Figure 1
Transabdominal ultrasound
Androgen insensitivity syndrome
SectionUroradiology & genital male imaging
Case TypeClinical Cases
AuthorsDr. Najibullah Rasouly, Dr. Ahmad Reshad Faizi, Dr. Mer Mahmood Shah Hoshang.
Connected authors
22 years, female
Clinical History
A 23-year-old female patient presented with the main complaint of primary amenorrhea. To rule out Mullerian abnormalities, obstetrician sends her for MRI pelvis.
Imaging Findings
Transabdominal pelvis ultrasound demonstrated absence of uterus, ovaries and presence of testis without gonadal cyst in the bilateral inguinal canal. T2 MRI of pelvis confirmed absence of uterus and bilateral ovaries. Well-defined ovoid structures hyperintense in T2 fat sat images in the bilateral inguinal canal resemble testes.
Discussion
Androgen insensitivity syndrome is an X-linked recessive disorder caused by mutations of the androgen receptor, described by John Morris in 1953 for the first time [1]. AIS is a rare disorder, with the prevalence estimated to be between 1 in 20400 and 1 in 99100. AIS is divided into two variants, complete androgen insensitivity syndrome (CAIS) and partial androgen insensitivity syndrome (PAIS) depending on the absence or presence of virilization. In the complete form, there are no functional androgen receptors. CAIS patients have a female phenotype with male karyotype and despite testicular production of testosteron and dihydrotestosterone they do not develop either male genitalia or male secondary sexual characters; since Sertoli cells produce Mullerian-inhibiting factor, Mullerian structures are not developing. Testes are located usually in the inguinal canal, sublabial, or intra-abdominal, and commonly adjoined by small cystic pouches that are thought to be remnants of the Mullaerian or Wolffian ducts. PAIS differ in that there is some functional androgen receptor activity, leading to partially masculinized genital tract structures. The typical phenotype in PAIS is a micropenis, severe hypospadias, and a bifid scrotum which may contain gonads. In either complete or partial AIS, the psychosexual gender of the patient is wholly female [1, 3].
Based on the age of presentation signs and symptoms are different. Primary amenorrhea in adolescence or inguinal swellings in an infant. A female adolescent with the disorder has breast development and a pubertal growth spurt at the appropriate age, but no menses. Development of oestrogen-dependent secondary sexual characteristics occurs as the result of excess aromatization of androgens. [4]
In all cases, ultrasound is the first imaging modality ordered to locate the suspected undescended testes. It has the advantage that there is no radiation exposure, making it ideal in the paediatric population. It is readily accessible at all hospitals. It is sensitive in localizing testicular tissue; its efficacy is decreased when the testes are situated above the inguinal ring. [1, 3]
The most common imaging modality implemented is MRI. It shows 100 % accuracy in detecting Mullerin anomalies. CT with contrast can greatly help to narrow down the differential in certain cases. The main drawback of CT is the use of ionizing radiation. Radionuclide imaging can also be used to assess for scrotal disease. However, it is not as commonly used due to the poor anatomic detail and exposure to ionizing radiation. [2, 3].
Diagnosis of CAIS is obtained when a male karyotype is found in individuals with a female phenotype. [1]
Based on the age of presentation signs and symptoms are different. Primary amenorrhea in adolescence or inguinal swellings in an infant. A female adolescent with the disorder has breast development and a pubertal growth spurt at the appropriate age, but no menses. Development of oestrogen-dependent secondary sexual characteristics occurs as the result of excess aromatization of androgens. [4]
In all cases, ultrasound is the first imaging modality ordered to locate the suspected undescended testes. It has the advantage that there is no radiation exposure, making it ideal in the paediatric population. It is readily accessible at all hospitals. It is sensitive in localizing testicular tissue; its efficacy is decreased when the testes are situated above the inguinal ring. [1, 3]
The most common imaging modality implemented is MRI. It shows 100 % accuracy in detecting Mullerin anomalies. CT with contrast can greatly help to narrow down the differential in certain cases. The main drawback of CT is the use of ionizing radiation. Radionuclide imaging can also be used to assess for scrotal disease. However, it is not as commonly used due to the poor anatomic detail and exposure to ionizing radiation. [2, 3].
Diagnosis of CAIS is obtained when a male karyotype is found in individuals with a female phenotype. [1]
Differential Diagnosis List
Complete androgen insensitivity syndrome (testicular feminization syndrome).
Mayer-Rokitansky-Kuster-Hauser syndrome
Swyer syndrome
Final Diagnosis
Complete androgen insensitivity syndrome (testicular feminization syndrome).
References
[1] 1. Nezzo, M., De Visschere, P., T'Sjoen, G., Weyers, S., & Villeirs, G. (2013) Role of imaging in the diagnosis and management of complete androgen insensitivity syndrome in adults. Case reports in radiology. (PMID: 23762728)
[2] 2. Nakhal, R. S., Hall-Craggs, M., Freeman, A., Kirkham, A., Conway, G. S., Arora, R., .. & Creighton, S. M. (2013) Evaluation of retained testes in adolescent girls and women with complete androgen insensitivity syndrome.Radiology,. 268(1), 153-160 (PMID: 23533290)
[3] 3. Tank, J., Knoll, A., Gilet, A., & Kim, S (2015) ). Imaging characteristics of androgen insensitivity syndrome. Clinical imaging. (PMID: 25721709)
[4] Hughes IA et al. (2012) Androgen insensitivity syndrome. The Lancet 380(9851):1419-28 (PMID: 22698698)
Case information
| URL: | https://www.eurorad.org/case/13527 |
| DOI: | 10.1594/EURORAD/CASE.13527 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
Transabdominal ultrasound
Transabdominal ultrasound (Low frequency convex array probe) demonstrate absence of uterus and ovaries.
Figure 3
Karyotype
Karyotype of the same patient demonstrate presence of XY chromosome.
Figure 4
Sagittal T2
T2 sagittal image shows absence of Mullerian structures (red arrow).
Figure 5
Axial T2
The axial T2-weighted image shows left testis and right testis in the inguinal canals bilaterally (red arrows).
Figure 6
T2 Transverse
Axial T2 image shows absence of Mullerian structures.
Transabdominal ultrasound
Transabdominal ultrasound (High frequency linear array probe) shows the
presence of the left testis in the inguinal canal.
FMIC, Radiology Department, Kabul , Afghanistan
FMIC, Radiology Department, Kabul , Afghanistan
Transabdominal ultrasound(High frequency linear array probe) shows the
presence of the right testis in the inguinal canal.
FMIC, Radiology Department, Kabul , Afghanistan
FMIC, Radiology Department, Kabul , Afghanistan
Transabdominal ultrasound
Transabdominal ultrasound (Low frequency convex array probe) demonstrate absence of uterus and ovaries.
FMIC, Radiology Department, Kabul, Afghanistan
FMIC, Radiology Department, Kabul, Afghanistan
Karyotype
Karyotype of the same patient demonstrate presence of XY chromosome.
FMIC, Pathology Department, Kabul, Afghanistan
FMIC, Pathology Department, Kabul, Afghanistan
Sagittal T2
T2 sagittal image shows absence of Mullerian structures (red arrow).
FMIC, Radiology Department , Kabul , Afghanistan
FMIC, Radiology Department , Kabul , Afghanistan
Axial T2
The axial T2-weighted image shows left testis and right testis in the inguinal canals bilaterally (red arrows).
FMIC, Radiology Department, Kabul , Afghanistan
FMIC, Radiology Department, Kabul , Afghanistan
T2 Transverse
Axial T2 image shows absence of Mullerian structures.
FMIC, Radiology Department , Kabul , Afghanistan
FMIC, Radiology Department , Kabul , Afghanistan