Challenges in the pre- and post-natal diagnosis of posterior fossa cysts: A case report and review of historical evolution of descriptive terminologies.

Background: Radiological diagnoses of posterior fossa cystic abnormalities during antenatal and postnatal periods pose significant challenges as they may have similar early imaging features. Some of the frequently described entities are arachnoid cysts and Dandy-Walker malformations. Blake's pouch cyst is relatively underdiagnosed. The main aim of the study was to explore these diagnostic challenges in the context of various descriptive terminologies and their prognostic implications. Methods: We illustrate this through our case, where fetal magnetic resonance imaging (MRI) at 36 weeks gestation showed small right cerebellum without hydrocephalus or hemorrhage. Possible differential diagnoses included Dandy-Walker malformation or posterior fossa malformations, facial hemangiomas, arterial anomalies, cardiac and eye anomalies, sternal clefting, and supraumbilical raphe. Results: Postnatal sonography noted posterior fossa cyst without hydrocephalus in a normal term infant, who went on to develop symptomatic hydrocephalus by 15 weeks. Computed tomography brain scan confirmed large subtentorial posterior fossa cyst and extensive internal hydrocephalus. Despite emergent ventriculoperitoneal shunt insertion, head circumference continued to rise. MRI scan showed persistent cyst. Subsequently, infant underwent endoscopic fenestration of the cyst with balloon septostomy and now has an age appropriate developmental profile. Conclusion: There is considerable discordance between antenatal and postnatal neuroimaging findings as highlighted in our case. Diagnostic conundrum here was whether this was an arachnoid or Blake's pouch cyst. Differentiating between posterior fossa fluid collections is crucial for management, prognosis, and parental counseling. Close postnatal follow-up is essential to avert complications due to acute hydrocephalus.

Investigating painless rectal bleeding--is there scope for improvement?

INTRODUCTION: Most patients with recurrent painless rectal bleeding warrant endoscopic examination of the lower gastrointestinal tract. This is often limited to rectum or distal colon. The purpose of this study was to compare the diagnostic yield of limited colorectal endoscopy with total colonoscopy in children with recurrent painless rectal bleeding. METHODS: Retrospective review of 314 patients aged 1 to 15 years who underwent colorectal endoscopy for recurrent rectal bleeding. Two hundred six underwent total colonoscopy, whereas 108 patients had endoscopy limited to the rectum in 22, sigmoid colon in 34, descending colon in 43, and transverse colon in 9. Diagnoses were recorded according to the endoscopic and histological findings. RESULTS: After total colonoscopy, a diagnosis was established in 70% of children compared with 35% of those undergoing limited endoscopy (P < .001). This difference was most noticeable in children with inflammatory bowel disease. Juvenile polyps were diagnosed with similar frequency in both groups, reflecting the rectosigmoid distribution of most polyps. CONCLUSIONS: For children presenting with painless rectal bleeding, a diagnosis can be established in the majority if total colonoscopy is performed. This is particularly true for inflammatory bowel disease. Unless a rectal polyp is suspected, full colonoscopy should be planned.