Eunuchoid body shape

Eunuch, in the etymological sense, is derived from the Greek words “eune,” meaning “bed,” and “ekho,” meaning protector/keeper. Eunuchoidism refers to a disorder of male gonadal insufficiency noted after castration. This state of androgenic failure results in various eunuchoid body shapes, depending on the timing of androgen withdrawal – congenital, peripubertal, or postpubertal.

Classification of eunuchoid body shape or habitus

Timing of castration (androgen withdrawal) and eunuchoid body shape or habitus

A: depicts a eunuch who developed hypogonadism very early on in life. B: depicts the peripubertal onset of eunuchoidism, with a broad pelvis and narrow shoulders. C: shows the postpubertal onset of eunuchoidism (maintains the narrow pelvis and broad shoulders of a normal male)

Features of Eunuchoidism

• Eunuchoid stature
• Unbroken voice with an absent Adam’s apple
• Poorly developed upper and lower extremity musculature
• Absent or poorly developed male pattern hair growth (mustache and beard)
• Infantile male genitalia
• Absence of baldness (remember that male pattern hair loss is testosterone-dependent)

What is the classic eunuchoid body shape?

This includes having relatively long arms and legs in relation to the trunk. Either the length of the lower part of the body (lower extremity) or 1/2 extended arm length (upper extremity) is typically greater than the length of the upper body. 

Also, their average height lies a little above the normal height of corresponding population groups. However, it should be noted that these measurements can vary depending on the individual. In addition, patients with peripubertal onset of eunuchoidism tend to present with a narrow biacromial width (narrow shoulders) and a wide bitrochanteric diameter (broad pelvis). 

A simple mnemonic for remembering the proportions of a eunuchoid habitus is that a eunuch is “a standing giant, but a sitting dwarf”. These eunuchoid body proportions are attributable to delayed fusion of the epiphyseal plate in the setting of testosterone deficiency.

What are the eunuchoid body proportions?

This is depicted in the line diagram below

• The ratio of upper body (A) to lower body (B) is less than 0.88. A/B <0.88
• The ratio of a full arm span (C  x 2 ) to full body height (A+B) is greater than 1.0. Formula = 2C/A+B >1.0
• A = Distance from the vertex to the symphysis pubis (upper body)
• B = Distance from the symphysis pubis to the heel (lower body)
• C = Distance from the sternum to the hand (50% arm span)
• Also, note the narrow shoulders and broad pelvis of this eunuch.

References

Rochira V, Kara E, Carani C. The endocrine role of estrogens on human male skeleton. Int J Endocrinol. 2015;2015:165215.

Images(s) Courtesy

• Labhart, Alexis. Clinical endocrinology: theory and practice. Springer Science & Business Media, 2012.
• MyEndoconsult