Situs inversus totalis with bilateral broad ligament defects identified during laparoscopic surgery: a case report

A 71-year-old Japanese woman (height, 160 cm; weight, 50 kg), gravida 2 para 2 (one vacuum-assisted vaginal delivery and one spontaneous vaginal delivery), who had undergone menopause at 50 years of age, was referred to our hospital. She had a known history of situs inversus totalis and had previously undergone surgery for acute appendicitis. Her medical history included hypertension, diabetes mellitus, and hypothyroidism, all of which were well-controlled with appropriate medical treatment. She had no significant family history and no history of smoking, alcohol consumption, drug allergies, or prior malignancy. The patient presented to a local clinic with a 6-month history of abnormal uterine bleeding. Endometrial cytology yielded suspicious findings, and endometrial biopsy demonstrated a few atypical glands. She was, therefore, referred to our gynecology department for further evaluation and management. At the initial visit to our institution, her vital signs were within normal limits. Transvaginal ultrasonography revealed a thickened endometrium measuring approximately 10 mm, along with a small amount of intrauterine fluid consistent with bleeding. Laboratory investigations showed mild liver dysfunction, with a total bilirubin level of 1.6 mg/dL, aspartate aminotransferase of 36 U/L, and alanine aminotransferase of 49 U/L. The D-dimer level was mildly elevated at 1.5 μg/mL; therefore, lower-extremity Doppler ultrasonography was performed as part of preoperative thromboembolism screening, which revealed no evidence of deep vein thrombosis. Serum tumor marker levels were also assessed as part of routine preoperative evaluation and were within normal ranges, including CA125 (10.0 U/mL), CA19-9 (2.0 U/mL), and carcinoembryonic antigen (2.1 ng/mL). Screening tests for hepatitis B virus, hepatitis C virus, syphilis, and human immunodeficiency virus were all negative. Contrast-enhanced pelvic MRI demonstrated an approximately 12-mm intrauterine mass with weak contrast enhancement (Fig.  1 ). The lesion showed high signal intensity on diffusion-weighted imaging (DWI) and low signal intensity on the ADC map, findings suggestive of malignancy. There was no evidence of myometrial invasion exceeding half of the myometrial thickness. No suspicious malignant lesions were identified in the cervix or adnexa. Contrast-enhanced CT confirmed complete situs inversus (Fig.  2 ), as previously known, and showed no findings suggestive of distant spread, including involvement of other organs or lymph nodes. Although differential diagnoses included endometrial hyperplasia, endometrial polyp, and submucosal leiomyoma, the overall imaging characteristics were highly suggestive of malignancy, and early-stage endometrial cancer was strongly suspected. Accordingly, laparoscopic total hysterectomy with bilateral salpingo-oophorectomy was planned. Histological confirmation using hysteroscopy is generally recommended prior to definitive surgical management; however, clinical decision-making must also consider the balance between diagnostic procedures and potential treatment delay. In the present case, abnormal uterine bleeding, imaging findings suggestive of malignancy, suspicious cytology, and atypical glandular proliferation on biopsy indicated a high likelihood of endometrial carcinoma. In our institution, hysteroscopic evaluation requires hospitalization and may delay definitive surgery by approximately 1–2 months due to scheduling constraints. After multidisciplinary discussion within the gynecologic team, it was considered that the potential risk of delaying treatment outweighed the benefit of additional diagnostic confirmation. The patient and her family were fully informed of the diagnostic uncertainty, the standard diagnostic approach, and the available management options, including hysteroscopic evaluation. Following shared decision-making, the patient expressed a preference for proceeding directly with surgical management. This approach is consistent with current clinical practice guidelines, including those of the Japan Society of Gynecologic Oncology and ESMO, which support treatment decision-making based on clinical and imaging findings in patients with a high suspicion of endometrial cancer [ 5 , 6 ]. Fig. 1 Contrast-enhanced pelvic MRI (T2-weighted sagittal image) shows an approximately 12-mm intrauterine mass with weak enhancement, findings suggestive of endometrial cancer. There is no evidence of myometrial invasion exceeding half of the myometrial thickness. No suspicious malignant lesions are identified in the cervix or adnexa Fig. 2 Contrast-enhanced CT images of the chest ( a ) and abdomen ( b ) demonstrate mirror-image positioning of the heart, liver, spleen, and stomach, consistent with situs inversus totalis. No evidence of distant metastasis or distant spread is observed Contrast-enhanced pelvic MRI (T2-weighted sagittal image) shows an approximately 12-mm intrauterine mass with weak enhancement, findings suggestive of endometrial cancer. There is no evidence of myometrial invasion exceeding half of the myometrial thickness. No suspicious malignant lesions are identified in the cervix or adnexa Contrast-enhanced CT images of the chest ( a ) and abdomen ( b ) demonstrate mirror-image positioning of the heart, liver, spleen, and stomach, consistent with situs inversus totalis. No evidence of distant metastasis or distant spread is observed On laparoscopic inspection of the abdominal cavity, no ascites or peritoneal dissemination was observed. Bilateral defects (fenestrations) measuring approximately 3–4 cm in diameter, as estimated by comparison with the length of the laparoscopic instrument tips, were identified in the broad ligament immediately beneath the round ligaments of the uterus (Fig.  3 ). No incarceration of the intestinal tract was noted. After careful confirmation of the anatomical relationships among the ureters, infundibulopelvic ligaments, and iliac vessels, laparoscopic total hysterectomy with bilateral salpingo-oophorectomy was performed as planned. The operative time was 141 min, and blood loss was minimal. The procedure was well-tolerated, with no intraoperative or postoperative complications; the patient was discharged on postoperative day 6, in accordance with our institutional postoperative management protocol. Histopathological examination revealed endometrial carcinoma (endometrioid carcinoma, grade 1), FIGO 2008 stage IA (Supplementary Fig. 1). No adjuvant therapy was administered. At 4 years of postoperative follow-up, the patient has remained free of recurrence. The patient was satisfied with the treatment and postoperative course and provided informed consent for publication of this case report. A timeline of the patient’s clinical course from initial presentation to postoperative follow-up is shown in Table  1 . Fig. 3 Laparoscopic views of the periphery of the uterus. On both the right ( a ) and left ( b ) sides, a peritoneal defect measuring approximately 3–4 cm in diameter is identified in the broad ligament immediately beneath the round ligament of the uterus. Through the fenestration, the peritoneum of the vesicouterine pouch is visible. No incarceration of intra-abdominal organs, including the small intestine, is observed Table 1 Timeline of the patient's clinical course Timepoint Clinical events  ~ 6 months before admission Onset of abnormal uterine bleeding Initial visit to local clinic Endometrial cytology suspicious; endometrial biopsy showed a few atypical glands Referral to our hospital Referred for further evaluation and management Initial evaluation at our hospital Vital signs stable; transvaginal ultrasonography showed thickened endometrium (~ 10 mm) Laboratory tests Mild liver dysfunction; D-dimer mildly elevated; tumor markers within normal limits Imaging studies Pelvic MRI revealed ~ 12-mm intrauterine mass with malignant features; CT confirmed situs inversus totalis without metastasis Preoperative diagnosis Suspected stage IA endometrial cancer (FIGO 2008) Surgery Laparoscopic total hysterectomy with bilateral salpingo-oophorectomy; bilateral peritoneal defects of the broad ligament identified Postoperative course Uneventful recovery; discharged on postoperative day 6 Histopathology Endometrioid carcinoma, grade 1, FIGO stage IA Follow-up (4 years) No evidence of recurrence Laparoscopic views of the periphery of the uterus. On both the right ( a ) and left ( b ) sides, a peritoneal defect measuring approximately 3–4 cm in diameter is identified in the broad ligament immediately beneath the round ligament of the uterus. Through the fenestration, the peritoneum of the vesicouterine pouch is visible. No incarceration of intra-abdominal organs, including the small intestine, is observed Timeline of the patient's clinical course

This report describes an uncommon case of situs inversus totalis in which bilateral peritoneal defects of the broad ligament were incidentally identified during laparoscopic surgery. The defects were discovered during laparoscopic total hysterectomy performed for suspected endometrial cancer. A peritoneal defect of the broad ligament of the uterus is a pathological condition characterized by partial absence of its peritoneal fold, which may be either congenital or acquired [ 1 ]. This condition is rare; in Japan, the prevalence of peritoneal defects (fenestrations) of the broad ligament has been estimated to be approximately 0.5% based on autopsy studies [ 2 ]. In contrast, situs inversus totalis is a congenital anomaly in which the thoracic and abdominal organs are arranged in a mirror-image configuration. Its prevalence in Japan has been reported to range from 0.25% to 0.53% [ 3 , 4 ]. By reviewing the relevant literature, we aimed to determine whether any association between these two conditions has been previously described and to discuss the clinical implications of this co-occurrence.

In this report, we describe an uncommon case of situs inversus totalis complicated by bilateral peritoneal defects of the broad ligament, which were incidentally identified during laparoscopic total hysterectomy with bilateral salpingo-oophorectomy. Situs inversus totalis is a rare congenital anomaly; its prevalence in Japan has been reported to range from approximately 0.25–0.53% [ 3 , 4 ], though estimates vary across studies and populations. Although the precise etiology of situs inversus totalis remains unclear, increasing evidence suggests that abnormalities in left–right axis determination during early embryogenesis play a central role. Genetic mutations affecting laterality-related ciliary genes, such as DNAH5 and ZIC3, have been reported to disrupt normal organ positioning [ 7 , 8 ]. The establishment of left–right asymmetry is primarily regulated by nodal ciliary function and molecular signaling pathways during early embryogenesis [ 9 , 10 ], and defects in ciliary motility have been shown to underlie conditions, such as primary ciliary dyskinesia and situs inversus [ 11 , 12 ]. The development of the broad ligament, by contrast, is related to the formation, fusion, and remodeling of the Müllerian ducts and surrounding peritoneal structures at a later developmental stage [ 13 ]. Consistent with the central role of ciliary dysfunction, situs inversus totalis is frequently associated with primary ciliary dyskinesia and Kartagener syndrome, conditions characterized by defective ciliary motility [ 11 , 12 ]. Thus, while ciliary dysfunction represents a key contributing mechanism, the full spectrum of etiological factors underlying situs inversus totalis has yet to be determined. Situs inversus totalis is known to be associated with congenital anomalies, particularly involving the cardiovascular system, as well as splenic, hepatic, and intestinal abnormalities [ 14 ]. In contrast, previous studies have suggested that situs inversus totalis is not associated with an increased incidence of malignant tumors [ 15 ]. We reviewed the literature to investigate whether any relationship between situs inversus totalis and peritoneal defects of the broad ligament has been reported. A literature search was conducted using PubMed and Google Scholar up to January 2026 with the keywords “situs inversus totalis,” “broad ligament,” “peritoneal defect,” and “internal hernia.” No previously published reports describing an association between these two conditions were identified. Accordingly, the coexistence observed in the present case is best interpreted as an extremely rare co-occurrence rather than evidence of a causal relationship. A peritoneal defect of the broad ligament represents a pathological condition characterized by a defect or fenestration in the peritoneal fold extending from the lateral margin of the uterus to the pelvic sidewall. Autopsy-based studies have estimated the prevalence of peritoneal defects of the broad ligament to be approximately 0.5%, and these defects may be either congenital or acquired [ 1 , 2 ]. Although a definitive conclusion regarding the etiology cannot be drawn, several acquired causes of peritoneal defects of the broad ligament have been reported, including prior pelvic or abdominal surgery, endometriosis, pregnancy- or delivery-related trauma, pelvic inflammatory disease, and inflammatory or ischemic injury to the peritoneum [ 1 , 16 – 19 ]. In the present case, the patient had a history of surgery for acute appendicitis; however, the defects were located bilaterally immediately beneath the uterine round ligaments, which are anatomically distant from the typical operative field of appendectomy. Moreover, the bilateral and symmetrical nature of the defects makes an acquired etiology due to localized surgical trauma less likely. The patient also had no history or clinical evidence of endometriosis, pelvic inflammatory disease, or other conditions known to cause acquired peritoneal defects. Therefore, while not conclusive, the absence of typical acquired risk factors, together with the anatomical distribution and embryological background, supports the possibility that the peritoneal defects were more likely congenital rather than acquired. However, the possibility of an unrecognized acquired origin cannot be completely excluded. According to the Hunt classification, peritoneal defects of the broad ligament are categorized into three types: fenestra type, pouch type, and hernia sac type [ 1 , 20 ]. To facilitate understanding of these classifications and the mechanism of broad ligament herniation, we created a schematic illustration based on previously reported cases (Fig.  4 ). The present case was classified as the fenestra type, as defects involving both peritoneal layers were identified. From a pathophysiological perspective, defects involving both peritoneal layers may create a potential channel through which small bowel loops can herniate under conditions of increased intra-abdominal pressure, thereby predisposing to internal herniation and possible strangulation, which represents the most clinically significant complication of this condition. Dowers et al. reported that the fenestra type is the most common, accounting for more than 80% of cases [ 18 , 19 ]. The broad ligament is formed through the development, fusion, and remodeling of the Müllerian ducts and surrounding peritoneal structures [ 13 ], and congenital defects may arise from incomplete fusion or focal weakness during this process. However, no specific genetic abnormalities or developmental pathways have been definitively linked to the formation of peritoneal defects of the broad ligament. Although no previous reports have described an association between defects of the broad ligament and generalized peritoneal fragility, the coexistence of localized peritoneal weakness at other intra-abdominal sites—such as those predisposing to obturator hernia, femoral hernia, or incisional abdominal wall hernia—cannot be excluded. Therefore, when peritoneal defects of the broad ligament are encountered, careful and comprehensive inspection of the entire peritoneal cavity is warranted to identify any additional areas of potential weakness. Fig. 4 Schematic illustration of broad ligament herniation according to the Hunt classification. The left side shows the fenestra type, characterized by defects involving both peritoneal layers, whereas the right side shows the pouch type, in which only a single peritoneal layer is deficient. This figure is an original illustration created by the authors to facilitate understanding of the fenestra and pouch types, inspired by a previously published case report of internal hernia through the broad ligament of the uterus [ 15 ] Schematic illustration of broad ligament herniation according to the Hunt classification. The left side shows the fenestra type, characterized by defects involving both peritoneal layers, whereas the right side shows the pouch type, in which only a single peritoneal layer is deficient. This figure is an original illustration created by the authors to facilitate understanding of the fenestra and pouch types, inspired by a previously published case report of internal hernia through the broad ligament of the uterus [ 15 ] From a clinical perspective, the most important complication associated with peritoneal defects of the broad ligament is the potential for internal herniation of adjacent organs, commonly referred to as broad ligament herniation. Although rare, the small intestine—particularly the ileum—is the most frequently herniated organ, and this condition may lead to small bowel obstruction or strangulated ileus [ 2 , 21 , 22 ]. The clinical manifestations of broad ligament herniation are often nonspecific, including abdominal pain, nausea, and vomiting, which makes preoperative diagnosis challenging [ 2 , 23 ]. Its rarity further contributes to diagnostic difficulty. Several characteristic imaging findings have been described, including (1) dilated small bowel loops in the pouch of Douglas or adjacent to the uterus, (2) deviation of the uterus caused by dilated bowel loops, and (3) congested mesentery surrounding the broad ligament on computed tomography [ 2 , 23 ]. When broad ligament herniation is diagnosed, surgical reduction of the incarcerated organ is required, followed by either closure or widening of the peritoneal defect. The choice of surgical approach depends largely on the size of the fenestration and intraoperative findings [ 2 , 23 ]. From a surgical perspective, several considerations are important when performing laparoscopic procedures in patients with situs inversus totalis. Previous reports on laparoscopic and minimally invasive surgery in patients with situs inversus totalis have consistently highlighted the technical challenges associated with mirror-image anatomical variation, including disorientation in spatial recognition, difficulty in instrument handling due to reversed laterality, and the need for modifications in port placement and surgeon positioning [ 24 – 28 ]. Recent studies have emphasized the importance of thorough preoperative imaging assessment, mental reorientation to mirror-image anatomy, and meticulous intraoperative identification of key structures, such as the ureters and major vessels to ensure surgical safety [ 24 – 28 ]. In some cases, adjustments in surgeon standing position or trocar configuration have been adopted to optimize ergonomics and visualization [ 24 – 28 ]. In the present case, a structured stepwise approach was employed to ensure safe completion of the procedure under mirror-image anatomical conditions. In the setting of total hysterectomy with bilateral salpingo-oophorectomy, the uterus serves as the central midline reference structure, and the adnexa and ureters are arranged symmetrically on either side. Accordingly, the overall sequence of surgical steps and the structures requiring division did not differ substantially from those in standard cases, and situs inversus totalis itself did not represent the principal technical challenge in this procedure. Rather, the more clinically relevant challenge arose from the bilateral broad ligament defects. In a standard case, the ureter is identified through retroperitoneal dissection along the posterior leaf of the broad ligament. In the present case, however, the partial absence of the broad ligament made the expected anatomical relationships of the ureters less straightforward, requiring greater caution during identification and dissection. Preoperatively, contrast-enhanced CT and MRI were carefully reviewed to confirm the mirror-image arrangement of the pelvic organs. However, the broad ligament defects were not identified preoperatively and were recognized only during laparoscopic inspection of the abdominal cavity. This unexpected intraoperative finding required real-time adaptation of the surgical strategy, with immediate heightened attention to ureteral identification and confirmation of adjacent structures before proceeding with each subsequent step. Intraoperatively, the ureters were identified at an early stage by carefully assessing their relationship to the infundibulopelvic ligaments and iliac vessels, and by confirming ureteral peristalsis through intact peritoneal structures adjacent to the defects, allowing early and reliable identification of their course. Given the presence of bilateral defects immediately beneath the round ligaments, the round ligaments, infundibulopelvic ligaments, and uterine vessels were all managed with particular caution, with deliberate confirmation of adjacent structures before division. Reflection of the uterovesical peritoneum was performed in the standard fashion, with continuous attention to the altered local anatomy. Thus, rather than requiring major modifications of standard laparoscopic technique, safe completion of the procedure depended on prompt intraoperative recognition of the broad ligament defects and a structured response consisting of early ureteral identification and meticulous stepwise confirmation of anatomical landmarks. Because broad ligament defects are often not identified on preoperative imaging and may first become apparent intraoperatively, awareness of their potential impact on pelvic anatomy may be more clinically relevant than mirror-image anatomy alone in selected cases. The present experience suggests that standard laparoscopic techniques can be safely applied even in the presence of such unexpected findings, provided that surgeons maintain a structured and adaptable approach to anatomical confirmation throughout the procedure. This report has several strengths, including detailed intraoperative documentation, clear radiologic–pathologic correlation, and long-term follow-up without recurrence. Nevertheless, as a single case report, it cannot establish causality or permit generalization. Genetic evaluation was not performed, and further accumulation of similar cases will be necessary to clarify whether the coexistence observed represents a coincidental finding or a yet-unrecognized developmental association. To our knowledge, this is the first reported case in which situs inversus totalis and bilateral peritoneal defects of the broad ligament were simultaneously identified during laparoscopic surgery. Although often asymptomatic, peritoneal defects of the broad ligament can cause internal herniation leading to strangulated ileus; therefore, awareness of this condition and careful interpretation of characteristic imaging findings are essential, particularly when evaluating patients presenting with acute abdomen, especially those without an apparent predisposing cause or prior abdominal surgery.

Additional file 1. Additional file 1.