Papillary carcinoma masquerading as clinically toxic adenoma in very young children.

Autonomously functioning thyroid nodules (AFTN) are extremely rare in children. Malignancy may be rarely found in hyperfunctioning 'hot' nodules in adults. However, there are limited reports of AFTNs in young children presenting as or developing malignancy in future. We report here two young children aged < 6 years old at the time of diagnosis as having an AFTN, which eventually turned out to be papillary carcinoma of thyroid (PTC) on follow-up. A 2-month-old baby had a right-sided neck swelling since birth. On examination, the baby had clinical and biochemical features of thyrotoxicosis. On sonography, and subsequently on 99mTc-pertechnetate thyroid scan, a hot nodule was found. Patient was treated with carbimazole for 5 years. In spite of euthyroidism achieved, the nodule continuously grew in size. Thyroid cytology was inconclusive, hence hemithyroidectomy was performed and histopathology turned out to be PTC. Another 5-year-old female child had a large right-sided AFTN on thyroid scan. She was treated with radioiodine; however, like the previous case, the nodule started growing in size. She subsequently underwent near total thyroidectomy and histology was reported as PTC. In the light of this report that shows that solitary hyperfunctioning nodules in very young children have high chance of malignancy, we recommend hemithyroidectomy as the treatment of choice.