Bilateral Inguinal Hernia With Psoas Muscle Involvement: A Case Report and Literature Review.

Inguinal hernia is one of the most common conditions in general surgery; however, atypical variants extending beyond the conventional myopectineal boundaries are infrequently encountered. Herniation involving the psoas muscle is exceptionally rare due to its deep retroperitoneal location and is often identified only during surgical exploration. We report the case of an 86-year-old woman who presented with persistent right inguinofemoral pain without a palpable groin mass. Preoperative evaluation, including prior cross-sectional imaging, did not demonstrate a definitive inguinal defect. Owing to sustained symptoms and clinical suspicion, elective laparoscopic transabdominal preperitoneal (TAPP) repair was performed. Intraoperative exploration revealed an unusual deep hernia tract on the right side extending posteriorly into the retroperitoneal plane adjacent to the psoas muscle. On the contralateral side, protrusion of preperitoneal fat without a well-defined hernia sac resulted in an asymmetric bilateral presentation. Careful reduction of the retroperitoneal extension and contralateral preperitoneal tissue repositioning were followed by bilateral mesh reinforcement. The procedure was completed without complications. At one-month follow-up, the patient remained asymptomatic with no evidence of recurrence. This case underscores the potential diagnostic limitations of routine preoperative assessment in atypical groin pathology and highlights the value of systematic posterior preperitoneal exploration during minimally invasive repair. Recognition of occult retroperitoneal extension is essential to prevent inadvertent neurovascular injury and ensure adequate mesh coverage. Reporting this rare bilateral presentation with psoas-related involvement expands the recognized anatomical spectrum of inguinal hernia disease and contributes to the limited body of literature on deep posterior variants.