Perspectives in pediatric pathology最新文献

Lesions from the SC region of children examined histologically at the RAHC were: 1. Malformations almost always associated with spina bifida aperta or occulta: 183 myelomeningocele (MM), 32 meningocele (M), 35 lipoMM and lipoma, 19 dermoid cyst, six occult meningocele, two Pacinian hamartoma, one short filum, four hindgut cysts or sinuses, two tailgut cysts, and two epithelial heterotopia. 2. Neoplasms, usually without spina bifida: 56 teratomas (11 malignant), five ependymomas (two purely subcutaneous), and 14 miscellaneous primary malignancies, (most neuroblastoma and rhabdomyosarcoma). Distinction between MM with glial tissue and M without glial tissue is important as M had a much better prognosis, less than a third developing hydrocephalus, and 77% walking unaided. Of those with glial tissue, the eight without Arnold-Chiari malformation were myelocystocele associated with cloacal exstrophy (six), caudal regression syndrome (one), and microcephaly (one). Postsacral glial tissue without paraplegia may occur with a subcutaneous vestige of filum terminale, or with herniation of the nonfunctioning half of a diplomyelia. Of postsacral "lipomas" and dermoids, 70% had an intraspinal connection through an occult spina bifida. This posterior vertebral defect is easily overlooked as the arches normally may not ossify until after 6 years. Therefore, the pathologist receiving a postsacral specimen may wish to alert the clinician to the high incidence of late effects from an occult intraspinal component or tethering of the spinal cord. Transsacral hindgut herniations and cysts probably result from ectoendodermal adhesions. Presacral multicystic malformations with mixed squamous and mucus cell lining are probably tailgut remnants or anorectal duplications, and may be mistaken for dermoid or teratoma. In SC teratoma in infants, contrary to some reports on ovarian teratoma in adults, immature tissues do not indicate a worse prognosis. Malignancy is virtually confined to teratomas including a carcinomatous or "yolk sac" component. It is more common in predominantly presacral examples and rare before the age of 4 months. SC ependymoma differs from ependymoma elsewhere in that it may be primary outside the craniospinal cavity (presacral or postsacral), may have a myxopapillary pattern special to the region, and although low-grade and slow growing, is more likely to metastasize beyond the central nervous system. Postsacral examples arise from vestiges of the filum terminale which are normal in the subcutis there. Combinations of all these lesions occur with vertebral defects and with each other.(ABSTRACT TRUNCATED AT 400 WORDS)

Most of the clinical problems experienced by the IDM in the immediate neonatal period are manifestations of abnormal fetal developmental physiology that occur in response to an increased flux of glucose from mother to fetus. The principal fetal responses are hyperglycemia, hyperinsulinemia, increased metabolic rate, and hypoxemia. Those fetal responses very likely lead to a redistribution of cardiac output, increased release of norepinephrine, and blunted release of glucagon. More fat is stored in adipocytes; more glycogen is stored in the liver; the heart may develop asymmetric septal hypertrophy; and lung metabolism is altered to delay the appearance of mature surfactant. At birth, the macrosomic IDM develops hypoglycemia that has a multifactorial basis (hyperinsulinemia, hypoglucagonemia, and probably diminished gluconeogenic and cortisol production rates). The IDM may experience respiratory symptoms from one of three causes: IRDS, persistent pulmonary hypertension, or congestive heart failure. Hyperbilirubinemia may occur because of increased rate of hemolysis; hypocalcemia and hypomagnesemia are likely within the first 3 days in association with a sluggish PTH response; and abnormal levels of inhibitors of fibrinolysis and platelet prostaglandin E-like substances may stimulate abnormal thrombosis.

Five infants with a rare and distinct malformation complex were encountered in a single community within a 7 1/2-month period. Only seven previous reports of this condition were found in the 54-year period between 1926 and 1980. The principal findings in the previously published cases were absence of external genitalia, urinary, genital, and anal orifices, and persistence of the cloaca. This report documents the occurrence of the syndrome in a temporal and regional cluster. Detailed morphologic evaluation of each infant provides the basis for a theory of embryogenesis of the complex, and preliminary data suggest a teratogenic cause. Embryonic exposure to doxylamine succinate within the first 50 days of the pregnancy was certain in three and was probable in two of the five pregnancies.

The human immune system has evolved multiple cellular and humoral defense mechanisms against the lymphotropic virus, EBV. NK cells, suppressor T-cells, cytotoxic K-cells, memory T-cells, and humoral immune responses usually subdue the virus into latency. Individuals with immune deficiency are at great risk of developing immunoregulatory disturbances and lymphoproliferative diseases when confronted by EBV. The infection of B-cells by EBV provokes a marked activation of immunoregulatory T-cells and requires restoration of immune homeostasis during convalescence. This is accomplished with difficulty in an individual with significant immune defects. The X-linked lymphoproliferative syndrome is an exemplary model for studying EBV in immune deficient individuals. Boys with XLP can develop acquired agammaglobulinemia, aplastic anemia, chronic or fatal IM, and a variety of B-cell malignant lymphomas following infection by the virus. We have identified multiple immune defects in the patients and progressive immunoregulatory disturbances following infection by the virus. Other patients with immune deficiency syndromes, i.e., ataxia telangiectasia or the renal transplant recipient, are also at increased risk for developing EBV-induced lymphoproliferative diseases. Moreover, certain families are at increased risk for EBV-associated malignancies, especially those with a triad of manifestations (i.e., autoimmunity, immunodeficiency, and lymphoma). Chromosomal breakage as seen in patients with ataxia telangiectasia may predispose to leukemogenesis. Immunoregulatory defects are also probably predisposing factors to lymphomagenesis. Both inherited and acquired defects can render persons vulnerable to leukemia and lymphoma.