Epidermal Cyst Mimicking Thyroid Cancer Metastasis

Area of Science:

• Nuclear medicine
• Oncology
• Dermatology

Background:

• Thyroid cancer metastasis can present with varied uptake patterns on radioactive iodine scans.
• Accurate localization of abnormal findings is crucial for patient management.

Observation:

• A patient with metastatic thyroid cancer showed diffuse lung uptake and focal axillary uptake post-131I therapy.
• SPECT/CT identified the axillary abnormality as a subcutaneous, oval-shaped lesion.

Findings:

• Pathological examination confirmed the axillary lesion to be an epidermal cyst.
• The findings highlight the importance of correlating imaging findings with pathological diagnoses.

Implications:

• This case underscores the need to differentiate benign findings from metastatic disease in post-treatment scans.
• Careful radiological assessment is essential to avoid misinterpreting benign lesions as cancer recurrence.