Blake's pouch cyst is a rare posterior fossa cystic lesion characterized by posterior ballooning of the superior medullary velum into the cisterna magna. It must be differentiated from severe malformations like inferior vermian hypoplasia and Dandy Walker malformation. We describe a case in which a diagnosis of Blake's pouch cyst was made on prenatal ultrasound and later confirmed by MRI. The c...

We describe two infants in whom rhombencephalosynapsis was diagnosed with MR imaging in vivo. In contrast to Dandy-Walker malformation, the vermian maldevelopment in this anomaly is characterized by an absence of the anterior vermis and a deficiency of the posterior vermis. The cerebellar hemispheres are fused. In an attempt to identify the pathogenesis of these anatomic manifestations, we ques...

PURPOSE To determine whether the MR findings of callosal dysgenesis suggest that the partially formed corpus callosum in humans is the result of arrested growth or delayed continued development. METHODS The MR scans of 25 patients with callosal dysgenesis were reviewed to determine whether the observed corpus callosum corresponded to the form and position of a portion of a normal corpus callo...

The Y-chromosome-located SRY gene encodes a small testis-specific protein containing a DNA-binding motif known as the HMG (high mobility group) box. However, mutations in SRY are not frequent especially in cases of 46,XY partial gonadal dysgenesis. Several sex-determining genes direct the fate of the bipotential gonad to either testis or ovary. In addition, heterozygous small deletions in 9p ca...

RIEGER'S dysgenesis mesodermalis iridis et corneae, caused by a faulty differentiation in the anterior segment, is not limited to the mesodermal structures of the eye, but demonstrates a range of ectodermal anomalies as well. This is why Hagedoorn (1937) suggested the term "dysgenesis mesostromalis", stressing the frequent occurrence of ectodermal developmental anomalies of the iris and lens, c...

46, XY complete gonadal dysgenesis (Swyer syndrome) is a rare cause of 46, XY sexual development disorder. The patient presented to our clinic with absence of breast development and lack of periods at the age of 17 years. Her history and familial history involved no relevant conditions. She had Tanner stage 1 thelarche, and Tanner stage 2 pubic hair development with no axillary hair development...