Thyroid lymphoepithelial nodule.

Area of Science:

• Endocrinology
• Pathology
• Surgical Oncology

Background:

• Benign lymphoepithelial lesions of the thyroid are uncommon in adults and often associated with other thyroid conditions.
• These lesions are typically found adjacent to tumors or thyroiditis.

Purpose of the Study:

• To report a unique case of a solitary thyroid nodule exhibiting benign lymphoepithelial morphology.
• To emphasize the importance of recognizing this rare entity to avoid misdiagnosis.

Main Methods:

• A case study of a 56-year-old woman with a growing thyroid nodule.
• Surgical resection of the thyroid nodule.
• Histopathological examination including immunohistochemistry (cytokeratin 5/6, cytokeratin 7).

Main Results:

• A 0.5-cm solid nodule with benign lymphoepithelial morphology was identified, distinct from a co-existing follicular adenoma.
• Immunohistochemistry confirmed the benign nature of both the epithelial and lymphoid components.
• Absence of Hassal's corpuscles and calcifications was noted.

Conclusions:

• Thyroid benign lymphoepithelial nodules are rare but important to recognize.
• These nodules can be mistaken for other thyroid micronodules, including malignant types.
• Accurate diagnosis is essential to differentiate from thyroid carcinoma.