Testicular volume
Testicular volume is assessed using an orchidometer; a sequential series of beads ranging in size from 1 mL to 35 mL (see Image 1).
Conduct the examination in a warm environment, with the patient lying on their back.
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Gently isolate the testis and distinguish it from the epididymis. Then stretch the scrotal skin, without compressing the testis
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Use your orchidometer to make a manual side-by-side comparison between the testis and beads (see Image 2)
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Identify the bead most similar in size to the testis, while making allowance not to include the scrotal skin
Normal testicular volume ranges
Clinical notes
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Asymmetry between testes is common (e.g. 15 mL versus 20 mL) and usually not medically significant
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Asymmetry is sometimes more marked following unilateral testicular damage or with large varicoceles
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Testes are roughly proportional to body size
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Low testicular volume suggests impaired spermatogenesis
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Small testes (< 4 mL) from mid puberty are a consistent feature of Klinefelter syndrome
Examination of secondary sexual characteristics
Gynecomastia
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Gynecomastia is the excessive and persistent development of benign glandular tissue evenly distributed in a sub-areolar position of one or both breasts (see Image 3)
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Can cause soreness and considerable embarrassment
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Common during puberty, usually resolves in later adolescence
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Causes include increased estrogen, low testosterone, various medications, marijuana, androgen abuse and abnormal liver function
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Distinguish glandular tissue from sub-areolar fat in obese subjects
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Rare secondary causes include hypothalamic/pituitary and adrenal/testis tumours (oestrogen excess)
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Rapidly developing gynecomastia may indicate a testicular tumour
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In contrast to gynecomastia, breast cancer can be located anywhere within the breast tissue and feels firm or hard
Onset of puberty
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Average onset is 12-13 years
Virilisation
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Facial and body hair development
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Muscle development
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Penile growth
Penile Growth
Image 1: Orchidometer
Why use an Orchidometer?
Testicular volume is important in the assessment of normal development and diagnosis of androgen deficiency, infertility and Klinefelter syndrome.
Image 2 – Gynecomastia
(Photo courtesy of Mr G Southwick, Melbourne Institute of Plastic Surgery)
Examination of testis and scrotal contents
Examination of penile abnormalities
Clinical review
Clinical review by Dr Darren Katz, Men’s Health Melbourne
