- •Contents
- •Contributors
- •1 Introduction
- •2.1 Posterior Compartment
- •2.2 Anterior Compartment
- •2.3 Middle Compartment
- •2.4 Perineal Body
- •3 Compartments
- •3.1 Posterior Compartment
- •3.1.1 Connective Tissue Structures
- •3.1.2 Muscles
- •3.1.3 Reinterpreted Anatomy and Clinical Relevance
- •3.2 Anterior Compartment
- •3.2.1 Connective Tissue Structures
- •3.2.2 Muscles
- •3.2.3 Reinterpreted Anatomy and Clinical Relevance
- •3.2.4 Important Vessels, Nerves, and Lymphatics of the Anterior Compartment
- •3.3 Middle Compartment
- •3.3.1 Connective Tissue Structures
- •3.3.2 Muscles
- •3.3.3 Reinterpreted Anatomy and Clinical Relevance
- •3.3.4 Important Vessels, Nerves, and Lymphatics of the Middle Compartment
- •4 Perineal Body
- •References
- •MR and CT Techniques
- •1 Introduction
- •2.1 Introduction
- •2.2.1 Spasmolytic Medication
- •2.3.2 Diffusion-Weighted Imaging
- •2.3.3 Dynamic Contrast Enhancement
- •3 CT Technique
- •3.1 Introduction
- •3.2 Technical Disadvantages
- •3.4 Oral and Rectal Contrast
- •References
- •Uterus: Normal Findings
- •1 Introduction
- •References
- •1 Clinical Background
- •1.1 Epidemiology
- •1.2 Clinical Presentation
- •1.3 Embryology
- •1.4 Pathology
- •2 Imaging
- •2.1 Technique
- •2.2.1 Class I Anomalies: Dysgenesis
- •2.2.2 Class II Anomalies: Unicornuate Uterus
- •2.2.3 Class III Anomalies: Uterus Didelphys
- •2.2.4 Class IV Anomalies: Bicornuate Uterus
- •2.2.5 Class V Anomalies: Septate Uterus
- •2.2.6 Class VI Anomalies: Arcuate Uterus
- •2.2.7 Class VII Anomalies
- •References
- •Benign Uterine Lesions
- •1 Background
- •1.1 Uterine Leiomyomas
- •1.1.1 Epidemiology
- •1.1.2 Pathogenesis
- •1.1.3 Histopathology
- •1.1.4 Clinical Presentation
- •1.1.5 Therapy
- •1.1.5.1 Indications
- •1.1.5.2 Medical Therapy and Ablation
- •1.1.5.3 Surgical Therapy
- •1.1.5.4 Uterine Artery Embolization (UAE)
- •1.1.5.5 Magnetic Resonance-Guided Focused Ultrasound
- •2 Adenomyosis of the Uterus
- •2.1 Epidemiology
- •2.2 Pathogenesis
- •2.3 Histopathology
- •2.4 Clinical Presentation
- •2.5 Therapy
- •3 Imaging
- •3.2 Magnetic Resonance Imaging
- •3.2.1 Magnetic Resonance Imaging: Technique
- •3.2.2 MR Appearance of Uterine Leiomyomas
- •3.2.3 Locations, Growth Patterns, and Imaging Characteristics
- •3.2.4 Histologic Subtypes and Forms of Degeneration
- •3.2.5 Differential Diagnosis
- •3.2.6 MR Appearance of Uterine Adenomyosis
- •3.2.7 Locations, Growth Patterns, and Imaging Characteristics
- •3.2.8 Differential Diagnosis
- •3.3 Computed Tomography
- •3.3.1 CT Technique
- •3.3.2 CT Appearance of Uterine Leiomyoma and Adenomyosis
- •3.3.3 Atypical Appearances on CT and Differential Diagnosis
- •4.1 Indications
- •4.2 Technique
- •Bibliography
- •Cervical Cancer
- •1 Background
- •1.1 Epidemiology
- •1.2 Pathogenesis
- •1.3 Screening
- •1.4 HPV Vaccination
- •1.5 Clinical Presentation
- •1.6 Histopathology
- •1.7 Staging
- •1.8 Growth Patterns
- •1.9 Treatment
- •1.9.1 Treatment of Microinvasive Cervical Cancer
- •1.9.2 Treatment of Grossly Invasive Cervical Carcinoma (FIGO IB-IVA)
- •1.9.3 Treatment of Recurrent Disease
- •1.9.4 Treatment of Cervical Cancer During Pregnancy
- •1.10 Prognosis
- •2 Imaging
- •2.1 Indications
- •2.1.1 Role of CT and MRI
- •2.2 Imaging Technique
- •2.2.2 Dynamic MRI
- •2.2.3 Coil Technique
- •2.2.4 Vaginal Opacification
- •2.3 Staging
- •2.3.1 General MR Appearance
- •2.3.2 Rare Histologic Types
- •2.3.3 Tumor Size
- •2.3.4 Local Staging
- •2.3.4.1 Stage IA
- •2.3.4.2 Stage IB
- •2.3.4.3 Stage IIA
- •2.3.4.4 Stage IIB
- •2.3.4.5 Stage IIIA
- •2.3.4.6 Stage IIIB
- •2.3.4.7 Stage IVA
- •2.3.4.8 Stage IVB
- •2.3.5 Lymph Node Staging
- •2.3.6 Distant Metastases
- •2.4 Specific Diagnostic Queries
- •2.4.1 Preoperative Imaging
- •2.4.2 Imaging Before Radiotherapy
- •2.5 Follow-Up
- •2.5.1 Findings After Surgery
- •2.5.2 Findings After Chemotherapy
- •2.5.3 Findings After Radiotherapy
- •2.5.4 Recurrent Cervical Cancer
- •2.6.1 Ultrasound
- •2.7.1 Metastasis
- •2.7.2 Malignant Melanoma
- •2.7.3 Lymphoma
- •2.8 Benign Lesions of the Cervix
- •2.8.1 Nabothian Cyst
- •2.8.2 Leiomyoma
- •2.8.3 Polyps
- •2.8.4 Rare Benign Tumors
- •2.8.5 Cervicitis
- •2.8.6 Endometriosis
- •2.8.7 Ectopic Cervical Pregnancy
- •References
- •Endometrial Cancer
- •1.1 Epidemiology
- •1.2 Pathology and Risk Factors
- •1.3 Symptoms and Diagnosis
- •2 Endometrial Cancer Staging
- •2.1 MR Protocol for Staging Endometrial Carcinoma
- •2.2.1 Stage I Disease
- •2.2.2 Stage II Disease
- •2.2.3 Stage III Disease
- •2.2.4 Stage IV Disease
- •4 Therapeutic Approaches
- •4.1 Surgery
- •4.2 Adjuvant Treatment
- •4.3 Fertility-Sparing Treatment
- •5.1 Treatment of Recurrence
- •6 Prognosis
- •References
- •Uterine Sarcomas
- •1 Epidemiology
- •2 Pathology
- •2.1 Smooth Muscle Tumours
- •2.2 Endometrial Stromal Tumours
- •3 Clinical Background
- •4 Staging
- •5 Imaging
- •5.1 Leiomyosarcoma
- •5.2.3 Undifferentiated Uterine Sarcoma
- •5.3 Adenosarcoma
- •6 Prognosis and Treatment
- •References
- •1.1 Anatomical Relationships
- •1.4 Pelvic Fluid
- •2 Developmental Anomalies
- •2.1 Congenital Abnormalities
- •2.2 Ovarian Maldescent
- •3 Ovarian Transposition
- •References
- •1 Introduction
- •4 Benign Adnexal Lesions
- •4.1.1 Physiological Ovarian Cysts: Follicular and Corpus Luteum Cysts
- •4.1.1.1 Imaging Findings in Physiological Ovarian Cysts
- •4.1.1.2 Differential Diagnosis
- •4.1.2 Paraovarian Cysts
- •4.1.2.1 Imaging Findings
- •4.1.2.2 Differential Diagnosis
- •4.1.3 Peritoneal Inclusion Cysts
- •4.1.3.1 Imaging Findings
- •4.1.3.2 Differential Diagnosis
- •4.1.4 Theca Lutein Cysts
- •4.1.4.1 Imaging Findings
- •4.1.4.2 Differential Diagnosis
- •4.1.5 Polycystic Ovary Syndrome
- •4.1.5.1 Imaging Findings
- •4.1.5.2 Differential Diagnosis
- •4.2.1 Cystadenoma
- •4.2.1.1 Imaging Findings
- •4.2.1.2 Differential Diagnosis
- •4.2.2 Cystadenofibroma
- •4.2.2.1 Imaging Features
- •4.2.3 Mature Teratoma
- •4.2.3.1 Mature Cystic Teratoma
- •Imaging Findings
- •Differential Diagnosis
- •4.2.3.2 Monodermal Teratoma
- •Imaging Findings
- •4.2.4 Benign Sex Cord-Stromal Tumors
- •4.2.4.1 Fibroma and Thecoma
- •Imaging Findings
- •4.2.4.2 Sclerosing Stromal Tumor
- •Imaging Findings
- •4.2.5 Brenner Tumors
- •4.2.5.1 Imaging Findings
- •4.2.5.2 Differential Diagnosis
- •5 Functioning Ovarian Tumors
- •References
- •1 Introduction
- •2.1 Context
- •2.2.2 Indications According to Simple Rules
- •References
- •CT and MRI in Ovarian Carcinoma
- •1 Introduction
- •2.1 Familial or Hereditary Ovarian Cancers
- •3 Screening for Ovarian Cancer
- •5 Tumor Markers
- •6 Clinical Presentation
- •7 Imaging of Ovarian Cancer
- •7.1.2 Peritoneal Carcinomatosis
- •7.1.3 Ascites
- •7.3 Staging of Ovarian Cancer
- •7.3.1 Staging by CT and MRI
- •Imaging Findings According to Tumor Stages
- •Value of Imaging
- •7.3.2 Prediction of Resectability
- •7.4 Tumor Types
- •7.4.1 Epithelial Ovarian Cancer
- •High-Grade Serous Ovarian Cancer
- •Low-Grade Serous Ovarian Cancer
- •Mucinous Epithelial Ovarian Cancer
- •Endometrioid Ovarian Carcinomas
- •Clear Cell Carcinomas
- •Imaging Findings of Epithelial Ovarian Cancers
- •Differential Diagnosis
- •Borderline Tumors
- •Imaging Findings
- •Differential Diagnosis
- •Recurrent Ovarian Cancer
- •Imaging Findings
- •Differential Diagnosis
- •Value of Imaging
- •Malignant Germ Cell Tumors
- •Dysgerminomas
- •Imaging Findings
- •Differential Diagnosis
- •Immature Teratomas
- •Imaging Findings
- •Malignant Transformation in Benign Teratoma
- •Imaging Findings
- •Differential Diagnosis
- •Sex-Cord Stromal Tumors
- •Granulosa Cell Tumors
- •Imaging Findings
- •Sertoli-Leydig Cell Tumor
- •Imaging Findings
- •Ovarian Lymphoma
- •Imaging Findings
- •Differential Diagnosis
- •7.4.3 Ovarian Metastases
- •Imaging Findings
- •Differential Diagnosis
- •7.5 Fallopian Tube Cancer
- •7.5.1 Imaging Findings
- •Differential Diagnosis
- •References
- •Endometriosis
- •1 Introduction
- •2.1 Sonography
- •3 MR Imaging Findings
- •References
- •Vagina and Vulva
- •1 Introduction
- •3.1 CT Appearance
- •3.2 MRI Protocol
- •3.3 MRI Appearance
- •4.1 Imperforate Hymen
- •4.2 Congenital Vaginal Septa
- •4.3 Vaginal Agenesis
- •5.1 Vaginal Cysts
- •5.1.1 Gardner Duct Cyst (Mesonephric Cyst)
- •5.1.2 Bartholin Gland Cyst
- •5.2.1 Vaginal Infections
- •5.2.1.1 Vulvar Infections
- •5.2.1.2 Vulvar Thrombophlebitis
- •5.3 Vulvar Trauma
- •5.4 Vaginal Fistula
- •5.5 Post-Radiation Changes
- •5.6 Benign Tumors
- •6.1 Vaginal Malignancies
- •6.1.1 Primary Vaginal Carcinoma
- •6.1.1.1 MRI Findings
- •6.1.1.2 Lymph Node Drainage
- •6.1.1.3 Recurrence and Complications
- •6.1.2 Non-squamous Cell Carcinomas of the Vagina
- •6.1.2.1 Adenocarcinoma
- •6.1.2.2 Melanoma
- •6.1.2.3 Sarcomas
- •6.1.2.4 Lymphoma
- •6.2 Vulvar Malignancies
- •6.2.1 Vulvar Carcinoma
- •6.2.2 Melanoma
- •6.2.3 Lymphoma
- •6.2.4 Aggressive Angiomyxoma of the Vulva
- •7 Vaginal Cuff Disease
- •7.1 MRI Findings
- •8 Foreign Bodies
- •References
- •Imaging of Lymph Nodes
- •1 Background
- •3 Technique
- •3.1.1 Intravenous Unspecific Contrast Agents
- •3.1.2 Intravenous Tissue-Specific Contrast Agents
- •References
- •1 Introduction
- •2.1.1 Imaging Findings
- •2.1.2 Differential Diagnosis
- •2.1.3 Value of Imaging
- •2.2 Pelvic Inflammatory
- •2.2.1 Imaging Findings
- •2.3 Hydropyosalpinx
- •2.3.1 Imaging Findings
- •2.3.2 Differential Diagnosis
- •2.4 Tubo-ovarian Abscess
- •2.4.1 Imaging Findings
- •2.4.2 Differential Diagnosis
- •2.4.3 Value of Imaging
- •2.5 Ovarian Torsion
- •2.5.1 Imaging Findings
- •2.5.2 Differential Diagnosis
- •2.5.3 Diagnostic Value
- •2.6 Ectopic Pregnancy
- •2.6.1 Imaging Findings
- •2.6.2 Differential Diagnosis
- •2.6.3 Value of Imaging
- •3.1 Pelvic Congestion Syndrome
- •3.1.1 Imaging Findings
- •3.1.2 Differential Diagnosis
- •3.1.3 Value of Imaging
- •3.2 Ovarian Vein Thrombosis
- •3.2.1 Imaging Findings
- •3.2.2 Differential Diagnosis
- •3.2.3 Value of Imaging
- •3.3 Appendicitis
- •3.3.1 Imaging Findings
- •3.3.2 Value of Imaging
- •3.4 Diverticulitis
- •3.4.1 Imaging Findings
- •3.4.2 Differential Diagnosis
- •3.4.3 Value of Imaging
- •3.5 Epiploic Appendagitis
- •3.5.1 Imaging Findings
- •3.5.2 Differential Diagnosis
- •3.5.3 Value of Imaging
- •3.6 Crohn’s Disease
- •3.6.1 Imaging Findings
- •3.6.2 Differential Diagnosis
- •3.6.3 Value of Imaging
- •3.7 Rectus Sheath Hematoma
- •3.7.1 Imaging Findings
- •3.7.2 Differential Diagnosis
- •3.7.3 Value of Imaging
- •References
- •MRI of the Pelvic Floor
- •1 Introduction
- •2 Imaging Techniques
- •3.1 Indications
- •3.2 Patient Preparation
- •3.3 Patient Instruction
- •3.4 Patient Positioning
- •3.5 Organ Opacification
- •3.6 Sequence Protocols
- •4 MR Image Analysis
- •4.1 Bony Pelvis
- •5 Typical Findings
- •5.1 Anterior Compartment
- •5.2 Middle Compartment
- •5.3 Posterior Compartment
- •5.4 Levator Ani Muscle
- •References
- •Evaluation of Infertility
- •1 Introduction
- •2 Imaging Techniques
- •2.1 Hysterosalpingography
- •2.1.1 Cycle Considerations
- •2.1.2 Technical Considerations
- •2.1.3 Side Effects and Complications
- •2.1.5 Pathological Findings
- •2.1.6 Limitations of HSG
- •2.2.1 Cycle Considerations
- •2.2.2 Technical Considerations
- •2.2.2.1 Normal and Abnormal Anatomy
- •2.2.3 Accuracy
- •2.2.4 Side Effects and Complications
- •2.2.5 Limitations of Sono-HSG
- •2.3 Magnetic Resonance Imaging
- •2.3.1 Indications
- •2.3.2 Technical Considerations
- •2.3.3 Limitations
- •3 Ovulatory Dysfunction
- •4 Pituitary Adenoma
- •5 Polycystic Ovarian Syndrome
- •7 Uterine Disorders
- •7.1 Müllerian Duct Anomalies
- •7.1.1 Class I: Hypoplasia or Agenesis
- •7.1.2 Class II: Unicornuate
- •7.1.3 Class III: Didelphys
- •7.1.4 Class IV: Bicornuate
- •7.1.5 Class V: Septate
- •7.1.6 Class VI: Arcuate
- •7.1.7 Class VII: Diethylstilbestrol Related
- •7.2 Adenomyosis
- •7.3 Leiomyoma
- •7.4 Endometriosis
- •References
- •MR Pelvimetry
- •1 Clinical Background
- •1.3.1 Diagnosis
- •1.3.2.1 Cephalopelvic Disproportion
- •1.3.4 Inadequate Progression of Labor due to Inefficient Contraction (“the Powers”)
- •2.2 Palpation of the Pelvis
- •3 MR Pelvimetry
- •3.2 MR Imaging Protocol
- •3.3 Image Analysis
- •3.4 Reference Values for MR Pelvimetry
- •5 Indications for Pelvimetry
- •References
- •MR Imaging of the Placenta
- •2 Imaging of the Placenta
- •3 MRI Protocol
- •4 Normal Appearance
- •4.1 Placenta Variants
- •5 Placenta Adhesive Disorders
- •6 Placenta Abruption
- •7 Solid Placental Masses
- •9 Future Directions
- •References
- •Erratum to: Endometrial Cancer
Congenital Malformations
of the Uterus
Justus Roos, Gligor Milosevic, Martin Heubner,
and Rahel A. Kubik-Huch
Contents
1 |
Clinical Background\ |
|
61 |
1.1 |
Epidemiology\ |
|
61 |
1.2 |
Clinical Presentation\ |
|
62 |
1.3 |
Embryology\ |
|
63 |
1.4 |
Pathology\ |
|
63 |
2 |
Imaging\ |
|
64 |
2.1 |
Technique\ |
|
64 |
2.2 Classes of Müllerian Duct Anomalies |
|
|
|
|
(MDA)\ |
|
66 |
References\ |
|
73 |
Abstract
Congenital malformations of the uterus, also termed Müllerian duct anomalies (MDA), are an uncommon, but often treatable, cause of infertility. Estimates of its frequency vary widely owing to different patient populations, nonstandardized classification systems, and differences in diagnostic data acquisition. Because normal pregnancies can occur in women with MDA and the anomalies are mostly discovered in cases of patients presenting with infertility, the reported prevalence of MDA in the general population is probably underestimated.
J. Roos, MD
Institute of Radiology, Luzerner Kantonsspital, CH-6000, Luzern, Switzerland
G. Milosevic, MD • R.A. Kubik-Huch, MD, MPH (*) Institute of Radiology, Kantonsspital Baden AG, CH-5404, Baden, Switzerland
e-mail: rahel.kubik@ksb.ch
M. Heubner, MD
Department of Gynaecology and Obstetrics, Kantonsspital Baden AG, CH-5404, Baden, Switzerland
1\ Clinical Background
1.1\ Epidemiology
Congenital malformations of the uterus, also termed Müllerian duct anomalies (MDA), are an uncommon, but often treatable, cause of infertility. Estimates of its frequency vary widely owing to different patient populations, nonstandardized classification systems, and differences in diagnostic data acquisition. Because normal pregnancies can occur in women with MDA and the anomalies are mostly discovered in cases of patients presenting with infertility, the reported prevalence of MDA in the general population is probably underestimated.
The overall published data suggest a prevalence range of uterovaginal anomalies of around
Med Radiol Diagn Imaging (2017) |
61 |
DOI 10.1007/174_2017_1, © Springer International Publishing AG
Published Online: 11 February 2017
62 |
J. Roos et al. |
|
|
1–10% (Acién 1997; Ashton et al. 1988; Homer et al. 2000; Raga et al. 1997; Saleem 2003; Simón et al. 1991; Troiano and McCarthy 2004; Chan et al. 2011a) in the general population among women with normal and abnormal fertility. Arcuate and septate uteri appear to be the most common malformations in an unselected population (Dreisler and Stampe 2014). While conceiving is a minor problem for the majority of women with MDA, the risk of pregnancy loss is truly associated with MDA. Its prevalence in women with repeated miscarriage is considered to be around 5–13% (Homer et al. 2000; Raga et al. 1997; Chan et al. 2011a; Clifford et al. 1994; Nahum 1998; Raziel et al. 1994) and up to 25% in women with combined infertility and recurrent miscarriage (Chan et al. 2011a). No racial predilection is noted in the literature.
1.2\ Clinical Presentation
Mild forms of MDA, especially arcuate uteri, may never be diagnosed. Major forms of MDA may become clinically evident at different ages depending on their specific characteristics and associated disorders. The distribution among the different classes of MDA and their clinical presentations is summarized in Table 1. In the newborn/infant age,
an initial presentation of a palpable abdominal or pelvic mass due to a uterine or/and vaginal obstruction causing intraluminal fluid retention is possible. In the adolescent age group, a delayed menarche or primary amenorrhea with or without fluid retention in the uterus (hematometra) and/or vagina (hematocolpos) may present as a painful intra-abdominal tumor in case of obstruction or complete obliteration. Some patients also have cyclical pain, usually due to retrograde menstruation through the fallopian tubes. The most common MDA often become significant for the first time in the childbearing age. Patients can present with various problems of infertility, repeated spontaneous abortions, premature delivery, fetal intrauterine growth retardation, and difficulties during delivery like breech presentation or transverse lie (Zlopasa et al. 2007).
By understanding the defective embryological development, one can understand the potential for the presence of associated congenital malformations of other organ systems. Most frequently, renal malformations like renal agenesis or ectopia can occur. Much less frequent are bony malformations – most of them occur in a complex of varying symptoms – like abnormal scapula, supernumerary or fused ribs, vertebral malsegmentation, fusion of the vertebral column (i.e., Klippel–Feil syndrome), and radiocarpal hypoplasia. The nonrandom association
Table 1 Distribution among the different classes of MDA and their clinical presentations
Müllerian duct anomalies |
|
|
|
|
|
(MDA) |
Influence on reproductive/obstetric outcome |
Other major associations |
|||
|
Spontaneous |
Premature |
Fetal survival rate |
|
|
|
abortion |
delivery |
|
|
|
Class I: Dysplasia (4–10%) |
No potential for reproduction |
|
|
||
Class II: Unicornuate uterus |
50%a (41–62%) |
15% |
(10–20%) |
40% (38–57%) |
Renal agenesis 67% |
(5–20%) |
|
|
|
|
|
|
|
|
|
|
|
Class III: Uterus didelphys |
45% (32–52%) |
38% |
(20–45%) |
55% (41–61%) |
Longitudinal vaginal |
(5–11%) |
|
|
|
|
septum 75% |
Class IV: Bicornuate uterus |
30% (28–35%) |
20% |
(14–23%) |
60% (57–63%) |
High cervical |
(10–39%) |
|
|
|
|
incompetence 38% |
|
|
|
|
|
|
Class V: Septate uterus |
65% (26–94%) |
20% |
(9–33%) |
30% (10–75%) |
Vaginal septum 25% |
(34–55%) |
|
|
|
|
|
Class VI: Arcuate uterus (7%) |
Mostly compatible with normal-term gestation |
|
|||
|
|
|
|
|
|
Class VII: DES-exposed uterus |
Increased |
Increased |
Decreased |
Cervical anomalies |
|
|
|
|
|
|
44% |
All percentage data are pooled from the current literature (Simón et al. 1991; Troiano and McCarthy 2004; Nahum 1998; Rennell 1979; Chan et al. 2011b); values in brackets represent percentage ranges
Congenital Malformations of the Uterus |
63 |
|
|
of MDA, renal agenesis/ectopia, and cervicothoracic somite dysplasia are subsumed under the so-called MURCS associations (Pittock et al. 2005). Although other malformations such as cardiac defects have been described, it remains unclear if some of the associated malformations are caused in the same development field or if early exposure to teratogenic agents was causative (Pittock et al. 2005). The literature does not show increased mortality for patients carrying an MDA compared to the general population, whereas the morbidity may be increased in some specific types of MDA causing obstructed Müllerian systems with the presence of hematosalpinx (retention of blood in the fallopian tubes), hematocolpos (retention of blood in the vagina), or retrograde menses causing the potential problem of endometriosis.
Once an MDA is suggested based on evidence from patient history and physical examination, the next diagnostic step includes an imaging workup, which often detects the underlying anomaly and guides further (surgical) interventions. Apart from the precise anatomic evaluation of the female genital tract, attention should be paid to associated malformations (e.g., of ureter or pelvic vessels), as this additional information might impact upon therapeutic measures, especially reconstructive or corrective surgery.
1.3\ Embryology
The understanding of the embryogenesis of the urogenital female tract is of paramount importance to understand the pathogenesis of the different types of MDA. The female reproductive system develops from the two paired Müllerian ducts (synonym: paramesonephric ducts) that start off in the embryonal mesoderm lateral to each Wolffian duct (synonym: mesonephric duct). The paired Müllerian ducts develop in medial and caudal directions, and the cranial part remains nonfused and forms the fallopian tubes. The caudal part fuses to a single canal forming the uterus and the upper two thirds of the vagina. This is called lateral fusion. In a process called
vertical fusion, the intervening midline septum of both ducts undergoes regression. The caudal part of the vagina arises from the sinovaginal bulb and fuses with the lower fused Müllerian ducts. The ovaries originate from the gonadal ridge, a completely different tissue than the mesoderm, forming both the urinary and genital systems. Hence, associated malformations of the kidney, but not of the ovaries, are frequently observed together with MDA. Pathogenesis of Müllerian duct anomalies can be basically classified into the presence of agenesis, hypoplasia, and defects in vertical and lateral fusion of the paired ducts.
In1988,theAmericanSocietyforReproductive
Medicine (ASRM; formerly known as American Fertility Society) (1988) presented a consensus in classification of uterovaginal anomalies and published a schematization system that is widely accepted among specialists. Other used classification systems are referenced (Buttram and Gibbons 1979; Rock and Schlaff 1985; Rock 2000). A more recent classification was proposed in 2013 by the
European Society of Human Reproduction and Embryology (ESHRE) and the European Society
for Gynaecological Endoscopy (ESGE)
(Grimbizis et al. 2013), in an attempt to improve the characterization of anomalies which did not fit into any group of the older classifications. Its reliability in clinical practice and effect on reproductive outcome still warrant further scientific evaluation, as it has been reported to lead to possible overdiagnosis and unnecessary operative treatment of septate uteri in cases which would have been classified as normal or arcuate uteri according to the ASRM classification (Ludwin and Ludwin 2015).
Although most Müllerian duct anomalies occur sporadically, there is a known association with in utero exposure to teratogenic agents such as diethylstilbestrol (DES) or thalidomide (Kaufman et al. 2000). Currently there are no known specific patterns of inheritance.
1.4\ Pathology
Whatever steps in embryogenesis are defective, different types of MDA can occur. The ASRM