A 60-year-old man with a history of neck irradiation presents with a rapidly enlarging thyroid mass causing hoarseness and dysphagia. Biopsy shows sheets of highly pleomorphic cells with frequent mitoses, areas of tumor necrosis, and spindle cell components. The most likely diagnosis carries which prognosis?

• A 90% 5-year survival with surgery alone
• B Excellent prognosis with radioiodine therapy
• C Cure rate exceeding 70% with chemoradiation
• D Median survival of 3–6 months despite treatment ✓

Explanation

The presentation describes anaplastic (undifferentiated) thyroid carcinoma, the most aggressive thyroid malignancy. It is uniformly fatal with a median survival of approximately 3–6 months after diagnosis regardless of therapy. Anaplastic carcinoma does not concentrate radioiodine and is largely resistant to current multimodal treatment. The tumor is thought to arise from dedifferentiation of pre-existing well-differentiated carcinoma.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.