No improvement was demonstrated, and he went on to liver transplantation.

CONCLUSIONS

The presentation of delta 4-3-oxosteroid 5 beta-reductase deficiency as neonatal hemochromatosis may represent a distinct subset of this disorder with an accelerated course, no response to therapy and poor prognosis.

Focal glycogenosis of the liver in disorders of ureagenesis: its occurrence and diagnostic significance

Metabolic disorders of ureagenesis can cause a Reye-like syndrome with potentially fatal hyperammonemia in children. A mechanistically heterogeneous subset of these disorders shares the biochemical end-result of impaired mitochondrial citrulline production. These include deficiencies of the mitochondrial enzymes, ornithine transcarbamylase (OTC) and carbamyl-phosphate synthase (CPS), as well as dibasic aminoacidurias hyperammonemia-hyperornithinemia-homocitrullinuria (HHH) and lysinuric protein intolerance (LPI). In this report, we present histopathology of the liver in 10 children with defects of ureagenesis, including 6 with OTC deficiency, 3 with CPS deficiency, and 1 with HHH. The liver showed diffuse microvesicular steatosis, marked periportal nuclear glycogen, and variable portal fibrosis with occasional delicate portal-to-portal bridging. Discrete aggregates of distended hepatocytes with central nuclei and nonvacuolated clear cytoplasm were present in 5 of the 10 children, including two 2 OTC deficiency, 2 with CPS deficiency, and 1 with HHH. Similar aggregates had been previously noted in the liver of some children with OTC deficiency or LPI, but their nature and diagnostic significance had so far remained unknown. Using special stains on frozen tissue sections and electron microscopy, we show that the hepatocytes in these aggregates have little or no cytoplasmic neutral fat, but contain excessive free cytoplasmic glycogen, morphologically mimicking a glycogen storage disease. In our experience, hepatocellular aggregates of this nature do not occur in Reye syndrome or in any of its metabolic mimics other than the subset of defects listed above. Identification of these aggregates on liver biopsy can potentially narrow the differential diagnosis of a Reye-like syndrome with diffuse hepatocellular steatosis.

Pathology of lung allografts in children and young adults

Heart-lung and lung transplantation have become acceptable therapeutic modalities for end-stage lung and heart conditions in children and young adults, but the posttransplantation pulmonary pathology in this age-group is poorly characterized. We present our experience with the pathology of lung transplantation in a cohort of 11 patients with a median age of 12.5 years, and median posttransplantation follow-up of 8.3 months. The findings are based on histological examination of 98 specimens, including five autopsy specimens from patients 20 years of age or younger. Our experience, combined with the data in other pediatric series, suggest that there is not a significant difference in the prevalence or severity of acute rejection or bronchiolitis obliterans (BO) between adult and pediatric lung transplant recipients. Lymphocytic bronchitis/bronchiolitis showed a more prominent association with BO in our series than previously reported in adult studies. Chronic vascular rejection in the pediatric lung transplant recipients can occur earlier than reported in adults and is associated with a grave prognosis. Overwhelming infection was a major cause of death in our experience. In particular, our data combined with the previous reports indicate that adenoviral pneumonia is a relatively common pathogen in the pediatric population and is a major cause of mortality in this age-group.

CD99 (p30/32MIC2) immunoreactivity in the diagnosis of leukemia cutis

The diagnosis of leukemia cutis and distinction of early myeloid cells and blasts from lymphoblasts or other lymphoid cells can be difficult, particularly if only fixed tissue is available. O13, a monoclonal antibody that recognizes CD99, the p30/32MIC2 gene product, has been used to identify a number of cell types, including lymphoblasts, in paraffin sections. To evaluate the usefulness of CD99 immunoreactivity in the diagnosis of leukemia cutis, we analyzed cases of cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma and acute myelogenous leukemia for the presence of this marker. Without the use of antigen retrieval methods, lymphoblasts in cases of cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma were immunoreactive for CD99 in 9 of 9 cases. Myeloblasts and early myeloid cells in cases of cutaneous involvement by acute myelogenous leukemia were immunoreactive for CD99 in 12 (80%) of 15 cases. We conclude that CD99 is a sensitive but nonspecific marker for cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma and that CD99 is immunoreactive in the vast majority of cases (21 [88%] of 24 cases) of leukemia cutis.

Spectrum of tumor angiogenesis in the bone marrow of children with acute lymphoblastic leukemia

It has been shown that solid tumors progress in concert with an induction of tumor angiogenesis. It is not known, however, whether a similar phenomenon occurs in leukemia. Angiogenesis was characterized immunohistochemically by factor VIII staining of bone marrow biopsies and quantified by assessment of microvessel density using previously described techniques. We evaluated bone marrow biopsies from 40 children with newly diagnosed, untreated acute lymphoblastic leukemia. In 22 of the patients, we also evaluated angiogenesis after the completion of remission induction chemotherapy. Control specimens were obtained from children undergoing staging evaluations at the time of diagnosis of solid tumors and lymphomas. Microvessels were counted throughout the entire core specimen in consecutive x 200 fields, and a median count per field (cpf) was calculated. In addition, the number of microvessels in the single x 200 field with the highest microvessel density was designated as the "hot spot." Biopsies from children with leukemia and from controls showed median microvessel densities of 42 and 6 counts per field, respectively (P < or = 0.0001). Microvessel density of the hot spots of leukemia specimens and controls were also significantly different, 51 and 8, respectively (P < or = 0.0001). A computer-aided three-dimensional reconstruction model of bone marrow vascularity showed a complex, arborizing branching of microvessels in leukemic specimens compared with single, straight microvessels without branching in controls. Urinary basic fibroblast growth factor, a potent angiogenic factor, was measured in 22 of the children with newly diagnosed leukemia and in 39 normal, age-matched controls. Urinary basic fibroblast growth factor levels were increased in all 22 patients before treatment, were variable during induction chemotherapy, and demonstrated statistically insignificant decreases at the time of complete remission. These findings suggest that leukemia cells induce angiogenesis in the bone marrow and that leukemia might be angiogenesis dependent and raise the possibility for a role of antiangiogenic drugs in the treatment of leukemia.

Clonal analysis of sacrococcygeal "teratomas"

Congenital masses of the sacrococcygeal region commonly contain multiple tissues and have variously been subclassified as neoplasms or congenital hamartomas based on clinicopathological and embryological observations. We have used a polymerase chain reaction-based assay for nonrandom X chromosome inactivation to infer the clonality of three cogenital sacrococcygeal tumors previously diagnosed as teratomas. One solid immature teratoma was monoclonal, and a predominantly cystic histologically mature mass was polyclonal. A third immature teratoma was noninformative because of baseline asymmetry of polyclonal tissue X inactivation. We confirm that immature teratomas at this site appear to be monoclonal neoplasms and suggest that at least some histologically mature "teratomas" are more appropriately classified as hamartomas.

Cytology of typical and atypical Ewing's sarcoma/PNET

The cytologic appearance of both typical and atypical Ewing's sarcoma (ES)/PNET has been described, but predominantly in small series. The authors reviewed the cytology of 22 cases (5 fine-needle aspirates, 17 intraoperative smears) of confirmed ES/PNET. Fifteen cases had typical cytologic features, including small round cells, scant cytoplasm, round nuclei, fine chromatin, and inconspicuous, but distinct basophilic nucleoli. Two cases were atypical (large cell) variants, with abundant eosinophilic cytoplasm, large irregular nuclei, vesicular chromatin, and prominent eosinophilic nucleoli. Both cases had the immunophenotype of ES/PNET, including reactivity for CD99. Five cases had features intermediate between typical and atypical ES/PNET, including abundant cytoplasm, intranuclear grooves, and pale vesicular nuclei. All cases had the characteristic immunophenotype of ES/PNET, including reactivity for CD99 or demonstrated a t(11;22)(q24;q12) cytogenetically. The authors conclude that although atypical ES/PNET is rare, a significant proportion of cases may exhibit unusual cytologic features. Ancillary studies are recommended to establish the correct diagnosis.

Autoimmune interstitial nephritis and hepatitis in polyglandular autoimmune syndrome

A 6-year-old female with polyglandular autoimmune syndrome type I, chronic active hepatitis, and renal failure is described. The renal biopsy demonstrated advanced tubulointerstitial disease with antibodies directed against tubular basement membranes. The patient's serum contained circulating antibodies directed against both renal and hepatic parenchyma. Renal disease culminating in renal failure and anti-tubular basement membrane disease have not been previously reported in association with polyglandular autoimmune disease. We describe for the first time a patient with polyglandular autoimmune syndrome, chronic active hepatitis, circulating antibodies directed against both renal and hepatic parenchyma, and primary tubulointerstitial disease culminating in renal failure.

Juvenile granulosa cell tumor of the infantile testis. Evidence of a dual epithelial-smooth muscle differentiation

We report the ultrastructure and immunohistochemical profile of seven juvenile granulosa cell tumors of the infantile testis. The infants' ages ranged from 1 day to 11 months. All tumors had characteristics ultrastructure with a mixture of spindle smooth-muscle and theca cells and polygonal granulosa cells. Clusters of polygonal granulosa cells were invested by a continuous basal lamina and contained bundles of distinct cytoplasmic filaments with evenly distributed dense bodies resembling smooth muscle. These filaments were occasionally attached to well-developed, prominent desmosomes. Tumor cells had a conspicuous rough endoplasmic reticulum and Golgi complex and occasional neutral fat droplets. In all tumors, mitochondria had laminated cristae and only rarely were there cristae with a tubulovesicular pattern characteristic of steroid secreting cells. Tumor cells stained focally with low-molecular-weight cytokeratins (8,18, and 19), smooth-muscle-specific actin, desmin, and more noticeably with vimentin. These ultrastructural and immunohistochemical features of dual epithelial-mesenchymal differentiation and distinct muscle-like filaments with dense bodies are characteristic of the juvenile granulosa cell tumor of the infantile testis.

Idiopathic steatohepatitis in childhood: a multicenter retrospective study

OBJECTIVE

To describe the clinical, laboratory, and histopathologic features of idiopathic steatohepatitis in children.

STUDY DESIGN

Retrospective review of all liver biopsies performed at Boston Children's Hospital, Massachusetts General Hospital, and the University of Massachusetts Medical Center from 1991 to 1994. Chart review was performed when biopsies demonstrated steatosis.

RESULTS

Eighty-two patients had biopsy-proven hepatic steatosis. Fourteen patients had fatty liver without evidence of inherited, infectious, autoimmune, endocrinologic, toxicologic, or iatrogenic causes. All 14 patients were obese, averaging 159% of ideal body weight (range, 121% to 222%). Nine patients initially had transient abdominal pain, two had hepatomegaly, and one was identified by incidental laboratory evaluation. These 12 patients had biopsies because of persistent elevations of aminotransferase levels. Two other patients without risk factors for steatosis were identified at staging laparotomy for Hodgkin lymphoma. The 10 boys and 4 girls had an average age of 13.5 years (range, 10 to 18 years). Aminotransferase elevations were modest, with aspartate aminotransferase and alanine aminotransferase values averaging 77 +/- 38 IU and 129 +/- 73 IU, respectively. All had imaging studies demonstrating diffuse fatty change. Histologic examination of biopsy specimens revealed varying degrees of steatosis with inflammation and fibrosis.

CONCLUSION

Idiopathic steatohepatitis occurs predominantly or exclusively in obese peripubertal children. This entity represents a frequent reason for liver biopsy in this age group. The degree of steatosis, fibrosis, and inflammation does not correlate with symptoms or signs, and significant liver injury with bridging fibrosis may be present.

Hepatic adenoma in the pediatric age group. Clinicopathological observations and assessment of cell proliferative activity

The clinicopathological findings of eight children with hepatic adenoma in the absence of cirrhosis are presented. The lesions ranged in diameter from 0.1 to 14.5 cm. Associated disorders were Fanconi's anemia, type I glycogen storage disease. Hurler's disease, and severe combined immunodeficiency with ADA deficiency. The remaining three children had adenoma without known associated disorders. In the children with glycogenosis and Hurler's disease the adenomas were multiple. Significant dysplasia occurred in the two children with Fanconi's anemia; however, the lesions behaved in a benign fashion--one with regression of the tumor after cessation of androgen therapy and the other with nonrecurrence after complete resection. Proliferating cell nuclear antigen (PCNA) labeling index (LI) of the adenoma arising in patients with Fanconi's anemia was significantly greater than the PCNA-LI of adenoma in the other children (mean 4.1% versus 0.9% of nuclei), approaching the lower end of the spectrum for reported hepatocellular carcinoma cases. We emphasize that the worrisome pathology that may occur in hepatic adenoma in children, particularly with Fanconi's anemia, does not necessarily predict malignant behavior. The association of hepatic adenoma with Hurler's disease or severe combined immunodeficiency has not been reported previously.

Congenital fibrosarcoma masquerading as lymphatic malformation: report of two cases

Two infants presented with a congenital cervicothoracic mass; both were initially diagnosed as having lymphatic malformation. A biopsy specimen for one child and excision for the other showed that both lesions were congenital fibrosarcomas. Postoperative chemotherapy was administered to both children. One died within 6 months of incisional biopsy from widespread metastatic disease; the other is still being treated. Congenital fibrosarcoma can be confused in its clinical presentation, radiographic findings, and histopathology with lymphatic malformation (cystic hygroma).

Congenital "neurovascular hamartoma" of the skin. A possible marker of malignant rhabdoid tumor

Distinct congenital, benign, probably hamartomatous, lesions of the upper dermis were noted in two children who subsequently developed malignant rhabdoid tumors. The dermal lesions, which we have named "neurovascular hamartomas" were characterized by a proliferation of capillaries in a background of bland spindle cells with possible neural features. In one child the malignant rhabdoid tumor was located in the kidney, and a synchronous primitive neuroectodermal tumor of the central nervous system was the cause of his death. The other infant had two neurovascular hamartomas, and a malignant rhabdoid tumor arose in contiguity with the deepest portion of the larger of the two hamartomas. An axillary lymph node metastasis rapidly developed in this child followed by widespread metastases and death 3 months later. Neuroectodermal differentiation was observed immunohistochemically or ultrastructurally in all rhabdoid tumors and in the tumor of the brain. This is the first report of a unique congenital benign dermal lesion that appears to be associated with malignant rhabdoid tumors in very young children. A genetic abnormality of neuroectodermal differentiation may underlie the development of these neoplasms.

Unique dermal and subcutaneous botryoid rhabdomyosarcoma associated with mature renal tissue: is this an extrarenal Wilms' tumor?

A unique dermal and subcutaneous botryoid rhabdomyosarcoma admixed with ectopic mature renal tissue, overlying the left lateral lumbosacral region of a 41/2-year-old girl is reported. The tumor was devoid of blastemal or immature epithelial elements and nephrogenic rests. The relationship of this lesion to an extrarenal Wilms' tumor with exclusive myogenous differentiation is discussed.