Irreducible inguinal hernia containing a noncommunicating rudimentary uterine horn: A case report

Abstract

Müllerian duct anomalies presenting within an inguinal hernia are exceptionally rare in adult women. We report a case of an irreducible inguinal hernia containing a noncommunicating (type III) rudimentary uterine horn with the ipsilateral fallopian tube and discuss its diagnosis and management. A woman in her 40s (gravida2 para1) presented with a 20-year history of a painless, irreducible mass in her right inguinal region. Physical examination revealed a firm, fixed, nontender solid mass measuring approximately 3 × 4 cm, while pelvic examination was unremarkable. Ultrasonography indicated a unicornuate uterus with a contralateral solid mass, and pelvic magnetic resonance imaging subsequently identified a noncommunicating rudimentary uterine horn with the right fallopian tube herniating into the inguinal canal, which was confirmed during laparoscopic exploration. Laparoscopic transabdominal preperitoneal hernia repair was performed, involving excision of the herniated rudimentary horn and ipsilateral fallopian tube followed by a tension-free repair. The operative time was 95 min with an estimated blood loss of <50 mL, and the postoperative recovery course was uneventful. This case highlights that congenital Müllerian duct anomalies should be considered in the differential diagnosis of irreducible inguinal masses in adult women. Magnetic resonance imaging is the imaging modality of choice, and laparoscopic transabdominal preperitoneal repair enables simultaneous management of the hernia and associated anomalies, facilitating individualized intraoperative decisions regarding the round ligament.

Introduction

A unicornuate uterus with a rudimentary horn is a rare Müllerian duct anomaly. The noncommunicating, nonfunctional (type III) rudimentary horn is frequently asymptomatic and incidentally detected in adulthood. In exceedingly rare instances, the rudimentary horn and its ipsilateral adnexa may herniate through the inguinal canal, presenting as an irreducible mass—a diagnosis frequently overlooked in routine clinical practice. This report describes the case of a 40-year-old woman with an inguinal hernia containing a type III rudimentary uterine horn and the ipsilateral fallopian tube, highlighting this unusual presentation and its diagnostic and therapeutic considerations.

Case presentation

A woman in her 40s (gravida2 para1 (G2P1)) presented to the Affiliated Hospital of Youjiang Medical University for Nationalities in August 2025 with a right inguinal mass that had been present for >20 years; it had enlarged and become irreducible during the preceding year. She had initially noticed a soft, reducible mass measuring approximately 1 × 2 cm in size 2 decades ago. During the past year, it had increased in size to approximately 3 × 5 cm and become irreducible. Her menstrual cycle was regular (30–32 days) without dysmenorrhea, and the mass showed no cyclical variation. Her medical history included well-controlled hypertension. Obstetric history included one full-term vaginal delivery and one induced abortion. Her vital signs were stable. Physical examination revealed a firm, fixed, nontender, and irreducible mass, measuring approximately 3 × 4 cm, in the right inguinal region. Gynecological examination was unremarkable, with no left adnexal abnormalities. Pelvic ultrasonography demonstrated a right-sided unicornuate uterus and a solid, hypoechoic mass (approximately 3.5 × 3.8 cm) in the right inguinal region, appearing closely related to the uterus (Figure 1(a)). Pelvic magnetic resonance imaging (MRI) further delineated the anatomy, revealing a right-sided unicornuate uterus and a cord-like structure (approximately 4.0 × 3.2 cm), isointense to the myometrium, herniating through the right inguinal canal (Figure 1(b) to (i)). These findings were consistent with a right noncommunicating (type III) rudimentary uterine horn within an inguinal hernia. After obtaining informed consent, laparoscopic exploration was performed. The procedure comprised three principal steps. First, the rudimentary uterine horn was dissected and excised. The attached right round ligament was divided, followed by dissection of the ovarian ligament and vascular pedicle using an electrocautery hook (Figure 1(c) and (d)). Second, the specimen was retrieved intact in an endobag through a 10-mm trocar for pathological examination (Figure 1(g) and (h)). Finally, standard laparoscopic transabdominal preperitoneal (TAPP) hernia repair was performed (Figure 1(e)). A lightweight polypropylene mesh was placed in the preperitoneal space to cover the myopectineal orifice and secured using medical glue, followed by continuous peritoneal closure (Figure 1(f)). The total operative time was 95 min, with an estimated blood loss of <50 mL. The postoperative recovery course was uneventful.

Figure 1.

Diagnostic imaging, surgical procedure, and histopathological findings of an irreducible inguinal hernia containing a noncommunicating rudimentary uterine horn. (a) Pelvic and right inguinal ultrasound images (transabdominal and transvaginal): The arrow indicates a solid mass in the right inguinal region, with signal continuity to the uterine tissue. (b) Pelvic magnetic resonance imaging (MRI), T2-weighted Continued.fat-suppressed sequence: The hernial sac in the right inguinal canal (arrow) is continuous with the right rudimentary uterine horn. (c) Laparoscopic intraoperative view of the right inguinal region showing the hernial sac protruding through the right deep inguinal ring, consisting of the right rudimentary uterine horn and the ipsilateral fallopian tube. (d) Resected specimen of the right rudimentary uterine horn and fallopian tube, measuring approximately 3 × 2 cm, in a retrieval bag. (e) Laparoscopic TAPP view showing dissected hernial sac (arrow) freed from the inguinal canal, and key anatomical landmarks, including the inferior epigastric artery and pubic tubercle. (f) Laparoscopic TAPP view following mesh placement: A 10 × 15-cm lightweight polypropylene mesh is laid flat in the preperitoneal space, fully covering the myopectineal orifice. The mesh is fixed to the pubic tubercle, Cooper’s ligament, and anterior sheath of the rectus abdominis muscle. (g) Photomicrograph of the right fallopian tube (H&E stain, 20×) demonstrating normal mucosal architecture. (h) Photomicrograph of the right rudimentary uterine horn (H&E stain, 10×) showing bundles of smooth muscle without identifiable endometrial elements. (i) Pelvic magnetic resonance imaging (MRI), T2-weighted fat-suppressed sequence: Rudimentary uterine horn and unicornuate uterus. TAPP: transabdominal preperitoneal; H&E: hematoxylin and eosin.

Discussion

Inguinal hernias are significantly less common in women than in men (accounting for approximately 8%–16% of all cases) and exhibit distinct clinical characteristics. In up to 7% of women undergoing hernial repair, the hernial sac contains reproductive organs—such as the uterus, ovary, and fallopian tube—frequently in association with congenital Müllerian duct anomalies.^1–5 This association is further evidenced by reports of ovarian inguinal hernia in patients with Müllerian duct aplasia, renal dysplasia, and cervical somite anomalies (MURCS) syndrome. ⁶ Other rare hernial contents include normal ovaries, fallopian tubes, broad ligaments, and the appendix. ⁷ Therefore, inguinal hernia in females must be differentiated from hydrocele of the canal of Nuck, varicosities of the round ligament, cysts of the round ligament, disorders of sex development (such as complete androgen insensitivity syndrome/ovotesticular disorder of sex development (DSD)), and hernias containing abnormal contents (e.g. ovarian cysts and endometriosis-related lesions). The core diagnostic approaches include ultrasonography/computed tomography (CT), karyotype analysis, and laparoscopic exploration, which, when combined with clinical features (symptoms, age, and pregnancy status), can enable definitive differentiation.^8,9 The present case of an irreducible hernia containing a type III rudimentary uterine horn with the ipsilateral fallopian tube is rare. Its pathogenesis is attributed to abnormal Müllerian duct development and altered gonadal descent. Failed duct fusion may result in ectopic uterine positioning, with descent into the inguinal canal through a patent processus vaginalis.^10,11 In this patient, the absence of functional endometrium likely contributed to prolonged asymptomatic progression until enlargement and adhesions at the hernial sac neck led to irreducible incarceration, prompting intervention. Accurate preoperative imaging is pivotal for diagnosis and surgical planning. Although ultrasonography is useful for initial screening, it is operator-dependent. CT provides limited soft-tissue contrast for pelvic organs. Conversely, MRI, owing to its superior soft-tissue resolution and multiplanar capability, enables precise identification of myometrial tissue, classification of the rudimentary horn, and delineation of its relationship with adjacent structures, including the inferior epigastric vessels, providing decisive guidance for surgical management. ¹² The primary clinical challenge in this case was managing an irreducible hernia with rare gynecological structures. Laparoscopic TAPP repair represents an ideal approach as it provides a wide operative field for simultaneous exploration, management of anomalous structures, and tension-free hernia repair while preserving inguinal canal anatomy, thereby facilitating postoperative recovery.^13,14 Management of the round ligament remains controversial. ¹⁵ This debate centers on balancing repair durability against preservation of uterine support and potential reproductive function. Current consensus favors preservation in women of reproductive age, using techniques such as creating a mesh “keyhole.”^16–18 Conversely, several studies have reported no increase in the risk of hernia recurrence or chronic postoperative pain following division when repair integrity is maintained. ¹⁹ In the present case, division was required because the rudimentary horn originated directly from the right round ligament. Given the patient’s lack of fertility desire (G2P1) and the spontaneous retraction of the ligament stump, preservation was neither feasible nor indicated. This approach integrated anatomical requirements and patient-specific factors, underscoring the importance of individualized surgical decision-making. However, in female patients without such complex anomalies, surgeons should actively consider techniques to preserve the round ligament.

Conclusion

In adult women presenting with an irreducible inguinal mass, congenital Müllerian duct anomalies should be included in the differential diagnosis. MRI is the preferred modality for definitive evaluation. Laparoscopic TAPP repair allows concurrent management of the hernia defect and associated anomalous structures. Intraoperative management of the round ligament should be an individualized decision, considering the nature of the anomaly, reliability of hernia repair, and the patient’s reproductive intentions.