Appendix Testis Torsion

Torsion of testicular appendages is the most common cause of acute scrotal pain in prepubertal boys and a leading cause of pediatric orchalgia. Therefore, it should be routinely considered in the differential diagnosis of any pediatric male presenting with acute scrotal symptoms. Two distinct vestigial structures may undergo torsion—the appendix testis and the appendix epididymis. The appendix testis, also known as the hydatid of Morgagni, is a Müllerian duct remnant present in approximately 76% to 83% of testes. Typically located at the superior pole of the testis between the testis and epididymis, the appendix testis is the appendage most commonly involved in torsion.This structure is homologous to the female's fimbriated end of the Fallopian tube. The appendix epididymis, derived from the Wolffian (mesonephric) duct, is identified in roughly 22% to 28% of testes and lies along the head of the epididymis. This structure is sometimes regarded as a detached efferent duct. Accurate clinical and ultrasonographic differentiation of testicular appendage torsion from epididymo-orchitis, testicular torsion, and other causes of acute scrotum is essential to prevent unnecessary surgical exploration, minimize morbidity, and facilitate timely, evidence-based management. Recognition of characteristic features can help establish the diagnosis and guide conservative management. Recent pediatric data highlight the importance of standardized diagnostic algorithms, targeted parental education, and expedited referral pathways, collectively reducing preventable testicular loss and its associated medicolegal consequences. Ultimately, a coordinated multidisciplinary approach remains essential to ensure timely recognition and evidence-based management of suspected testicular appendage torsion.