Poorly differentiated thyroid carcinoma arising from substernal goiter: a case report.

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Poorly differentiated thyroid carcinoma (PDTC) is a rare malignancy, comprising 2-4% of thyroid neoplasms.
• Substernal goiter (SG) is an enlarged thyroid gland extending below the thoracic inlet; malignant neoplasms arising from SG are exceptionally rare (2-3% of cases).

Observation:

• A 54-year-old female presented with dysphagia, dyspnea, cervical swelling, and anorexia.
• Radiological and clinical examinations led to total thyroidectomy with lymph node dissection.
• Microscopic examination revealed an infiltrative PDTC with insular, trabecular, and solid formations, characterized by specific cellular and nuclear features, and areas of necrosis.

Findings:

• The final diagnosis was multifocal poorly differentiated thyroid carcinoma arising from a substernal goiter.
• Histopathological features presented diagnostic challenges due to tumor heterogeneity.
• Diagnosis was confirmed using the Turin Criteria, emphasizing histopathological examination.

Implications:

• This case highlights the importance of thorough histopathological evaluation of thyroid nodules, especially in substernal goiters.
• Early and accurate diagnosis of PDTC is crucial for effective management.
• The study underscores the diagnostic complexities associated with rare thyroid malignancies.