Abstract
A urachal remnant is a rare condition characterized by the persistence of the urachus beyond birth, often presenting with symptoms such as umbilical effusion, periomphalitis, and abdominal pain. Surgical resection is the cornerstone of treatment, but ensuring complete removal of urachal epithelium at the resection margin remains a challenge. This case report focuses on evaluating resection margins of urachal remnants and reports the case of a 25-year-old woman with complaints of umbilical effusion and a mass. She was diagnosed with a urachal remnant and underwent urachal resection and reconstruction, with postoperative confirmation of favorable outcomes and the absence of microscopic hematuria. The intraoperative examination did not reveal any macroscopically clear luminal structure of the urachal resection margin. Subsequent histopathological analysis of the margin using hematoxylin and eosin staining was challenging, prompting the use of immunohistological staining with keratin AE1/AE3 antibody. The antibody did not stain the urachal resection margin, confirming the complete removal of urachal epithelial components. Our study findings suggest the utility of keratin AE1/AE3 staining for assessing urachal remnant margins and underscore the importance of thorough evaluation and complete resection of urachal remnant to prevent recurrence and mitigate the risk of urachal cancer, contributing to improved surgical outcomes and patient care.