{"id":17600,"date":"2020-10-06T11:09:40","date_gmt":"2020-10-06T10:09:40","guid":{"rendered":"https:\/\/touchendocrinology.com\/?p=17600"},"modified":"2020-10-15T17:05:53","modified_gmt":"2020-10-15T16:05:53","slug":"a-review-of-the-pathology-diagnosis-and-management-of-colloid-goitre","status":"publish","type":"post","link":"https:\/\/touchendocrinology.com\/thyroid\/journal-articles\/a-review-of-the-pathology-diagnosis-and-management-of-colloid-goitre\/","title":{"rendered":"A Review of the Pathology, Diagnosis and Management of Colloid Goitre"},"content":{"rendered":"

Colloid goitre is defined as thyroid enlargement without accompanying disturbance in thyroid function. This is a common pathology, frequently found in clinical practice during a physical or ultrasound examination. Colloid goitre has been classified as nontoxic goitre according to the updated International Classification of Diseases (Table 1<\/span><\/em>).1<\/span>\u00a0Colloid goitre is also known as endemic goitre, simple goitre, nontoxic uninodular goitre, nontoxic multinodular goitre or nodular hyperplasia. They are benign lesions; however, on the ultrasound image, they can mimic malignant lesions.2,3<\/span><\/p>\n

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We conducted searches on the PubMed database for articles published between September 1967 and August 2020 to provide a summary of key issues and updates related to colloid goitre. Search terms included: \u2018colloid goitre\u2019, \u2018diffuse hyperplasia\u2019, \u2018nodular thyroid\u2019, \u2018nontoxic goitre\u2019, \u2018endemic goitre\u2019, \u2018simple goitre\u2019, \u2018nontoxic uninodular goitre\u2019, \u2018nontoxic multinodular goitre\u2019, \u2018nodular hyperplasia\u2019, and \u2018colloid nodule\u2019. In addition, the search was expanded to include terms such as \u2018thyroid nodule\u2019, \u2018thyroid pathology\u2019, \u2018treatment of thyroid pathology\u2019, \u2018thyroid ultrasound\u2019, \u2018thyroid malignancy\u2019, \u2018thyroid cytopathology\u2019, \u2018thyroid evaluation\u2019 and \u2018thyroid nodule management\u2019. Unrelated articles were excluded. This article provides an overview of the aetiology, epidemiology, pathophysiology, histopathology, clinical manifestations and ultrasound features of colloid goitres, as well as differential diagnosis and management.<\/p>\n

Aetiology and epidemiology<\/p>\n

There are many mechanisms and aetiologies that cause colloid goitre (Table 2<\/span><\/em>).2,4<\/span>\u00a0A number of possible factors leading to colloidal goitre include foods that block the hormonal synthesis, mutations in thyroid-stimulating hormone (TSH) receptors, globulin stimulation of thyroid development, growth hormone, insulin-like growth factor 1 (IGF-1) and genetic factors.5,6<\/span> An iodine-deficient diet is also known to lead to colloid nodular goitres. There is evidence that iodine supplementation can decrease the incidence of goitre in these people; however, some cases of longstanding endemic goitres do not always regress with iodine supplementation.4<\/span>\u00a0It has also been suggested that thyroid function control factors, such as C cells, can alter iodine levels, leading to goitre.7<\/span>\u00a0According to some studies, iodine deficiency is associated with a 5\u201310% prevalence of goitre.8,9<\/span>\u00a0The peak age for the onset of goitre is 35\u201350 years, and the ratio of women to men affected by goitre is 3:1.9<\/span>\u00a0There is no correlation between race and the prevalence of goitre.8-10<\/span><\/p>\n

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Pathophysiology and histopathology<\/p>\n

The most important factor of colloid goitre appearance is a reduction in TSH stimulation for a prolonged period of time.11<\/span>\u00a0Pathologically, these are often known as hyperplastic and colloid nodules, sometimes they may also be described as adenomatous. The majority of cystic thyroid lesions are hyperplastic nodules that have undergone extensive liquefactive degeneration by the time they are detected. In cases of diffuse goitre, there will be follicular cell hyperplasia.12<\/span>\u00a0In chronic settings with continued TSH stimulation, some follicles become autonomous and secrete hormones that will depress other areas, which then involute. This leads to multinodular goitre with areas of focal hyperplasia and areas of involution and fibrosis.2,11,13<\/span><\/p>\n

The thyroid gland stores the thyroid hormone in an acellular glycoprotein called colloid. Colloid is present in a variety of forms, from watery and pale to thick and dense, resulting in a broad spectrum of manifestations in cytological preparations. Usually, the colloid is more watery and paler the more active the gland is. The less active it is, the denser the colloid. It is more likely that an abundant colloid is associated with benign nodules.14<\/span><\/p>\n

Histologically, the initial stage of colloid goitre is cellular hyperplasia of the thyroid acini, followed by a micronodular and macronodular formation, which is often indistinguishable from normal thyroid parenchyma, even on histological examination. True thyroid epithelial cysts are rare.15<\/span> Hyperplastic nodules are often subject to liquefying degeneration, accumulating blood, serous fluids and colloidal substances. In this cystic-degenerative process, calcification can occur, which is often coarse and peri-nodular.16<\/span><\/p>\n

Patient history and physical examination<\/p>\n

If a thyroid lesion is palpated, it can be referred to as a nodular goitre, clinically. When there are two or more unilateral or bilateral nodules appearing in the lobes of the thyroid gland, the lesion may be classified as a multinodular goitre. Most patients with colloid goitre are asymptomatic.17<\/span>\u00a0The swelling may be discovered accidentally by the patient or others. On physical examination, there will be a central neck swelling that could be smooth or nodular and moves with swallowing. By palpation of the thyroid, the location, size, consistency and mobility of the nodules can be determined.18<\/span> Multinodular goitre is consistent with benign disease, especially if all nodules have a similar consistency. Some individuals may have compressive symptoms such as dysphagia, dyspnoea and hoarseness of voice due to mechanical compression of the oesophagus, airway and laryngeal nerves by the nearby huge goitre. Goitre can push the trachea or extend retrosternally.19 <\/span>The vocal cords must be examined in cases of hoarseness, or previous surgical intervention. Large thyroids may compress the neck veins, leading to facial congestion and discomfort. Pain is rare, but it may be severe and incremental when there is bleeding in a nodule, and may be associated with sudden changes in the goitre. Any cervical lymphadenopathy that suggests malignancy requires more exclusion workup. In addition, colloid goitre in ectopic thyroid tissue has also been reported.17<\/span><\/p>\n

Ultrasound<\/p>\n

Diffuse hyperplasia<\/p>\n

On ultrasound, a normal thyroid exhibits an isoechoic homogeneous structure with a fine granularity that does not exceed 1 mm. Heterogeneous echostructure is recorded when there is a difference in echodensity compared with the normal background. The concept of a nodular goitre does not always correspond to its morphological definition.20<\/span>\u00a0In ultrasound practice, this term is described as a thyroid lesion, of any size, containing a capsule that could be determined by any modes of visualisation. About 80\u201385% of all thyroid abnormalities are diffuse hyperplasia of the thyroid gland.21,22<\/span>\u00a0Diffuse hyperplasia embodies the following ultrasound attributes:<\/p>\n