Retinoic acid receptor beta variant-related colonic hypoganglionosis.

Retinoic acid receptor beta (RARB) variants are heavily linked to pathologies of neural crest cell migration. The purpose of this report is to present a 23-month-old male with the previously described R387C RARB gain-of-function variant whose gastrointestinal issues and long-term constipation lead to the discovery of colonic hypoganglionosis. This case further delineates the pattern of malformation associated with RARB variants. The findings are also consistent with the known etiology of aganglionic colon due to failed neural crest cell migration.

Pancreatic heterotopia in a neonatal abdominopelvic cyst.

Pancreatic heterotopia is a rare congenital anomaly more commonly incidentally found in adults. While intra-abdominal cysts found on prenatal imaging are not uncommon, we examine a case of pancreatic heterotopia presenting in an abdominopelvic cyst on prenatal imaging. At birth, the neonate was found to have hypoglycemia unresponsive to treatment that resolved after cyst resection. We will review the etiology, imaging findings and clinical course of this anomaly, which should be considered in the differential diagnosis of newborns presenting with unexplained hypoglycemia.

Acalculous candidal cholecystitis after pediatric renal transplant.

AAC caused by Candida is an uncommon entity usually seen in the critically ill. Here, we present the case of an 18-month-old renal transplant patient who developed candidal AAC during the post-operative period. Previous articles have addressed acalculous cholecystitis secondary to a variety of causes, or addressed a wide variety of Candida infections in the biliary tract, but this is the first discussion of cholecystitis caused by Candida without confounding factors such as biliary calculi or multiple pathogens. After the discussion of our patient's case, we also reviewed the English-language literature regarding candidal AAC and discussed diagnosis, treatment, and mortality.

Rhabdomyomatous mesenchymal hamartoma presenting as a skin tag in the sternoclavicular area.

Rhabdomyomatous mesenchymal hamartoma (RMH) is a rare congenital lesion of the dermis and subdermis. It has been described predominantly in newborns, with 30 cases reported in the English literature. Typically, it appears as a skin tag, papule, nodule or a mass involving the face or sternal notch. A 28-day-old girl presented with a 1.4 x 0.8 cm soft skin tag in the right sternoclavicular area. Physical examination revealed no congenital anomalies. A shaved biopsy showed that the core of the lesion contained striated muscle fibers mixed with hair follicles and sebaceous and eccrine glands. Thin epidermis lined the outside of the tag. We report a patient with a RMH in a site not previously reported and discuss the differential diagnosis.

Expression of components of the renin-angiotensin system in autosomal recessive polycystic kidney disease.

Hypertension is a common complication in children with autosomal recessive polycystic kidney disease (ARPKD) who have survived the neonatal period. No information is available regarding the mechanism of hypertension in this condition. The renin-angiotensin system (RAS) is thought to play a role in hypertension associated with the more common autosomal dominant polycystic kidney disease (ADPKD). Occasional reports have documented increased activity of the intrarenal RAS in ADPKD, with ectopic renin expression within cysts and dilated tubules. Because of similarities between ARPKD and ADPKD, we hypothesized that increased intrarenal RAS activity might also be found in ARPKD. We performed immunohistochemical studies on kidney tissues from two infants with ARPKD and two control kidneys. The cystic dilated tubules showed staining with the peanut lectin arachis hypogaea, a marker of distal tubules and collecting ducts, but not with lotus tetragonolobus, a marker of proximal tubules. Strong renin staining was seen in many cysts and tubules of ARPKD kidneys, but only in the afferent arterioles of the normal control kidneys. Angiotensinogen staining was also observed in some cysts and in proximal tubules. Staining for angiotensin-converting enzyme, angiotensin II type 1 receptor, and angiotensin II peptide was present in many cystic dilated tubules. These immunohistochemical studies document for the first time ectopic expression of components of the RAS in cystic-dilated tubules of ARPKD and suggest that overactivity of RAS could result in increased intrarenal angiotensin II production, which may contribute to the development of hypertension in ARPKD.

Renal medullary carcinoma in a six-year-old boy with sickle cell trait.

Renal medullary carcinoma (RMC), an aggressive malignant epithelial neoplasm, first emerged as a distinct clinicopathologic entity in 1995. It affects individuals 40 years of age or younger and is strongly associated with sickle cell disease or trait. The majority of patients with RMC have widely disseminated disease at the time of diagnosis and most fail to respond to both chemotherapy and radiotherapy. Mortality approaches 100%, and death usually occurs within a few months to a year of diagnosis. We report a 6-year-old African-American boy with a history of gross hematuria who died four weeks after diagnosis of disseminated metastatic disease. Autopsy showed a 4.4-cm renal mass with metastases to the contra lateral kidney, liver, lungs and multiregional lymph nodes. RMC should be included in the differential diagnosis of any patient 40 years old or younger with a history of hemoglobinopathy and gross hematuria and/or abdominal or flank pain. A brief discussion of the differential diagnosis, histogenesis and treatment is presented in this study.

Pediatric sinonasal rhabdomyosarcoma: three cases and a review of the literature.

OBJECTIVE: To understand the clinical presentation, management, and natural history of paranasal rhabdomyosarcoma. DESIGN: Retrospective case series review. METHODS: Retrospective medical record review of patients less than 20 years of age who presented to our facility with rhabdomyosarcoma of the nasal cavity or paranasal sinuses. RESULTS: Medical records of all pediatric patients seen in our pediatric otolaryngology clinic were reviewed from January 1, 1995, through December 31, 2000. Three patients were identified with sinonasal rhabdomyosarcoma. Their presentation, evaluation, and treatment were evaluated. Relevant literature 1966 to the present was reviewed with the assistance of Medline. CONCLUSIONS: Rhabdomyosarcoma is an aggressive pediatric malignancy, requiring a high index of suspicion to detect it in its earliest stages. Patients with suggestive symptoms should undergo a full evaluation including nasal endoscopy and imaging. Because the current chemotherapy protocols are more effective on localized disease, early diagnosis is crucial to patient survival.

Glandular inclusions in inguinal hernia sacs: morphologic and immunohistochemical distinction from epididymis and vas deferens.

Glandular inclusions in inguinal hernia sacs may bear a striking resemblance to the epididymis or vas deferens. Misinterpretation as a transected functional structure may raise significant concerns regarding reproductive capability, even if encountered unilaterally. In a child, resolution of these concerns may be years away with the onset of puberty and documentation of normal sperm counts. CD10 has been shown to be present in Wolffian-type epithelium and to be absent in Mullerian-type epithelium. We hypothesized that an antibody to CD10 would react with vas deferens and epididymis and fail to react with hernia sac inclusions, most of which we thought were Mullerian duct-derived structures. Glandular inclusions in 29 hernia sacs from prepubertal males were classified histologically according to their resemblance to normal structures and analyzed for CD10 by immunohistochemistry. Inclusions resembling vas deferens had their external diameters measured and were also stained for smooth muscle actin. Thirty-one examples of normal vas deferens and 13 examples of normal epididymis were included for comparison. The inclusions were classified as vas deferens-like (9), epididymis-like (13), and Mullerian-like (7). CD10 reactivity was lacking in all vas deferens-like inclusions; their median external diameter was 0.6 mm. Of the epididymis-like inclusions, 7 of 13 were CD10 positive. The CD10-negative cases consisted of glands with well-defined stromal coats distinct from adjacent stromal coats. CD10-positive cases were more numerous, more tightly aggregated, and surrounded by less well-developed stromal coats that blended with adjacent coats. All seven Mullerian-like remnants were CD10 negative. All normal vas deferens and epididymis showed at least focal CD10 reactivity. CD10 positivity in all cases had a luminal membranous staining pattern. Both the vas deferens-like inclusions and the normal vas deferens showed strong smooth muscle actin positivity in their stromal coats. CD10 negativity and external diameter <1 mm are highly useful to distinguish vas deferens-like inclusions from true vas deferens. Epididymis-like inclusions are more problematic. Some react for CD10 and may represent aberrant Wolffian ductules. Others are CD10 negative, distinct from true epididymis, and may be of Mullerian differentiation. Mullerian-like remnants can be diagnosed on the basis of their limited number and scattered distribution. Lack of CD10 immunostaining corroborates this interpretation.