Question 30.2

Created on Tue, 06/06/2017 - 05:13
Last updated on Thu, 08/31/2017 - 22:31
Pass rate: 40%
Highest mark: 8.3

Other SAQs in this paper

Other SAQs on this topic

With respect to the images depicted below:

Give the diagnosis. (10% marks)

List three associated biochemical abnormalities. (30% marks)

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College answer

a)

Acromegaly

b)

Hyperglycaemia (Diabetes mellitus)
Hypercalcaemia
Hypercalciuria
Low cortisol
Hypernatraemia (diabetes insipidus)

Discussion

Now, I don't want to get into any sort of legal trouble by reproducing the images which the college decided to withhold as a part of their "official" papers, but reliable sources report that the images used in this question were ripped straight from Wikipedia. Instead of re-using these images (which would arguably be completely legitimate, as they are covered by essentially the same Creative Commons license as the rest of this site) I have sourced others. In case one requires the college originals, they can be viewed in Chanson et al (2008)

The images I have used came from this weird alterna-health website where annoying popups tried to warn me about "Never Eat These Three Fatigue-Causing Foods" etc. Clearly these authors are not the original source of the photographic progression of male faces, which demonstrate the gradual changes associated with acromegaly. The hand pictures came from another severely ad-polluted site (Medindia.com). I hope these are unequivocal. No other answer should be possible for a).

b) affords more variation. Acromegaly is associated with a whole host of clinical features, of which biochemical abnormalities are only one part. Molitch (1992) lists a whole lot of these, but the article is paywalled. Instead one can get Melmed Shlomo's 2006 NEJM piece from tripod.com. It's just as good. In fact there is a table (Table 1, Clinical Features orf Acromegaly) which lists everything you could ever think of which might be associated witht his disease, from the local effects of pituitary adenoma to things like narcolepsy and galactorrhoea. The whole table is reproduced here.

Pituitary tumour effect
  • Visual-field defects (bitemporal hemianopia)
  • Cranial-nerve palsy (usually 3rd nerve)
  • Headache
Skeletal effects
  • "Acral enlargement" - basically, "acral" is a term used to refer to the extremities, particulalry fingers and toes. "Acromegaly at a basic level is a disease of big hands and feet.
  • Large stature, "gigantism"
  • Arthralgias and arthritis
  • Carpal tunnel syndrome
  • Acroparesthesia (fingers and toes again)
  • Hypertrophy of the frontal bone of the skull, giving rise to a prominent brow ridge

Muscular effects

  • Proximal myopathy

Cutaenous manifestations

  • Hyperhidrosis
  • Oily texture
  • Skin tags
  • Prognathism
  • Jaw malocclusion

Airway consequences

  • Prognathism
  • Jaw malocclusion
  • Abnormally large larynx (thus, cuff leak with normal-sized tubes)
  • Large tongue
  • Enlarged thyroid (gets in the way of tracheostomy)
  • Large nasal polyps frustrate nasal intubation
  • Large stature makes ETT position difficult (i.e. it may not reach far enough into the trachea)

Respiratory effects

  • Sleep apnea (central and obstructive)
  • Narcolepsy
  • Restrictive disease due to kyphosis/scoliosis

Cardiovascular effects

  • Left ventricular hypertrophy
  • Asymmetric septal hypertrophy
  • Cardiomyopathy
  • Hypertension
  • Congestive heart failure
  • Mitral and aortic regurgitation

Electrolyte, endocrine and metabolic abnormalities

  • Menstrual abnormalities
  • Galactorrhea
  • Decreased libido, impotence, low levels of sex hormone–binding globulin
  • Low renin, cortisol and aldosterone levels 
  • Hyperglycaemia (impaired insulin sensitivity)
  • Hypercalcemia
  • Hypernatremia (due to DI)

Renal problems

  • Obstructive uropathy (prostatomegaly)
  • Kidney enlargement (may be reported as hydronephrosis)
  • Hypercalciuria

Haematological problems

  • Hepatosplenomegaly

References

Philippe Chanson and Sylvie Salenave - AcromegalyOrphanet Journal of Rare Diseases 2008, 3:17. doi:10.1186/1750-1172-3-17

Molitch, M. E. "Clinical manifestations of acromegaly.Endocrinology and metabolism clinics of North America 21.3 (1992): 597-614.

Melmed, Shlomo. "Acromegaly." New England Journal of Medicine 355.24 (2006): 2558-2573.