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Five childhood malignant ectomesenchymomas are reported from three centers in three countries. The children were all younger than 3 years (four less than 12 months), four were boys, and four tumors were sited in the pelvis or external genitalia. All tumors had distinctive light microscopic features of rhabdomyosarcoma and three also demonstrated small numbers of included neuronal cells. Immunohistochemical studies and transmission electron microscopy revealed the additional presence of neurogenic components in the remaining two patients. An additional epithelial component was found by immunohistochemistry in one tumor, which suggests a pluripotential origin that still requires karyotypic investigation. Aggressive chemotherapy and adequate surgical excision have thus far been effective in providing disease-free follow-up for periods of 7 to 50 months. It is implied that because the biological behavior and morphology closely resemble those of rhabdomyosarcoma and because the neurogenic component is often in...

Five childhood malignant ectomesenchymomas are reported from three centers in three countries. The children were all younger than 3 years (four less than 12 months), four were boys, and four tumors were sited in the pelvis or external genitalia. All tumors had distinctive light microscopic features of rhabdomyosarcoma and three also demonstrated small numbers of included neuronal cells. Immunohistochemical studies and transmission electron microscopy revealed the additional presence of neurogenic components in the remaining two patients. An additional epithelial component was found by immunohistochemistry in one tumor, which suggests a pluripotential origin that still requires karyotypic investigation. Aggressive chemotherapy and adequate surgical excision have thus far been effective in providing disease-free follow-up for periods of 7 to 50 months. It is implied that because the biological behavior and morphology closely resemble those of rhabdomyosarcoma and because the neurogenic component is often inconspicuous, many malignant ectomesenchymomas may be misdiagnosed as rhabdomyosarcomas.

A transient form of hypertrophic cardiomyopathy has been previously described in infants of diabetic mothers (IDMs). The purpose of this study was to determine the incidence, natural history and pathologic features of this cardiomyopathy in symptomatic and asymptomatic IDMs. We studied 47 IDMs for evidence of cardiomyopathy. Among 24 symptomatic IDMs, five had marked septal hypertrophy with echocardiographic features suggesting left ventricular outflow obstruction and five had hypertrophy of the right ventricular free wall. With the exception of mild septal hypertrophy, these abnormalities resolved during the first 6 months of life, and echocardiograms in the first-degree family members were normal. Of 23 asymptomatic IDMs, three had septal hypertrophy and two had right ventricular free wall hypertrophy; none of the asymptomatic IDMs had evidence of outflow obstruction. One symptomatic IDM died, and autopsy revealed a hypertrophic septum that distorted both ventricular cavities. Microscopic examination revealed hypertrophic fibers and occasional areas of cellular disarray in the septum. Despite the clinical and pathologic similarities of the cardiomyopathy in IDMs to the hypertropic cardiomyopathies in older children and adults, its transient and nonfamilial nature suggest that it is a separate disease. We speculate that it is a manifestation of the generalized organomegaly in IDMs.

The cause of the sudden infant death syndrome (SIDS, crib death, or cot death) is unknown. Current hypotheses include lability of heart rate and/or rhythm as a pathogenetic factor. The conduction system of 50 infants coming to autopsy were examined by serial sections; the infants were from newborn to two years of age. Twenty-six were SIDS deaths and 24 were explained deaths (ED). The frequency of histologic abnormalities of the specialized tissue was almost identical in both groups of infants. Hemorrhage in or around different parts of the conduction system was present in 27% SIDS and 29% ED. There was no evidence of cell death or degeneration of conduction fibers, nor obstructive lesions of the atrioventricular (A-V) arteries. Apparent moulding of A-V node and His bundle was a universal finding in both SIDS and ED, and consisted of irregular interdigitation of A-V node and His bundle fibers with the myxoid central fibrous body (CFB). Isolated bundles of conduction fibers residing in CFB and membranous ventricular septum were seen in two SIDS, but no direct contact between these fibers and the working myocardium could be identified in serial sections in either case. Without corroborating antemortem electrophysiologic data, the functional significance of morphologic findings in the conduction system of SIDS must remain conjectural.

A high-resolution seismic survey of the Rukwa Rift has imaged the upper 300 m of the Pliocene–Holocene section. The sediments are characterized by aggradational deposition in shallow lacustrine conditions that episodically dried out. Overall the reflection package expands northeastwards towards the Lupa Fault (half-graben bounding fault). Isopach maps for nine intervals (6 m to 65 m thick) show four periods of marked expansion of the section towards the Lupa Fault, interpreted to represent times of fault activity or infilling of fault-created topography during the early stage of fault quiescence. There are three periods of little or much reduced expansion interpreted to represent infilling of the accommodation space between the lake floor and the lake surface during periods of fault inactivity. Cyclicity of such high frequency has not been widely reported for faults which penetrate the crust. The periods of activity show remarkably similar displacement patterns with no lateral migration of the main depocentre, implying that seismic and aseismic slip has persistently clustered in the same parts of the fault. Identification of high-frequency fault cyclicity has implications for sequence stratigraphy in tectonically active areas, since there is a tendency to assume faults do not have cyclic effects on the scale of tens of thousands of years.

A tumor of a 12-year-old boy was studied immunohistochemically by utilizing an extensive battery of antisera against active amines and peptides. The tumor contained argyrophilic cells and resembled fetal lung. The positive immunoreaction in tumor cells for active amines and peptides further supports the probable derivation of the tumor from bronchopulmonary endocrine cells.

The autopsies of 82 patients with cystic fibrosis were reviewed with respect to pathologic changes in the lungs and their respective prevalence among different age groups. Although bronchitis, mucopurulent plugging, and bronchopneumonia were almost universally present among children of all ages, epithelial metaplasia and bronchiectasis were rarer among infants and progressively more prevalent in older age groups. Emphysema was absent in patients under two years of age and affected 11 per cent of the patients two to six years of age and 40 per cent of the patients older than six years, but was never of a severe degree by the point count method. Pulmonary hemorrhage, although uncommon, was usually associated with prominent arterial vessels in walls of bronchiectatic airways. Quantitative assessment of bronchial glands revealed Reid indices significantly higher in patients with cystic fibrosis when compared to noncystic fibrosis patients, but there was no increase in these indices with the age of the patients. Glandular hypertrophy, predominance of mucous acini within glands, and goblet cell hyperplasia of the bronchial mucosa all suggest an explanation for the copious mucous secretion of patients with cystic fibrosis. However, it was not possible to ascertain whether these findings reflect a general exocrine defect of such patients or whether they were merely a response to chronic airway infection, even though the latter is a more plausible assumption.

Pompe's disease (type II glycogenosis), an infantile form of generalized glycogenosis, is characterized biochemically by deficiency of lysosomal acid alpha-1,4-glucosidase and morphologically by intralysosomal glycogen storage in multiple organs, notably the central nervous system, heart, liver, and skeletal muscles. The endocrine system has not been described in detail in the literature. In two infants with Pompe's disease, intralysosomal glycogen was identified in the adrenal cortex and medulla, thyroid gland, parathyroid glands, pancreatic islets, and pituitary gland. Of special interest is the severe glycogen accumulation in the zona fasciculata of the adrenal glands.

In the course of gestation, many bacteria, parasites, and viruses may infect the pregnant woman, but few cross the placenta to affect the fetus and fewer still affect the fetal heart. Although the incidence of fetal cardiac infection is low, the effect on the fetus is major. In terms of frequency, rubella virus, Toxoplasma gondii, and Coxsackie virus B are the principal infectious agents affecting the fetal heart, but any number of organisms may cross the placenta to affect the fetus. The pathogenesis of infection of the fetal heart relates to the agent and to the time of gestation when the infection occurs. The agent affects the heart along one or more of three separate pathways: inhibition of cell growth, cytolysis, and interference with the blood supply. Most agents cause cytolysis, stimulating inflammation and scarring. Although several agents carry the suspicion of teratogenicity, only rubella virus has been incriminated with certainty as capable of functioning along each of the three pathways with the potential to serve as teratogen.

The pancreases from 250 children with fatal infections caused by at least fourteen different viruses were examined for lesions in the islets of Langerhans. Viral cytopathology was found in 4 of 7 cases of Coxsackievirus B infection, 20 of 45 cases of cytomegalovirus infection, 2 of 14 cases of varicella-zoster infection, and 2 of 45 cases of congenital rubella. Destruction of beta cells and acute and chronic inflammatory infiltrates were found in islets from cases with Coxsackievirus B infections. Characteristic inclusion bodies were observed in islets from cases with cytomegalovirus and varicella-zoster infections. This survey provides further evidence that some viruses can infect and damage human beta cells.

In a diamnionic-dichorionic male twin pregnancy, one twin was stillborn, with disseminated cytomegalovirus (CMV) identified morphologically, and the other was liveborn, without clinical or laboratory evidence of CMV infection. The placenta of the affected twin had chronic villitis; that of the liveborn was normal. Although the discordance went unexplained, it illustrates the clinical variability of congenital CMV infection. Dissimilar immune responses between the affected and unaffected twin or direct extension of uterine CMV infection to only one twin may have been responsible for the discordance.