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Objectives/Hypothesis: The human cochlea is most commonly considered to have two and a half turns. Although the causes of cochlear hypoplasia are well described, cochlear hyperplasia is a rarer entity that is poorly understood. We describe rare anatomic cochlear malformations identified in a 4-month-old male originally referred for evaluation after a failed newborn hearing screening. The full diagnostic evaluation, imaging findings, treatment, and follow-up are described in detail. Cochleae with three turns are an uncommon malformation that is not included in current classifications schemes and may represent a distinct type of anomaly not caused by developmental arrest. [ABSTRACT FROM AUTHOR]

Congenital pulmonary airway malformation (CPAM) is a developmental disorder. Types 1-2-3 are the more common ones. Atypical goblet cell hyperplasia (AGCH) in CPAM might be a precursor lesion for pulmonary adenocarcinomas. In nine out of 33 CPAM cases, types 1-3 showed foci of goblet cell proliferations. As these cells completely replace normal epithelium, we prefer to name these proliferations AGCH. In 5 cases, adenocarcinomas were seen (AC). All cases were analyzed for proteins possibly being associated with CPAM development: fibroblast growth factor 10 (FGF10) and receptor 2 (FGFR2), forkhead box A1 (FOXA1) and A2 (FOXA2), MUC protein 5AC (MUC5AC), human epidermal growth factor receptor 2 (erbB2, HER2/neu), hepatocyte nuclear factor 4α (HNF4α), SOX2, and Ying Yang protein 1 (YY1). By next generation sequencing, AGCH and adenocarcinomas were evaluated for driver mutations. Expression for FGF10, FGFR2, FOXA1, and FOXA2 was seen in CPAM epithelium and stroma, but not differently in AGCH and AC. SOX2 was positive in CPAM epithelium and AGCH, however weakly in AC. YY1 and MUC5AC showed more intense staining in AGCH and AC than in CPAM epithelium. HER2 was intensely expressed in AC and less intensely in AGCH, but not in CPAM epithelium. KRAS mutation in exon 2 was detected in all AGCH and AC, but was absent in CPAM epithelia. AGCH can arise in CPAM types 1-3. Oncogenic KRAS mutation seems to be the oncogenic driver already in AGCH, proving its role as a precursor lesion for adenocarcinoma. It might upregulate HER2 at the protein level. YY1 seems to be involved in carcinogenesis.

Aberrant Muscle Syndrome (AMS) is a rare congenital hand difference that is characterised by unilateral non-progressive muscular hyperplasia. The aetiology of aberrant muscle syndrome is not known, but a recently published case has shown a somatic PIK3CA activating mutation in a patient with AMS. Carpal tunnel syndrome (CTS) in children is rare. The most common causes are the mucopolysaccaridoses but space-occupying lesions have also been reported to cause CTS in children. We report the first case of CTS in a child with AMS successfully treated with open carpal tunnel release and excision of aberrant muscles.

Medullary sponge kidney (MSK) is a congenital renal disorder. Its association with several developmental abnormalities in other organs hints at the likelihood of some shared step(s) in the embryogenesis of the kidney and other organs. It has been suggested that the REarranged during Transfection (RET) proto-oncogene and the Glial cell line-Derived Neurotrophic Factor (GDNF) gene are defective in patients with MSK, and both RET and GDNF are known to have a role in the development of the central nervous system, heart, and craniofacial skeleton. Among a cohort of 143 MSK patients being followed up for nephrolithiasis and chronic kidney disease at our institution, we found six with one or more associated non-renal anomalies: one patient probably has congenital hemihyperplasia and hypertrophic cardiomyopathy with adipose metaplasia and mitral valve prolapse; one has Marfan syndrome; and the other four have novel associations between MSK and nerve and skeleton abnormalities described here for the first time. The discovery of disorders involving the central nervous system, cardiovascular system and craniofacial skeleton in MSK patients supports the hypothesis of a genetic alteration on the RET-GDNF axis having a pivotal role in the pathogenesis of MSK, in a subset of patients at least. MSK seems more and more to be a systemic disease, and the identification of extrarenal developmental defects could be important in arousing the suspicion of MSK in recurrent stone formers.

Alveolar capillary dysplasia (ACD) is a rare and lethal cause of hypoxic respiratory failure in the neonate. Here we describe a term neonate with ACD that was found with a previously unreported p.Arg86Pro mutation in the FOXF1 (Forkhead Box-F1) gene and coexisting congenital anomalies, including colobomas of the iris and hemihyperplasia. This unique clinical presentation may indicate a novel, yet unconfirmed disease association for mutations in the FOXF1 gene. Rapid mutation analysis in FOXF1 may provide noninvasive early confirmation of ACD in neonates with respiratory failure and can aid in clinical decision making.