Single-cell transcriptomic profiling of the neonatal oviduct and uterus reveals new insights into upper Müllerian duct regionalization.

The upper Müllerian duct (MD) is patterned and specified into two morphologically and functionally distinct organs, the oviduct and uterus. It is known that this regionalization process is instructed by inductive signals from the adjacent mesenchyme. However, the interaction landscape between epithelium and mesenchyme during upper MD development remains largely unknown. Here, we performed single-cell transcriptomic profiling of mouse neonatal oviducts and uteri at the initiation of MD epithelial differentiation (postnatal day 3). We identified major cell types including epithelium, mesenchyme, pericytes, mesothelium, endothelium, and immune cells in both organs with established markers. Moreover, we uncovered region-specific epithelial and mesenchymal subpopulations and then deduced region-specific ligand-receptor pairs mediating mesenchymal-epithelial interactions along the craniocaudal axis. Unexpectedly, we discovered a mesenchymal subpopulation marked by neurofilaments with specific localizations at the mesometrial pole of both the neonatal oviduct and uterus. Lastly, we analyzed and revealed organ-specific signature genes of pericytes and mesothelial cells. Taken together, our study enriches our knowledge of upper MD development, and provides a manageable list of potential genes, pathways, and region-specific cell subtypes for future functional studies.

Development and characterization of human fetal female reproductive tract organoids to understand Müllerian duct anomalies.

Müllerian ducts are paired tubular structures that give rise to most of the female reproductive organs. Any abnormalities in the development and differentiation of these ducts lead to anatomical defects in the female reproductive tract organs categorized as Müllerian duct anomalies. Due to the limited access to fetal tissues, little is understood of human reproductive tract development and the associated anomalies. Although organoids represent a powerful model to decipher human development and disease, such organoids from fetal reproductive organs are not available. Here, we developed organoids from human fetal fallopian tubes and uteri and compared them with their adult counterparts. Our results demonstrate that human fetal reproductive tract epithelia do not express some of the typical markers of adult reproductive tract epithelia. Furthermore, fetal organoids are grossly, histologically, and proteomically different from adult organoids. While external supplementation of WNT ligands or activators in culture medium is an absolute requirement for the adult reproductive tract organoids, fetal organoids are able to grow in WNT-deficient conditions. We also developed decellularized tissue scaffolds from adult human fallopian tubes and uteri. Transplantation of fetal organoids onto these scaffolds led to the regeneration of the adult fallopian tube and uterine epithelia. Importantly, suppression of Wnt signaling, which is altered in patients with Müllerian duct anomalies, inhibits the regenerative ability of human fetal organoids and causes severe anatomical defects in the mouse reproductive tract. Thus, our fetal organoids represent an important platform to study the underlying basis of human female reproductive tract development and diseases.

Direct diffusion of anti-Müllerian hormone from both the cranial and caudal regions of the testis during early gonadal development in mice.

BACKGROUND: The Müllerian duct (MD), the primordium of the female reproductive tract, is also formed in males during the early stage of development, then regresses due to the anti-Müllerian hormone (AMH) secreted from the testes. However, the detailed diffusion pathway of AMH remains unclear. We herein investigated the mechanism by which AMH reaches the middle region of the MD using an organ culture system. RESULTS: Injection of recombinant human AMH into the testis around the start of MD regression induced diffuse immunoreactivity in the mesonephros near the injection site. When the testis and mesonephros were cultured separately, the diameters of both cranial and middle MDs were significantly increased compared to the control. In the testis-mesonephros complex cultured by inhibiting the diffusion of AMH through the cranial region, the cranial MD diameter was significantly increased compared to the control, and there was no difference in middle MD diameter. CONCLUSIONS: These results indicate that AMH, which infiltrates from the testis through the cranial region at physiological concentrations, induces regression of the cranial MD at the start of MD regression. They also indicate that AMH infiltrating through the caudal regions induces regression of the middle MD.

Perturbations of genes essential for Müllerian duct and Wölffian duct development in Mayer-Rokitansky-Küster-Hauser syndrome.

Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) is associated with congenital absence of the uterus, cervix, and the upper part of the vagina; it is a sex-limited trait. Disrupted development of the Müllerian ducts (MD)/Wölffian ducts (WD) through multifactorial mechanisms has been proposed to underlie MRKHS. In this study, exome sequencing (ES) was performed on a Chinese discovery cohort (442 affected subjects and 941 female control subjects) and a replication MRKHS cohort (150 affected subjects of mixed ethnicity from North America, South America, and Europe). Phenotypic follow-up of the female reproductive system was performed on an additional cohort of PAX8-associated congenital hypothyroidism (CH) (n = 5, Chinese). By analyzing 19 candidate genes essential for MD/WD development, we identified 12 likely gene-disrupting (LGD) variants in 7 genes: PAX8 (n = 4), BMP4 (n = 2), BMP7 (n = 2), TBX6 (n = 1), HOXA10 (n = 1), EMX2 (n = 1), and WNT9B (n = 1), while LGD variants in these genes were not detected in control samples (p = 1.27E-06). Interestingly, a sex-limited penetrance with paternal inheritance was observed in multiple families. One additional PAX8 LGD variant from the replication cohort and two missense variants from both cohorts were revealed to cause loss-of-function of the protein. From the PAX8-associated CH cohort, we identified one individual presenting a syndromic condition characterized by CH and MRKHS (CH-MRKHS). Our study demonstrates the comprehensive utilization of knowledge from developmental biology toward elucidating genetic perturbations, i.e., rare pathogenic alleles involving the same loci, contributing to human birth defects.

Lack of causative mutation in the AMH and AMHR2 genes in a cat (38,XY) with persistent Mullerian duct syndrome (PMDS).

A 1-year-old European shorthair male cat with a normally developed penis was subjected to genetic, endocrinological and histological studies due to unilateral cryptorchidism. The blood testosterone level was typical for males, while the level of anti-Mullerian hormone (AMH) was very low. Surgical removal of internal reproductive organs was followed by a histological study, which revealed inactive testicles with neoplastic changes and derivatives of Mullerian ducts. Cytogenetic analysis showed a normal XY sex chromosome complement and molecular analysis confirmed the presence of Y-linked genes (SRY and ZFY). Although the level of AMH was low, two normal copies of the AMH gene were found using droplet digital PCR (ddPCR). Analysis of the coding sequences of two candidate genes (AMH and AMHR2) for persistent Mullerian duct syndrome (PMDS) in the affected cat and in control male cats (n = 24) was performed using the Sanger sequencing method. In the affected cat, homozygosity was found for three novel missense variants in Exon 1 (one SNP) and Exon 5 (two SNPs) of AMH, but the same homozygous genotypes were also observed in one and two control cats, respectively, whose sex development was not examined. Three known synonymous variants with homozygous status were found in AMHR2. We conclude that the DNA variants identified in AMH and AMHR2 are not responsible for PMDS in the affected cat.

Wnt4a Is Indispensable for Genital Duct Elongation but Not for Gonadal Sex Differentiation in the Medaka, Oryzias latipes.

In most vertebrates, the oviducts and sperm ducts are derived from the Müllerian ducts and Wolffian ducts, respectively. However, in teleosts, the genital ducts are formed by the posterior extension of gonads in both sexes. Whether the genital ducts of teleosts are newly evolved organs or variants of Müllerian ducts is an important question for understanding evolutionary mechanisms of morphogenesis. One of the genes essential for Müllerian duct formation in mice is Wnt4, which is expressed in the mesenchyme and induces invagination of the coelomic epithelium and its posterior elongation. Here, we addressed the above question by examining genital duct development in mutants of two Wnt4 genes in the medaka (wnt4a is orthologous to mouse Wnt4, and wnt4b is paralogous). The wnt4b mutants had a short body but were fertile with normal genital ducts. In contrast, both male and female wnt4a mutants had their posterior elongation of the gonads stopped within or just outside the coelom. The mutants retained the posterior parts of ovarian cavities or sperm duct primordia, which are potential target tissues of Wnt4a. The gonads of female scl mutants (unable to synthesize sex steroids) lacked these tissues and did not develop genital ducts. Medaka wnt4a was expressed in the mesenchyme ventral to the genital ducts in both sexes. Taken together, the data strongly suggest that the mouse Müllerian ducts and the medaka genital ducts share homologous developmental processes. Additionally, the wnt4a or wnt4b single mutants and the double mutants did not show sex-reversal, implying that both genes are dispensable for gonadal sex differentiation in the medaka.

A Common Path: Magnetic Resonance Imaging of Müllerian and Wolffian Duct Anomalies.

PURPOSE OF REVIEW: This review summarizes the pathway of Mullerian and Wolffian duct development, anomalies that result from disruptions to this pathway, and the characteristics on advanced imaging that identify them. RECENT FINDINGS: In-office evaluation for reproductive anomalies is usually inadequate for the diagnosis of congenital reproductive anomalies. Magnetic resonance imaging (MRI) has usurped invasive diagnostic methods including laparoscopy, hysteroscopy, and vasography as the new gold standard. Because of its superior soft-tissue delineation and the availability of advanced functional sequences, MRI offers a sophisticated method of distinguishing reproductive anomalies from one another, characterizing the degree of defect severity, and evaluating for concomitant urogenital anomalies non-invasively and without radiation exposure to the patient. Congenital anomalies of the Mullerian and Wolffian duct can be incredibly nuanced, requiring prompt and accurate diagnosis for management of infertility. Definitive diagnosis should be made early with MRI.

Aggressive Cervical Dilation Exploits Potential Weakness in the Septum of Duplicated Cervix during Hysteroscopic Cervix-preserving Metroplasty of Complete Septate Uterus: A Cohort Study.

STUDY OBJECTIVE: To evaluate whether aggressive cervical dilation is effective for creating the initial perforation between noncommunicating cavities of the complete septate uterus (CSU), which serves as the first step of hysteroscopic cervix-preserving metroplasty (CPM). DESIGN: A retrospective cohort. SETTING: A tertiary referral center. PATIENTS: Fifty-three patients with CSU were diagnosed using vaginal examinations, combined two- and three-dimensional vaginal ultrasounds, and office-based hysteroscopies. INTERVENTIONS: Patients who had received hysteroscopic CPM with the initial perforation created by aggressive cervical dilation or by the traditional method of bougie-guided incisions were compared. MEASUREMENTS AND MAIN RESULTS: Of the 53 patients with CSU, 44 patients received hysteroscopic CPM that required the creation of a perforation. Patients who received aggressive cervical dilation for creation of the perforation had nonsignificantly shorter surgical times (33.5 minutes, 95% confidence interval [CI], 28.4-38.6 vs 48.7 minutes, 95% CI, 28.2-71.3, p = .099), used significantly lower volumes of distending media (3.6 liters, 95% CI, 3.1-4.1 vs 6.8 liters, 95% CI, 4.2-9.3, p <.001), and had higher success rates (84.4%, 95% CI, 67.2-94.7 vs 50.0%, 95% CI, 21.1-78.9, p = .019). The sites of perforation all occurred on the endocervical septum and were generally fibrous and avascular. CONCLUSION: We present a novel, effective method for creating the initial perforation in hysteroscopic CPM. The success may be because of the existence of a potential weakness in the septum of the duplicated cervix, which spontaneously tears upon aggressive mechanical dilation. The method forgoes the risks associated with sharp incisions based on potentially unreliable cues and may greatly simplify the procedure.

Ex vivo development of the entire mouse fetal reproductive tract by using microdissection and membrane-based organ culture techniques.

Ex vivo explant culture is an appealing alternative to in vivo studies on fetal reproductive organ development. There is extensive literature on ex vivo methods of growing the fetal gonad. However, a method for culturing the whole fetal reproductive tract that has a different shape and size has not been documented. Here, with careful dissection and proper tissue orientation, we successfully cultured the entire bicornuate reproductive tracts from mouse embryos of both sexes on the Transwell insert membrane. The cultured reproductive tract system undergoes sexually dimorphic establishment and region-specific morphogenesis comparable to in vivo development of their counterparts. To test this culture method's applications, we used chemical treatment (dihydrotestosterone and BMS 564929) and genetic cellular ablation mouse model (Gli1-CreER; Rosa-DTA) to investigate the roles of androgen signaling and Gli1+ mesenchyme in Wolffian duct development. Dihydrotestosterone and BMS 564929 promoted the ectopic maintenance of Wolffian ducts in cultured XX tissues. The efficient and specific elimination of Gli1+ mesenchyme was successfully achieved in the cultured tissues, resulting in defective coiling of Wolffian ducts. These results demonstrate the amenability of this organ culture method for chemical and genetic manipulations that are otherwise difficult to study in vivo. Taken together, the establishment of this organ culture method provides a valuable tool complementary to in vivo studies for understanding fetal reproductive tract development in mice.

Persistent Müllerian Duct Syndrome Diagnosed Incidentally: A Case Report.

Persistent Müllerian Duct syndrome is a rare male disorder of sexual development. The phenotypically and genotypically male patient presents with female internal organs (i.e., uterus, cervix, fallopian tubes and upper part of vagina) due to deficiency of anti-mullerian hormone or insensitivity of tissues to Anti Mullerian Hormone. We present a 19 year old male who came with complaint of right iliac fossa pain. He was investigated for acute appendicitis and on imaging, he was diagnosed to have bilateral cryptorchidism with rudimentary uterus. Computed tomography followed by pelvic ultrasonography was done which indicated two testes in abdomen and a soft tissue density structure, identified as a rudimentary uterus located posterior to the urinary bladder. CT scan findings were further confirmed by magnetic resonance imaging pelvis. A trial of stepwise orchidopexy followed by orchidectomy with removal of rudimentary uterus was performed laparoscopically. Additionally, he was counselled for long term sex hormone replacement and reproductive failure in future.

Persistent Müllerian duct syndrome: A surgical surprise and management during laparoscopic transabdominal pre-peritoneal repair.

Persistent Müllerian duct syndrome is an intersex disorder which occurs due to the failure of regression of Müllerian structures in genotypical and phenotypical males. It is a rare disorder of male internal pseudohermaphroditism with normal secondary sexual characters and XY karyotype. We report a male patient with the diagnosis of bilateral inguinoscrotal hernia with cryptorchidism scheduled for laparoscopic bilateral transabdominal pre-peritoneal (TAPP) mesh repair with bilateral orchidopexy. Intra-operatively, there was a rudimentary uterus with tubes on both sides. Bilateral testicular biopsy was taken to confirm the presence of testicular tissue and to exclude malignancy and ovarian tissue. Hernia surgery was deferred in the first stage. After 2 weeks, he underwent laparoscopic bilateral orchidopexy with TAPP mesh repair. At 6-year follow-up, there is no recurrence of hernia or features of malignancy in the retained testis.

Lats1 and Lats2 are required for the maintenance of multipotency in the Müllerian duct mesenchyme.

WNT signaling plays essential roles in the development and function of the female reproductive tract. Although crosstalk with the Hippo pathway is a key regulator of WNT signaling, whether Hippo itself plays a role in female reproductive biology remains largely unknown. Here, we show that conditional deletion of the key Hippo kinases Lats1 and Lats2 in mouse Müllerian duct mesenchyme cells caused them to adopt the myofibroblast cell fate, resulting in profound reproductive tract developmental defects and sterility. Myofibroblast differentiation was attributed to increased YAP and TAZ expression (but not to altered WNT signaling), leading to the direct transcriptional upregulation of Ctgf and the activation of the myofibroblast genetic program. Müllerian duct mesenchyme cells also became myofibroblasts in male mutant embryos, which impeded the development of the male reproductive tract and resulted in cryptorchidism. The inactivation of Lats1/2 in differentiated uterine stromal cells in vitro did not compromise their ability to decidualize, suggesting that Hippo is dispensable during implantation. We conclude that Hippo signaling is required to suppress the myofibroblast genetic program and maintain multipotency in Müllerian mesenchyme cells.

Morphogenesis of the female reproductive tract along antero-posterior and dorso-ventral axes is dependent on Amhr2+ mesenchyme in mice†.

Morphogenesis of the female reproductive tract is regulated by the mesenchyme. However, the identity of the mesenchymal lineage that directs the morphogenesis of the female reproductive tract has not been determined. Using in vivo genetic cell ablation, we identified Amhr2+ mesenchyme as an essential mesenchymal population in patterning the female reproductive tract. After partial ablation of Amhr2+ mesenchymal cells, the oviduct failed to develop its characteristic coiling due to decreased epithelial proliferation and tubule elongation during development. The uterus displayed a reduction in size and showed decreased cellular proliferation in both epithelial and mesenchymal compartments. More importantly, in the uterus, partial ablation of Amhr2+ mesenchyme caused abnormal lumen shape and altered the direction of its long axis from the dorsal-ventral axis to the left-right axis (i.e., perpendicular to the dorsal-ventral axis). Despite these morphological defects, epithelia underwent normal differentiation into secretory and ciliated cells in the oviduct and glandular epithelial cells in the uterus. These results demonstrated that Amhr2+ mesenchyme can direct female reproductive tract morphogenesis by regulating epithelial proliferation and lumen shape without affecting the differentiation of epithelial cell types.

An evo-devo perspective of the female reproductive tract.

The vertebrate female reproductive tract has undergone considerable diversification over evolution, having become physiologically adapted to different reproductive strategies. This review considers the female reproductive tract from the perspective of evolutionary developmental biology (evo-devo). Very little is known about how the evolution of this organ system has been driven at the molecular level. In most vertebrates, the female reproductive tract develops from paired embryonic tubes, the Müllerian ducts. We propose that formation of the Müllerian duct is a conserved process that has involved co-option of genes and molecular pathways involved in tubulogenesis in the adjacent mesonephric kidney and Wolffian duct. Downstream of this conservation, genetic regulatory divergence has occurred, generating diversity in duct structure. Plasticity of the Hox gene code and wnt signaling, in particular, may underlie morphological variation of the uterus in mammals, and evolution of the vagina. This developmental plasticity in Hox and Wnt activity may also apply to other vertebrates, generating the morphological diversity of female reproductive tracts evident today.

Persistent Müllerian duct syndrome associated with genetic defects in the regulatory subunit of myosin phosphatase.

STUDY QUESTION: Can mutations of genes other than AMH or AMHR2, namely PPP1R12A coding myosin phosphatase, lead to persistent Müllerian duct syndrome (PMDS)? SUMMARY ANSWER: The detection of PPP1R12A truncation mutations in five cases of PMDS suggests that myosin phosphatase is involved in Müllerian regression, independently of the anti-Müllerian hormone (AMH) signaling cascade. WHAT IS KNOWN ALREADY: Mutations of AMH and AMHR2 are detectable in an overwhelming majority of PMDS patients but in 10% of cases, both genes are apparently normal, suggesting that other genes may be involved. STUDY DESIGN, SIZE, DURATION: DNA samples from 39 PMDS patients collected from 1990 to present, in which Sanger sequencing had failed to detect biallelic AMH or AMHR2 mutations, were screened by massive parallel sequencing. PARTICIPANTS/MATERIALS, SETTING, METHODS: To rule out the possibility that AMH or AMHR2 mutations could have been missed, all DNA samples of good quality were analyzed by targeted next-generation sequencing. Twenty-four samples in which the absence of AMH or AMHR2 biallelic mutations was confirmed were subjected to whole-exome sequencing with the aim of detecting variants of other genes potentially involved in PMDS. MAIN RESULTS AND THE ROLE OF CHANCE: Five patients out of 24 (21%) harbored deleterious truncation mutations of PP1R12A, the gene coding for the regulatory subunit of myosin phosphatase, were detected. In addition to PMDS, three of these patients presented with ileal and one with esophageal atresia. The congenital abnormalities associated with PMDS in our patients are consistent with those described in the literature for PPP1R12A variants and have never been described in cases of AMH or AMHR2 mutations. The role of chance is therefore extremely unlikely. LIMITATIONS, REASONS FOR CAUTION: The main limitation of the study is the lack of experimental validation of the role of PPP1R12A in Müllerian regression. Only circumstantial evidence is available, myosin phosphatase is required for cell mobility, which plays a major role in Müllerian regression. Alternatively, PPP1R12A mutations could affect the AMH transduction pathway. WIDER IMPLICATIONS OF THE FINDINGS: The study supports the conclusion that failure of Müllerian regression in males is not necessarily associated with a defect in AMH signaling. Extending the scope of molecular analysis should shed light upon the mechanism of the initial steps of male sex differentiation. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by la Fondation Maladies Rares, GenOmics 2021_0404 and la Fondation pour la Recherche Médicale, grant EQU201903007868. The authors report no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Adolescent abdominal pain due to rare mullerian duct anomaly.

Abdominal pain is a common presenting complaint to the Emergency Department (ED). Often, rare etiologies can be discovered in the work up of this common complaint. Here we present the case of an adolescent female who presented with abdominal pain and was found to have obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) or Herlyn-Werner-Wunderlich Syndrome. A 12 year old female with known renal agenesis presented with 5 days of left sided abdominal pain that then developed into right lower quadrant pain. She had regular menses for the last 2 years. Ultrasound (US) showed a fluid collection in the lower uterine segment and a complex cystic structure anterior to the uterus. Magnetic resonance imaging (MRI) showed the patient to have didelphys uterus with "severe dilatation of the cervix/vaginal canal… extending from the right uterine horn" and left-sided ovarian and Fallopian tube torsion. She was taken to the operating room where she underwent vaginal septum excision and a left salpingo-oopherectomy. OHVIRA includes the triad of obstructed hemivagina, uterine didelphys, and ipsilateral renal agenesis. This occurs due to embryologic arrest of the mullerian and mesonephric ducts at 8 weeks of gestation. Most abnormalities are right sided which leads to right lower abdominal and pelvic pain approximately 4 months post-menarche. Diagnosis of OHVIRA is made utilizing US and CT scans. MRI can also be useful to further delineate specific anatomy. It is important for the emergency physician to be aware of this entity as most patients don't present to care until acute, severe symptoms develop. This makes it more likely for them to seek care in the ED as opposed to the outpatient setting.

Imaging of congenital genitourinary anomalies.

Congenital genitourinary anomalies are among the most frequent types of birth defects in neonates. Some anomalies can be a significant cause of morbidity in infancy, while others remain asymptomatic even until adulthood and can be at times the only manifestation of a complex systemic disease. The spectrum of these anomalies results from the developmental insults that can occur at various embryologic stages, and an understanding of the formation of the genitourinary system is helpful in the evaluation and treatment of a child with a congenital genitourinary anomaly. Imaging plays an essential role in the diagnosis of congenital genitourinary anomalies and treatment planning. In this article, we highlight the embryologic and characteristic imaging features of various congenital genitourinary anomalies, demonstrate the utility of different imaging modalities in management, and review specific imaging modalities and protocols for image optimization.

New frontiers of developmental endocrinology opened by researchers connecting irreversible effects of sex hormones on developing organs.

In the early 1960's, at Professor Bern's laboratory, University of California, Berkeley) in the US, Takasugi discovered ovary-independent, persistent vaginal changes in mice exposed neonatally to estrogen, which resulted in vaginal cancer later in life. Reproductive abnormalities in rodents were reported as a result of perinatal exposure to various estrogenic chemicals. Ten years later, vaginal cancers were reported in young women exposed in utero to the synthetic estrogen diethylstilbestrol (DES) and this has been called the "DES syndrome". The developing organism is particularly sensitive to developmental exposure to estrogens inducing long-term changes in various organs including the reproductive organs. The molecular mechanism underlying the persistent vaginal changes induced by perinatal estrogen exposure was partly demonstrated. Persistent phosphorylation and sustained expression of EGF-like growth factors, lead to estrogen receptor α (ESR1) activation, and then persistent vaginal epithelial cell proliferation. Agents which are weakly estrogenic by postnatal criteria may have major developmental effects, especially during a critical perinatal period. The present review outlines various studies conducted by four generations of investigators all under the influence of Prof. Bern. The studies include reports of persistent changes induced by neonatal androgen exposure, analyses of estrogen responsive genes, factors determining epithelial differentiation in the Müllerian duct, ESR and growth factor signaling, and polyovular follicles in mammals. This review is then expanded to the studies on the effects of environmental estrogens on wildlife and endocrine disruption in Daphnids.

A rare variant of obstructed hemivagina and ipsilateral renal agenesis and its improvement of classification.

Obstructed hemivagina and ipsilateral renal agenesis (OHVIRA) is a rare congenital malformation of the female reproductive organs, including uterine dysplasia, blind hemivagina, and ipsilateral renal dysplasia. It has a serious impact on patients' quality of life and fertility. We report a rare case of OHVIRA with a complete septate uterus, ectopic dysplasia of the left kidney, left ectopic ureter, and three oblique vaginal septa. The dysplastic left kidney and the ectopic ureter were removed during laparoscopy. In addition, the two layers of vaginal septa, which were ignored in the past 10 years, were removed by hysteroscopy. As the detection rate of OHVIRA has gradually increased, manifestations that previous classification systems could not recapitulate have emerged. By retrieving the relevant cases, we have tried to propose a new classification system, which would allow clinicians to have a complete understanding of the manifestations of OHVIRA and would be helpful in the treatment of patients.

Transverse testicular ectopia with persistent Mullerian duct syndrome: Report and review of two cases.

Transverse testicular ectopia is a rare anomaly characterized by both testes descending through a single inguinal canal. The objective of this study was to investigate the pathogenesis, diagnosis, and treatment of transverse testicular ectopia (TTE) with persistent Mullerian duct syndrome (PMDS), and to deepen the understanding of the disease in clinical. A retrospective analysis of the clinical manifestation, diagnosis, and treatment of two children suffering from TTE with PMDS was conducted. Previous studies on the characteristics, diagnosis, and treatment of this disease were reviewed. The two patients were treated with laparoscopy-assisted transseptal orchidopexy-inguinal evaluation. After the surgery, the two patients recovered well. The follow-up visits were done 3 months after the operation. An ultrasound examination confirmed that the two patients had testes in the orthotopic position and normal size. TTE with PMDS is an exceedingly rare disease. The patients manifested cryptorchidism on one side; contralateral inguinal hernia was suspected. Detailed physical and ultrasound examinations before the operation are the key to the early diagnosis of TTE. Laparoscopic evaluation is helpful for the diagnosis and finding of other abnormalities. Surgical treatment is the only method to cure the disease; long-term follow-up is needed after TTE operation.