Medullary thyroid carcinoma with breast metastasis: Two case reports

Area of Science:

• Oncology
• Endocrinology
• Pathology

Background:

• Medullary thyroid carcinoma (MTC) is an aggressive thyroid cancer subtype.
• MTC commonly metastasizes to the lungs, liver, or bone.
• Breast metastasis from MTC is exceptionally rare.

Observation:

• Two MTC patients presented with breast lumps post-initial treatment.
• Pathologic analysis confirmed MTC characteristics in breast nodules.
• Genetic mutations in metastatic breast lesions were analyzed.

Findings:

• One patient underwent wide local excision with no relapse in 14 months.
• The second patient's breast nodule grew and then stabilized.
• Serum calcitonin levels proved valuable for disease evaluation.

Implications:

• MTC can exhibit indolent behavior despite its aggressive nature.
• Reoperation may be considered for localized MTC recurrence or resectable metastasis.
• Further research into MTC molecular features is crucial for improved diagnosis and treatment strategies.