Endocrine Abstracts

Synopsis: Thyroid cancer with concomitant thyrotoxicosis is variably reported to be rare. Malignancy occurs as postoperative incidental finding of a small malignant focus in Graves’ disease, as part of a toxic multinodular or a toxic adenoma. We report two cases of large toxic multinodular goiters with metastasis diagnosed preoperatively as follicular neoplasm and confirmed postoperatively as differentiated thyroid cancer. Review of literature, pathophysiology and treatment strategies will be discussed.

Case 1: A 49 year old female presented with twelve year history of enlarging goiter and mass in the sternal notch which developed over one year. Examination revealed a large multinodular goiter measuring 12×12 cm with 7×7 cm mass in the sternal notch. Investigations revealed follicular neoplasm on fine needle aspiration biopsy and T3 toxicosis. A 1.6×1.8 cm functioning nodule in the superolateral right lobe was demonstrated on thyroid scintigraphy. She underwent total thyroidectomy and excision of the manubrial mass. Histopathology showed follicular variant of papillary cancer with metastasis to the manubrium.

Case 2: A 71 year old female presented with recurrent thyroid nodules of 21 year duration. She had three thyroid surgeries in the past which revealed follicular cancer. She was lost to follow-up after each surgery and received no subsequent treatment. She again consulted for recurrence of the thyroid masses but no symptoms of hypo/hyperthyroidism, obstruction or voice changes. Examination revealed a large multinodular goiter measuring 10×6 cm which yielded follicular neoplasm on fine needle aspiration biopsy. TSH was suppressed at 0.008 mIU/l (NV: 0.3–3.8). Free T4 was elevated at 36.2 pmol/l (NV: 11–24). Thyroid scintigraphy showed functioning thyroid tissues with a conglomerate size of 8×5.6 cm. Chest imaging revealed lung metastasis. She is presently being treated with Methimazole 40 mg daily in preparation for thyroidectomy.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.