Testicular microlithiasis and undescended testis
Goede, J.
Citation
Goede, J. (2012, January 19). Testicular microlithiasis and undescended testis. Retrieved from https://hdl.handle.net/1887/18389
Version: Corrected Publisher’s Version
License: Licence agreement concerning inclusion of doctoral thesis in the Institutional Repository of the University of Leiden
Downloaded from: https://hdl.handle.net/1887/18389
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Introduction
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Introduction Introduction
Introduction
Undescended testis is one of the most common urological anomalies in boys and is associated with impaired spermatogenesis and a four- to seven-fold increased risk of malignant testicular germ cell tumour. It is categorised as either congenital or acquired.
A congenital undescended testis is a testis which has never been descended and the cause is considered to be multifactorial, including environmental, genetic, endocrine and mechanic factors. Acquired undescended testis is defined as a testis, previously residing in the scrotum, which can no longer be manipulated into a stable, low scrotal position.
It includes high scrotal, inguinal and non-palpable forms. Acquired undescended testis accounts for a substantial portion of orchidopexies in boys aged 2 years or older. The underlying mechanisms of acquired undescended testis remain unclear.
It is estimated that congenital undescended testis is present in 0.7 – 1.0% of boys of 1 year old, and surgical treatment is now recommended for patients as young as 6 months of age. However, there is much uncertainty regarding the management of acquired undescended testis, which is present in 1.5% of prepubertal boys. Usually, at the time of diagnosis the testis is routinely brought down into the scrotum by surgery but a wait- and-see policy provides spontaneous pubertal descent in 57 – 71% of the cases, thus reserving pubertal orchidopexy for cases of non-descent. It is still debatable what the best treatment for acquired undescended testis is.
As there is a direct correlation between testicular volume and testicular function, accurate measurement of testicular volume is essential in the evaluation of boys with undescended testis. Therefore, it is important to have data about the long-term testicular growth of acquired undescended testis after prepubertal orchidopexy as well as after spontaneous descent or pubertal orchidopexy in case of non-descent. Currently, the Prader orchidometer is widely used in clinical settings to obtain testicular volume.
However, ultrasound offers the potential for greater accuracy in testicular measurement.
Unfortunately, normative values of ultrasonographically measured testicular volumes are not available for boys.
The increased risk of developing a testicular malignancy in undescended testis may be related to testicular microlithiasis as in adults testicular microlithiasis has been associated with testicular germ cell tumours and infertility. Testicular microlithiasis are multiple foci (< 3mm) of increased echogenicity without acoustic shadowing which may occur unilaterally or bilaterally. The microliths consist of hydroxyapatite deposits surrounded by concentric layers. Although the exact cause of testicular microlithiasis is unknown, the origin of the microliths is presumed to be related to Sertoli cell dysfunction.
In symptomatic adults, the prevalence of testicular microlithiasis varies between 0.6 and 9%, while in asymptomatic populations prevalences of 2.4% and 5.6% have been found.
However, in boys the prevalence has only been established incidentally in symptomatic patients, and no data are available on the prevalence in a reference population of asymptomatic boys.
Introduction
In this thesis, the following questions regarding testicular microlithiasis and undescended testis will be addressed:
1. What is the clinical relevance of testicular microlithiasis in boys, according to the literature?
2. What are the prevalence rates of testicular microlithiasis in healthy boys and in boys referred for scrotal pathologies?
3. Is the prevalence rate of testicular microlithiasis higher in boys with undescended testis and/or Down syndrome than in healthy boys?
4. What are the normative values for testicular volume in boys from birth to adolescence?
5. Are the volumes of retractile testes comparable to those of fully descended testes?
6. What are the consequences on the long-term testicular growth of acquired undescended testis after spontaneous descent or after pubertal orchidopexy?
7. Is the acquired undescended testis a separate condition or is it actually congenital?
Outline
This thesis deals with various aspects of testicular microlithiasis and undescended testis.
Chapter 1 reviews the paediatric literature on testicular microlithiasis in order to report on its prevalence, its relation to benign and malignant tumours, and the recommended therapy. In addition, a guideline is presented for the follow-up and management of boys with testicular microlithiasis.
Chapter 2 describes testicular microlithiasis in asymptomatic as well as in symptomatic boys. In addition, it addresses the prevalence of testicular microlithiasis in asymptomatic males of 0 – 19 years old, in boys with congenital or acquired undescended testis and in boys referred for scrotal pathology. Subsequently, testicular microlithiasis is described in a cohort of boys with Down syndrome. Finally, testicular microlithiasis is described in one boy with pseudoxanthoma elasticum and in two boys known to have a chromosomal abnormality.
In Chapter 3 testicular volume in a population of healthy boys is described in order to obtain normative values. In addition, testicular volume is analysed in boys with retractile testes.
Chapter 4 describes the natural course and long-term testicular growth of acquired undescended testis after spontaneous descent or pubertal orchidopexy in case of non- descent. This chapter concludes with an overview of the current views on acquired undescended testis.
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