Intrathyroidal Thymoma: A Diagnostic Challenge

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Intrathyroidal thymoma is a rare entity, often mistaken for common thyroid conditions.
• Diagnostic challenges arise from its unusual location within the thyroid gland.

Observation:

• A 58-year-old woman presented with an incidentally found, exophytic left thyroid nodule (TR 3).
• Initial fine-needle aspiration suggested a neoplastic process.

Findings:

• Histopathology confirmed intrathyroidal thymoma (Type B2) with extensive necrosis.
• Immunohistochemistry validated the thymoma diagnosis.

Implications:

• This case emphasizes the need to include intrathyroidal thymoma in the differential diagnosis of atypical thyroid nodules.
• Surgical resection and histopathological examination are crucial for definitive diagnosis, despite preoperative identification difficulties.