Study note

Progression of simple goitre from diffuse hyperplasia to nodularity

THE CONTEXT

Repeated growth stimulation and tissue injury produce the structural changes of nodular goitre.

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Persistent growth stimulation produces diffuse hyperplasia. All lobules contain active follicles, and iodine uptake is uniform.

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This diffuse hyperplastic stage may persist but is reversible when stimulation ceases.

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Fluctuating stimulation subsequently produces a mixture of active and inactive lobules.

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Active lobules become more vascular and hyperplastic until haemorrhage causes central necrosis, leaving a surrounding rind of active follicles.

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Necrotic lobules coalesce into nodules containing either iodine-free colloid or new but inactive follicles.

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Repeated cycles produce nodular goitre. Most nodules are inactive, with active follicles confined to the internodular tissue.

NEETx

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