Appendiceal Mucinous Neoplasm in a De Garengeot Hernia: A Case Report

De Garengeot's hernia, a femoral hernia containing an incarcerated appendix, is rarely encountered in clinical practice. We report a case of a 62-year-old woman presenting with a right groin lump. A computed tomography scan reported a right inguinal hernia containing fluid with no bowel involvement. Exploration of the right groin revealed a femoral hernia containing an inflamed appendix. Appendicectomy and suture repair of the femoral canal were performed, with histology showing a low-grade appendiceal mucinous neoplasm, which is also rare. After a discussion during the colorectal multidisciplinary team meeting and taking into consideration the patient's wishes, a decision was made regarding a complete right hemicolectomy. Histology from the subsequent surgery did not demonstrate any adverse features, and the patient was enrolled in the surveillance program. This case highlights the rarity of this finding and underscores the importance of tailoring surgical approaches based on the intraoperative findings aided by preoperative imaging and a thorough understanding of the anatomy.