Endocrine Abstracts

Background: Anaplastic thyroid carcinoma (ATC) is a rare, highly aggressive thyroid malignancy characterized by rapid progression and poor prognosis. Early diagnosis remains challenging as ATC can mimic benign thyroid conditions. This case describes an aggressive course of ATC in a young woman with painful neck swelling and an initial diagnosis of Papillary thyroid cancer (PTC).

Case: A 41-year-old woman presented with a 4-day history of painful anterior neck swelling. She was clinically and biochemically euthyroid, with no retrosternal or compressive symptoms. Examination revealed a tender, multinodular 45g thyroid mass without regional lymphadenopathy. An initial impression of subacute thyroiditis was made, and she was scheduled for thyroid ultrasound and fine needle aspiration cytology (FNAC). At one-week review, she had worsening neck swelling with severe headache. Neck ultrasound revealed thyroid malignancy with nodal involvement, FNAC was malignant, suggestive of PTC (Bethesda category III). Chest and abdominal CT scans excluded distant metastases. She underwent a difficult thyroidectomy due to tumor friability. Ten days postoperatively, histology confirmed anaplastic thyroid carcinoma with local invasion. A follow-up chest CT scan revealed pulmonary and bony metastases. She was scheduled for emergency radiotherapy but developed acute respiratory distress, required ICU admission, and died within four weeks of presentation.

Conclusion: This case highlights the diagnostic challenges of ATC, its aggressive progression, and tendency to mimic benign or differentiated thyroid lesions. Early recognition, prompt diagnostic workup, and multidisciplinary management are critical, though prognosis often remains poor despite intervention.