"Double-muscle" trait in cattle: a possible model for Wiedemann-Beckwith syndrome.

The Wiedemann-Beckwith syndrome (WBS) was first described in 1963 as a group of anomalies involving primarily macrosomia, macroglossia, and omphalocele. Histologic studies of WBS show nesidioblastosis of the pancreas, adrenocortical cytomegaly, and persistent metanephric blastema of the kidney. Multiple lines of evidence indicate that the human 11p15.5 region is the locus of abnormality in WBS. Insulin-like growth factor II (IGF-2) frequently has been considered a candidate gene, and expression of IGF-2 is known to be significantly delayed in fetal skeletal muscle of double-muscle (DM) cattle. Other candidate genes recently have been proposed for WBS. A number of recessive alleles in the bovine myostatin gene (GDF8, mapped to bovine chromosome 2 and apparently orthologous to the human 2q22 region) have been shown to be responsible for DM. Recently the first human case of deficient GDF8 function has been reported, confirming the importance of this gene. Bovine IGF-2 has been sequenced and localized to chromosome 25. The primary purpose of this study was to compare and contrast histologic findings in DM and WBS. Immunohistochemical staining confirms changes similar to nesidioblastosis in the pancreas. Other dysplastic changes of a cystic nature are seen in the adrenal. The renal histology of DM fetuses did not appear significantly different than controls.

Twin-twin transfusion syndrome in a dizygotic monochorionic-diamniotic twin pregnancy.

We present a case of twin-twin transfusion syndrome with discordant gender. Monochorionicity was confirmed by surgical pathology. Cytogenetic analysis showed normal 46,XX and 46,XY karyotypes. Microsatellite analysis using reliable pericentromeric markers was consistent with dispermic fertilization of two separate ova. This suggests that monochorionicity, rather than zygosity, may be responsible for the development of placental vascular anastomoses.

Ultrasound prenatal diagnosis of fetus in fetu.

A case of fetus in fetu was diagnosed prenatally using ultrasound. The differential diagnosis between a fetus in fetu and a highly differentiated teratoma is discussed. The importance of prenatal diagnosis of fetus in fetu and the effect on subsequent management are described.

Smooth muscle cell depletion and collagen types in progeric arteries.

Review of two autopsy cases of progeria confirms severe smooth muscle cell (SMC) depletion in the atherosclerotic aortic media and the presence of collagen types I, III, IV, V, and VI in the aorta and renal vessels as is consistent with atherosclerotic disease.

Pathology quiz: small cell osteosarcoma.

A 15-year-old black male presented with shortness of breath, leg weakness, and pain in his back and rib cage. Four years previously he had noticed a lump in his upper back and complained of pain when playing basketball, especially on contact to that area. Recently, the pain had become more constant and increased in intensity. This was associated with loss of control in his legs, weakness, and paraesthesia. General physical examination revealed a palpable mass in the right midline upper back. Laboratory results were within normal limits. Radiographic scans demonstrated a destructive soft tissue mass at T6 vertebral body with scattered stippled calcification (Figure 1). The patient underwent a biopsy followed by excision of the mass (Figure 2) and decompressive laminectomy with reconstruction.

Megacystis-microcolon-intestinal hypoperistalsis syndrome and aganglionosis in trisomy 18.

Ultrasonography at 23 weeks of gestation documented the presence of megacystis with horseshoe kidney, microcolon, intestinal malrotation, and decreased amniotic fluid volume. After pregnancy termination, an autopsy was performed. The external phenotype was diagnostic of the trisomy 18 syndrome confirmed by chromosome examination. The fetus also had a massively distended bladder with parchment-thin wall, microcolon, intestinal malrotation but no urethral obstruction or hydronephrosis. No ganglion cells were present in the colon or bladder. This has not been mentioned in other reported cases and, therefore, suggests pathogenic heterogeneity. The megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare autosomal recessive condition of unknown pathogenesis whose genes map to 15q24. Thus, its previously undescribed presence in trisomy 18 further suggests etiologic heterogeneity.

Evidence for the "midline" hypothesis in associated defects of laterality formation and multiple midline anomalies.

A male infant was liveborn at 38 weeks of gestation to a G4P1AB2, 22-year-old, mother. Polyhydramnios and multiple congenital anomalies were noted by ultrasonography; the infant died 5 min after birth. At autopsy, the infant had multiple defects of blastogenesis including midline anomalies with asplenia and abnormalities of laterality formation. The laterality defects were unusual in that they combined asplenia with hypoplastic, symmetrically unilobate lungs and bilateral hyparterial bronchi more consistent with polysplenia, abdominal situs inversus with midline stomach, symmetric liver, and left gallbladder. No intracardiac abnormalities were present, but there was azygous continuation of the inferior vena cava. Additional multiple midline defects included bronchoesophageal fistula, duodenal atresia, absence of posterior leaf of diaphragm; horseshoe adrenal gland; microcephaly; Dandy-Walker anomaly with agenesis of cerebellar vermis and occipital encephalocele; holoprosencephaly with orbital encephalocele, midline defect of the orbital plate of the skull, bilateral anophthalmia, double proboscis with bilateral choanal atresia, midline upper lip and palatal cleft; single-lobed thyroid; hypoplastic external genitalia with midline cleft of scrotum, long tapering fingers, and defects of the cranium at the sites of orbital and occipital encephaloceles. Defects of laterality frequently are associated with other complex midline anomalies, which both result from a disturbance of pattern formation during blastogenesis, i.e., the induction of the progenitor fields. The latter are the result of the establishment of upstream expression domains of growth and transcription factors and other morphogens. Many of these and other genetic systems, expressed asymmetrically around the midline, are responsible for laterality formation and are the result of upstream and subsequent downstream gene expression cascades through the expression of genes such as HOX genes; bFGF; transforming growth factor beta/activins/BMP4; WNT-1,8; and SHH.

Multiple meningiomas, craniofacial hyperostosis and retinal abnormalities in Proteus syndrome.

Because clinical evidence suggests that Proteus syndrome may be caused by a somatic mutation during early development, resulting in mosaicism, the possible types of abnormalities and their clinical distributions are highly variable. Here, we report on an unusual patient with Proteus syndrome. Manifestations included multiple meningiomas, polymicrogyria, and periventricular heterotopias. Both eyes had epibulbar cystic lesions. The retina showed diffuse disorganization with nodular gliosis, retinal pigmentary abnormalities, chronic papilledema, and optic atrophy. Other abnormalities included progressive cranial, mandibular, maxillary, and auditory canal hyperostoses, epidermal nevi, and mental deficiency. The limbs were proportionate, and the hands and feet were normal.

Abnormal umbilical cord coiling is associated with adverse perinatal outcomes.

The normal umbilical cord coil index is one coil/5 cm, i.e., 0.2 +/- 0.1 coils completed per cm. We report the frequency and clinical correlations of abnormally coiled cords among 1329 cases referred to our placental pathology services. Twenty-one percent of cords were overcoiled and 13% were undercoiled. Abnormal cord coiling was seen at all gestational ages. Principal clinical correlations found in overcoiled cords were fetal demise (37%), fetal intolerance to labor (14%), intrauterine growth retardation (10%), and chorioamnionitis (10%). For undercoiled cords, the frequencies of these adverse outcomes were 29%, 21%, 15%, and 29%, respectively. Abnormal cord coiling was associated with thrombosis of chorionic plate vessels, umbilical venous thrombosis, and cord stenosis. Thus, abnormal cord coiling is a chronic state, established in early gestation, that may have chronic (growth retardation) and acute (fetal intolerance to labor and fetal demise) effects on fetal well-being. The cause of abnormal cord coiling is not known. Its effects on neurological status of survivors are also unknown. Antenatal detection of abnormal cord coil index by ultrasound could lead to elective delivery of fetuses at risk, thereby reducing the fetal death rate by about one-half. We recommend that the cord coil index become part of the routine placental pathology examination.

Ocular manifestations in Proteus syndrome.

We report on the ocular manifestations of a Proteus syndrome patient. Several of the manifestations are due to severe maldevelopment and malfunction of the neuroretina including strabismus, nystagmus, high myopia, and retinal pigmentary abnormalities. In reviewing the literature, strabismus and epibulbar tumors were recorded most commonly. Some articles about presumed Proteus syndrome are spurious; these have not been included here. Also, because of anecdotal and nonsystematic study of the eye and because of the ascertainment bias inherent in literature reports, numbers of cases of each ocular manifestation have not been tabulated.