Cystic dysplasia of the epididymis: a disorder of mesonephric differentiation associated with renal maldevelopment.

The occurrence of congenital epididymal malformations with a cystic component has not been fully characterized. Most epididymal cysts occur later in life and are likely acquired. In addition, congenital malformations of the male excretory system are extremely uncommon in fetuses and neonates, and epididymal dysplastic changes have not been reported in these cases. In this study, we report 20 cases (including 19 fetal/neonatal autopsies and one surgical specimen from an older child) showing the same spectrum of histological findings in the epididymis, characterized by cystic ductal dilation with dysplastic ducts of variable diameters and irregular shapes, with ill-defined walls. Efferent ductules also showed dysplastic features. In addition, 18 cases had either renal and/or urinary tract anomalies, including renal dysplasia (eight), pelvicaliceal dilation (eight), renal agenesis (four) and hypoplasia (one), ureteral agenesis (two) and hypoplasia (one), urethra and bladder agenesis (two), prostate agenesis (two), and autosomal recessive polycystic renal disease (two). Our observations led to the recognition of a peculiar, not previously described congenital lesion of the epididymis, and we propose the term cystic dysplasia of the epididymis for this anomaly. Similar to what is observed in other male genital system anomalies (including malformations of the rete testis, vas deferens, and seminal vesicles), most lesions occurred in association with renal and/or urinary tract malformations, suggesting a spectrum of congenital malformations. The shared embryological origin of these structures may explain their simultaneous occurrence, possibly related to disrupted mesonephric duct development.

Six1 and Six4 are essential for Gdnf expression in the metanephric mesenchyme and ureteric bud formation, while Six1 deficiency alone causes mesonephric-tubule defects.

Interaction between the ureteric-bud epithelium and the metanephric mesenchyme is important for kidney development. Six1 and Six4 are the mammalian homologs of Drosophila sine oculis, and they are coexpressed in the nephrogenic mesenchyme. Six1-deficient mice show varying kidney defects, while Six4-deficient mice have no apparent abnormalities. Here, we report Six1/Six4-deficient mice that we generated in order to elucidate the functions of Six4 in Six1-deficient kidney development. The Six1/Six4-deficient mice exhibited more severe kidney phenotypes than the Six1-deficient mice; kidney and ureter agenesis was observed in all the neonates examined. The Six1/Six4-deficient metanephric mesenchyme cells were directed toward kidney lineage but failed to express Pax2, Pax8, or Gdnf, whereas the expression of these genes was partially reduced or unchanged in the case of Six1 deficiency. Thus, Six4 cooperates with Six1 in the metanephric mesenchyme to regulate the level of Gdnf expression; this could explain the absence of the ureteric bud in the Six1/Six4-deficient mice. In contrast, Six1 deficiency alone caused defects in mesonephric-tubule formation, and these defects were not exacerbated in the Six1/Six4-deficient mesonephros. These results highlight the fact that Six1 and Six4 have collaborative functions in the metanephros but not in the mesonephros.

Septate uterus with double cervices, unilaterally obstructed vaginal septum, and ipsilateral renal agenesis: a rare combination of müllerian and wolffian anomalies complicated by severe endometriosis in an adolescent.

We present a previously unreported combination of müllerian and wolffian anomalies of a septate uterus with double cervices, unilaterally obstructed vaginal septum, and ipsilateral renal agenesis; this constellation of findings may offer clues that could modify classic embryologic explanations. In spite of the young age of our patient (15-years old), a chief complaint of malodorous vaginal discharge, and absence of dysmenorrhea or any other symptoms of endometriosis, laparoscopic examination revealed severe endometriosis with dense adhesions, probably as a result of abundant menstrual regurgitation. Laparoscopic resection of endometriotic lesions, adhesiolysis, and vaginoscopic septotomy were successfully performed while preserving hymenal integrity.

The quail mesonephros: a new model for renal senescence?

BACKGROUND/AIMS: Renal senescence during normal aging is associated with specific vascular alterations and tissue degeneration. Although the degenerative program executed during embryonic kidney development is known to include vascular alterations, studies yet have to examine whether it involves replicative senescence. In this study, we assessed the potential of the quail mesonephros, a transitory embryonic kidney, as a model of human renal senescence. METHODS: Quail embryos with developing or degenerating mesonephros were studied on day 6 or day 11 of incubation, respectively. Senescence-associated beta-galactosidase activity, a marker of replicative senescence, was examined on whole mounts and sections. Senescent vascular characterization was performed by the scanning electron-microscopic analysis of vascular corrosion casts. RESULTS: Senescence-associated beta-galactosidase activity was found only in old mesonephros. Moreover, at 11 days of incubation glomerular capillaries showed discontinuities and were thinner and more tortuous than those observed at 6 days, characteristics also reported for the aging human kidney. CONCLUSION: The degenerating quail mesonephros is a potential model of renal senescence, showing biochemical and morphological characteristics of the aging human kidney.

[Congenital absence of the vas deferens].

Congenital absence of the vas deferens (CAVD) is an important factor that contributes to obstructive azoospermia and male infertility. The etiology of CAVD is associated with the cystic fibrosis transmembrane conductance regulator (CFTR) gene and defects in the Wolffian duct, and frequently complicated by renal agenesis and other urogenital abnormalities. Physical examination may reveal nonpalpable scrotal vas deferentia, while vasography intrinsic vasal absence. Ultrasound and computerized tomography (CT) can rule out the abnormalities of the upper urinary tracts and the seminal vesicles. Although it is difficult to cure the disease, it is now possible for CAVD patients to father children with the help of assisted reproductive technology (ART). The present review is focused on the etiology, diagnosis and treatment of CAVD.

Uncommon ureteric ectopias: embryological implications.

We herein report two rare ureteric ectopias, one in the uterus, the second in the rectum. These kinds of ectopias are not easily explained with regard to the classic embryological theories of the too-cranial or too-caudal origin of the ureteric bud on the mesonephric duct. We thus set out new explanations consistent with embryological studies on the narrow contact between the developing paramesonephric and mesonephric ducts, and on the so-called cloacal septation.

Apparent mesonephric duct (rete anlage) origin for cysts and proliferative epithelial lesions in the mouse ovary.

Ovaries and adjacent parovarian (mesovarial) tissues of CD-1 mice of various ages were examined to characterize cystic and proliferative epithelial lesions of the ovary and parovarian tissues. Ovaries and adjacent tissues from 6 mice each at approximately 3 and 8 months of age were processed for light microscopy and step-sections (50-micron intervals) of the entire tissue were examined. Tissues were collected from 40 mice each at 16 through 24 months of age and 3 step sections per mouse were examined. Mesonephric duct remnants were found in all mice at 3 and 8 months. Ducts were usually in the mesovarial adipose tissue and near or within the ovarian hilus and were often loosely associated with smooth muscle of the mesovarial ligament. The epithelium of the ducts varied from low cuboidal to columnar, occasional individual cells were ciliated, and small papillary configurations of epithelium were occasionally present. Ducts were dilated (> 1 mm) more often in mice at 8 months compared to 3 months, and some were continuous with cystic spaces within the ovaries. As mice aged (16-24 months), dilation and cystic change in ducts and associated compression of ovarian tissue away from the ovarian hilus became common. The epithelium of dilated ducts was generally flattened, but foci of cuboidal to columnar epithelium and/or occasional ciliated cells were present. Many ducts contained foci of hyperplastic and/or hypertrophic epithelium, and papillary projections of epithelium were occasionally found. Some of the latter lesions were consistent with a diagnosis of papillary cystadenoma. Hyperplasia of associated fibromuscular stroma was limited to a few apparently extraovarian ducts. The results of this study indicate that remnant mesonephric ductular structures are common in and adjacent to the ovaries of CD-1 mice. As mice age, these ducts become dilated and, in some, the epithelium becomes hyperplastic and/or hyperptrophic. These mesonephric duct remnants appear to be a common source of ovarian and parovarian cyts cysts and epithelial neoplasms of the ovary in mice.

Primary vaginal adenocarcinoma arising from the metanephric duct remnant.

Primary vaginal adenocarcinoma unrelated to in utero exposure to diethylstilbestrol (DES) is very uncommon. We report a case of 65-year-old Japanese woman who presented with primary adenocarcinoma in the anterior wall of the vagina, where the left ureter-like metanephric duct remnant abnormally terminated. Histological examination in serial sections revealed the direct connection between the carcinoma and the metanephric duct remnant. Moreover, the remnant epithelium showed varying degrees of dysplastic changes, including carcinoma in situ in close proximity to the carcinoma. This patient also had a bicornate uterus and left renal aplasia. To our knowledge, this is the first reported case of a primary vaginal adenocarcinoma arising from the metanephric duct remnant. Although the precise mechanism involved in carcinogenesis in this clinicopathological setting remains unknown, adenocarcinoma should be included in the differential diagnosis of vaginal tumors in patients with renal aplasia and/or an ectopic termination of the ureter or metanephric duct remnant, especially when the tumor is in the anterior wall.

[Bilateral persistence of the common mesonephric duct in children. Apropos of a case. Review of the literature]. / Persistance bilatérale du canal mésonéphrotique commun chez l'enfant. A propos d'un cas. Revue de la littérature.

We report a case of bilateral persistence of the common mesonephric duct in a child. This anomaly is an error of implantation of the vas deferens in the distal part of the Wolffian duct. This abnormality is extremely rare (6 cases have been reported in the world literature). The diagnosis is usually incidental during laparotomy or on retrograde cystography (vesico-ureteric and vesico-deferential reflux). It is simple to treat: bilateral deferential ligation in view of the context of multiple malformations, in order to prevent ascending genital infections (prostatitis, epididymitis, testicular abscess). Only one case has been reported in adults, presenting in the form of a septic complication. This diagnosis must be considered in a context of atypical urogenital infection in a subject with other congenital abnormalities.

Splenogonadal fusion.

The fusion between splenic tissue and the left gonad or the derivatives of the left mesonephros is a rare congenital anomaly first described in detail by Pommer in 1887/9 and divided into two forms by Putschar and Manion in 1956. In the first or continuous type a cord of splenic or fibrous tissue connects the spleen and the gonadalmesonephric structures. In the second type the fused splenomesonephric structures have lost continuity with the main spleen. An example of the continuous form is presented and the previous reports are briefly reviewed.