Journal of Clinical Endocrinology & Metabolism, doi:10.1210/jc.2006-0508
The Journal of Clinical Endocrinology & Metabolism Vol. 91, No. 8 2819-2820
Copyright © 2006 by The Endocrine Society
Myxedema Pseudovolvulus
Huy A. Tran and
Aidan Foy
Hunter Area Pathology Service (H.A.T.), John Hunter Hospital, and Department of General Internal Medicine (A.F.), Newcastle Mater Misericordiae Hospital, Hunter Mail Region Centre, Newcastle, New South Wales 2310, Australia
Address all correspondence and requests for reprints to: A/Professor Huy A. Tran, Department of Clinical Chemistry, Hunter Area Pathology Service, John Hunter Hospital, Newcastle, New South Wales 2310, Australia. E-mail: huy.tran{at}hnehealth.nsw.gov.au.
A 45-yr-old woman presented with rapid onset of abdominal pain and distension over 4 h. The pain was constant, dull, and moderately severe with nausea but no vomiting. No bowel motion or flatus had been passed in the previous 24 h. This occurred on a background of recurrent abdominal pain in the previous 8–12 months, which had been intermittently mild in nature. She reported suffering from chronic constipation, which had worsened in the last 4–6 months during which a number of over-the-counter laxatives had been tried with modest success only. There was no significant past medical history, but her health in general had been in a steady decline in the last 4–5 yr, being more withdrawn and less active than previously.
Clinical examination revealed a myxedematous elderly-appearing woman. She was oriented and coherent but slow in response and mentation. Simple arithmetics and calculations were performed correctly. Her pulse rate was 58 beats per minute with generally dry skin. Her rectal temperature was 35.5 C with blood pressure of 120/80 mm Hg recumbent and 115/80 mm Hg upright. Her abdomen was moderately distended and tympanic. Her abdominal girth was 128 cm with general mild tenderness. Bowel sounds were sparse and there was no rebound or shifting dullness. Rectal examination revealed a rectum full of hard and impacted stool. Her Achilles deep tendon reflex had a slow relaxation phase (the so-called hangman’s response). Her abdominal x-ray (Fig. 1
) was worryingly suggestive of cecal volvulus but computerized tomography showed diffuse distension of the abdomen with a grossly distended rectum (Fig. 2, A and B). She was treated conservatively with iv fluid, nasogastric tube insertion, and bowel rest. Her abdominal pain resolved progressively after a rectal manual evacuation followed by regular laxatives. Her TSH was 80.0 IU/liter with an undetectable free T4 level. Her thyroid antithyroperoxidase antibody titer was 1:6400, consistent with autoimmune primary hypothyroidism. T4 therapy was introduced gradually and stabilized at 75 µg daily. Her mental status and general function improved markedly 12 months later with a serum TSH of 1.2 U/liter and free T4 of 17.8 pmol/liter. Her bowel actions have become regular and the abdominal pain has completely resolved.
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FIG. 1. Dilated loops of large bowel in the right iliac fossa (white arrows) with fluid level (black arrow) suggestive of a cecal volvulus. Pneumointestinalis is not observed. Note the extensive fecal loading in the distal colon and rectum.
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FIG. 2. A, Sagittal view of the abdomen using computerized axial tomography showing extensive dilated loops of large bowels extending into the pelvis. This assisted in excluding cecal volvulus. B, Sagittal view of the pelvis revealing the extensive fecal loading in the rectum with surrounding wall edema (black arrow) and dilated loop of large bowel (white arrow), indicating the presence of myxoedema megacolon/rectum.
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Myxedema pseudovolvulus and megacolon are extremely rare manifestations of hypothyroidism. The former is likely to be the end result of myxedematous megacolon. The megacolon is thought to be due to decreased peristalsis and increased edema of the bowel wall (1), which is due to the deposition of hydrophilic glycoprotein in the bowel wall (2). It has also been postulated that neuropathy may develop in the Auerbach’s and Meissner’s plexuses as well as the larger nerve trunks entering the large bowel (3). Although some peristaltic activity is recoverable with T4 replacement therapy, in some cases, atony due to degeneration of the bowel muscle is irreversible (4). With progressive myxedema, the bowel eventually ceases to function, causing gross dilatation of the bowel wall through the intestinal tract, including the rectum (Fig. 2B
). In some cases, this can cause ischemia and pseudomembranous colitis (5). The evolution of the megacolon to true cecal volvulus is not known to occur, although it may be speculated that an edematous focus in the bowel may serve as a pivot upon which the bowels may twist.
Fortunately, the condition should respond well to conservative therapy (6, 7), followed by T4, although in some cases, surgical intervention needs to be considered. Myxedema pseudovolvulus should remain in the differential diagnosis because the radiology of this condition is often indistinguishable from true volvulus. If unrecognized, it can erroneously lead to surgical intervention, a potentially risky procedure in the presence of unrecognized myxedema.
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Footnotes
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Disclosure statement: H.A.T. and A.F. have nothing to declare. There is no conflict of interest pertinent to the publication of this manuscript.
First Published Online May 16, 2006
Received March 6, 2006.
Accepted May 9, 2006.
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References
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- Larsen PR, Davies TF 2003 Hypothyroidism and thyroiditis. In: Larsen PR, Kronenberg MH, Melmed S, Polonsky SK, eds. Williams textbook of endocrinology. 10th ed. Chapter 12. Philadelphia, PA: Saunders, Elsevier Science; 425
- Douglas AC, Jacobson SD 1957 Pathologic changes in adult myxedema: survey of ten necropsies. J Clin Endocrinol Metab 17:1354
- Wells I, Smith B, Hinton M 1977 Acute ileus in myxedema. Br Med J 1:211–212[Medline]
- Duret RL, Bastenie PA 1971 Intestinal disorders in hypothyroidism: clinical and manometric studies. Dig Dis Sci 16:723–727[CrossRef]
- Patel R, Hughes Jr RW 1992 An unusual case of myxedema megacolon with features of ischaemic and pseudomembranous colitis. Mayo Clin Proc 67:369–372[Medline]
- Solano Jr FX, Starling RC, Levey GS 1985 Myxedema megacolon. Arch Intern Med 145:231
- Abbasi AA, Douglass RC, Bissell GW, Chen Y 1975 Myxedema ileus. A form of intestinal pseudo-obstruction. JAMA 234:181–183[Abstract]
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