Incidentally detected ectopic thyroid in juxta cardiac location-Imaging and pathology

Area of Science:

• Endocrinology
• Developmental Biology
• Surgical Pathology

Background:

• Ectopic thyroid tissue arises from developmental arrest during thyroid descent, typically along the thyroglossal duct.
• While ectopic thyroid tissue can occur in the chest, abdomen, or pelvis, intrathoracic and particularly intracardiac locations are exceptionally rare.
• Right ventricular ectopic thyroid tissue is the most frequently reported intracardiac location.

Observation:

• A case of incidentally detected ectopic thyroid tissue adjacent to the left atrium is presented.
• The patient, with a history of renal oncocytoma, presented with weight loss and flank pain, leading to imaging studies.
• Computed tomography (CT) revealed a heterogeneously enhancing mass near the left atrium, prompting further investigation.

Findings:

• Radiological investigations were crucial in differentiating the mass from other potential diagnoses, such as paraganglioma.
• The mass was surgically resected.
• Histologic examination confirmed the mass to be a hyperplastic thyroid nodule.

Implications:

• This case expands the known spectrum of ectopic thyroid tissue locations, underscoring its potential for extrathyroidal occurrence.
• It highlights the diagnostic challenges and the importance of considering ectopic thyroid tissue in the differential diagnosis of mediastinal masses, even in rare locations.
• Surgical resection is curative, and histologic confirmation remains the gold standard for diagnosis.