A large nonmetastatic anaplastic thyroid cancer with complete thyroidal confinement

Area of Science:

• Oncology
• Pathology

Background:

• Anaplastic thyroid cancer (ATC) is a rare and highly aggressive malignancy.
• It accounts for approximately 2% of thyroid cancers but causes nearly 50% of thyroid cancer deaths.
• The prognosis for ATC is typically poor, with a median survival of 5 months.

Observation:

• A case of a 56-year-old male patient with a large, 9.5 cm right thyroid mass was diagnosed with ATC.
• The tumor was well-circumscribed, with no extrathyroidal extension or lymphovascular invasion.
• Histopathological examination revealed undifferentiated cells, necrosis, and loss of specific markers, but also a focal well-differentiated component confirming thyroid origin.

Findings:

• Surgical resection (total thyroidectomy with neck dissection) was performed, removing the large tumor.
• All 73 lymph nodes examined were negative for metastasis.
• The patient received postsurgical adjuvant concurrent radiation and chemotherapy, remaining disease-free at 9 months.

Implications:

• This case highlights an unusual presentation of ATC with a large tumor size but relatively mild pathological behavior.
• It suggests that aggressive multimodal treatment, including surgery and adjuvant therapy, can lead to long-term survival even in large ATC cases.
• Further research into factors influencing ATC behavior and treatment response is warranted.