Acute Suppurative Thyroiditis (AST) With Thyroid Abscess: A Rare and Potentially Fatal Neck Infection

Abstract

Thyroid abscess, although rare, is a condition that usually occurs as a sequela of acute suppurative thyroiditis (AST) which is an infection of the thyroid gland. The infrequent occurrence of thyroid abscess is due to the unique anatomical and physiological characteristics of the gland which renders it resistant to infections. Delay in diagnosis and treatment can have adverse outcomes and serious complications such as septicaemia, descending necrotising mediastinitis, extension into deep spaces of the neck, and tracheal or oesophageal perforation. The mainstay of management is a combination of systemic antibiotics along with incision and drainage, and rarely surgery. We report the case of a 37-year-old male with acute suppurative thyroiditis with a thyroid abscess. He underwent incision and drainage of the abscess and was subsequently treated with systemic antibiotics. This condition warrants a prompt and timely diagnosis with appropriate management as it often leads to fatal complications if not diagnosed early.

Keywords: acute suppurative thyroiditis; hypothyroidism; incision and drainage of abscess; pyriform sinus fistula; thyroid abscess.

Figure 1. Ultrasonography image of neck/thyroid

Ultrasonography of neck/thyroid showing heterogeneous nodule measuring 28 × 18 mm in the left lobe with internal calcification (shown in blue arrow). The left thyroid lobe appears to be heterogeneous with increased vascularity.

Figure 2. CECT image of the neck

Contrast-enhanced computed tomography (CECT) neck showing thyroiditis with nodule and a large ill-defined hypo-dense lesion in the left lobe of the thyroid, extending to the isthmus, suggestive of an evolving abscess within the thyroid nodule (shown in blue arrow).

Figure 3. CECT image of neck/thorax

Contrast-enhanced computed tomography (CECT) neck/thorax showing left aryepiglottic fold asymmetrically bulky (shown in orange arrow), left sternocleidomastoid muscle appears bulky and edematous (shown in blue arrow), and obliteration of the left vallecula (shown in yellow arrow).

Figure 4. HRCT chest image

High-resolution computed tomography (HRCT) chest showing cavitating nodules in bilateral lung fields, the largest measuring 3.9 x 2.5 cm in the antero-basal segment of the right lobe (shown in blue arrow).  Multiple small solid nodules were noted in bilateral lung fields, the largest measuring 7 mm in the superior segment of the left lower lobe (shown in orange arrow).

Figure 5. Histopathological image

The section shows thyroid tissue with dense neutrophilic infiltration forming an abscess (H&E, 40x)