Hyperthyroidism caused by a toxic intrathoracic goiter with a normal-sized cervical thyroid gland

Area of Science:

• Endocrinology
• Nuclear Medicine
• Thoracic Surgery

Background:

• Hyperthyroidism is commonly associated with cervical thyroid enlargement.
• Intrathoracic goiters are enlarged thyroid glands located in the chest.
• Rarely, hyperthyroidism can stem from an intrathoracic goiter even with a normal cervical thyroid.

Observation:

• A case of hyperthyroidism was presented, caused by an intrathoracic goiter.
• The cervical thyroid gland was of normal size in this patient.
• The intrathoracic goiter showed high uptake of radioactive iodine (131I) and technetium-99m pertechnetate.

Findings:

• The toxic intrathoracic goiter avidly accumulated radioisotopes.
• The cervical thyroid gland exhibited minimal radioisotope uptake.
• Diagnostic imaging is key to identifying the source of hyperthyroidism.

Implications:

• Chest roentgenograms and radioisotope scans are recommended for hyperthyroidism cases without cervical thyroid enlargement.
• These imaging modalities can help diagnose rare toxic intrathoracic goiters.
• Early diagnosis of intrathoracic goiters is essential for appropriate management and treatment.