The Cloacal Interest Group: From clinical observation to translational science

The study of cloacal exstrophy has traditionally relied on detailed anatomical observations derived from clinical practice. In the 1980s, a collaborative review of 34 cloacal exstrophy cases led to the development of a novel grid-based system that transformed descriptive anatomy into a structured framework for phenotypic classification and revealed important relationships between bowel, bladder, and genital development. Nearly four decades later, this unique archival collection was rediscovered and recognized as a valuable resource for modern translational investigation. A pivotal interaction between pediatric urologists at an American Academy of Pediatric Urologists (AAPU) meeting led to the formation of the Cloacal Interest Group, bringing together clinicians, developmental biologists, geneticists, pathologists, embryologists, and comparative bioscientists. By integrating historical clinical observations with advances in developmental biology, genetics, imaging, and tissue analysis, the group expanded its focus from cloacal exstrophy to the broader spectrum of cloacal malformations. Key accomplishments include the development of a standardized anatomical biopsy map, reproducible tissue-sampling coordinates, and a shared anatomical framework linking human specimens with experimental developmental models. This narrative highlights how historical clinical archives, interdisciplinary collaboration, and generational exchange can transform descriptive anatomy into a platform for mechanistic investigation and future discoveries in cloacal development and malformations.