Double thyroid ectopia (with incidental papillary thyroid microcarcinoma) (2010: 8b).

Area of Science:

• Endocrinology
• Surgical Pathology
• Head and Neck Surgery

Background:

• Thyroid ectopia is a rare congenital condition where thyroid tissue is found outside its normal location.
• Ectopic thyroid tissue can present as a neck mass, often in the midline or lateral neck.
• Diagnosis typically involves imaging and pathological examination.

Observation:

• A 45-year-old male presented with a slow-growing left submandibular mass.
• Imaging revealed an absent orthotopic thyroid gland and heterogeneous masses with cystic components and calcifications in the left submandibular and tongue base regions.
• These findings were consistent with double thyroid ectopia, originating from central and lateral thyroid anlages.

Findings:

• Pathology confirmed an ectopic thyroid goiter in the left submandibular space.
• An incidental papillary microcarcinoma was discovered within the ectopic thyroid tissue.
• Scintigraphy confirmed the presence of ectopic thyroid tissue in the left tongue base.

Implications:

• This case highlights the importance of considering thyroid ectopia in the differential diagnosis of neck masses, even in adults.
• The presence of papillary microcarcinoma in ectopic thyroid tissue underscores the need for thorough pathological evaluation.
• Understanding the embryological origins of thyroid ectopia is crucial for accurate diagnosis and management.