Solid variant of papillary carcinoma thyroid in a child with no history of radiation exposure
A 12-year-old girl presented with a left sided neck swelling for 6 months and anterior neck swelling for 2 months, which were gradually increasing in size. She was clinically euthyroid. There was no history of any compressive symptoms. Local examination revealed a well-defined 2.5 × 2.5 cm nodule in the left lobe of thyroid and multiple enlarged left cervical lymph nodes. There was no contributory family history. Ultrasound examination of neck revealed enlarged thyroid lobes (L > R) with altered parenchymal echotexture with multiple nodular masses around the left lobe of thyroid and left cervical lymphadenopathy. She underwent a fine needle aspiration cytology examination (FNAC) of the left lobe lesion and the lymph nodes which suggested a differential of hurthle cell neoplasm versus medullary carcinoma thyroid. As a next step she was advised to follow-up with tumor markers for medullary carcinoma thyroid namely serum calcitonin and carcinoembryonic antigen (CEA) which were surprisingly within normal limits (serum calcitonin - 4.15 [normal limit < 11.5] and CEA - 1.7 [normal limits < 5]).\nIn view of the doubtful cytology report, the FNAC was again repeated and it showed features of papillary carcinoma thyroid with metastasis to left cervical lymph nodes. For metastatic work-up 18F-FDG PET/CT was done. It showed a large, irregular hypodense lesion in the enlarged left lobe of thyroid gland measuring 1.8 × 2.5 cm with intense FDG uptake (SUVmax-2.4) suggested as primary site and loco-regional metastasis to multiple left cervical lymph nodes (level II, III, IV, VII) and left supraclavicular lymph nodes, which showed an increased FDG uptake [Figure –]. She underwent total thyroidectomy with left radical neck dissection and histopathologic examination of excised specimen showed grossly enlarged both lobes of thyroid with multiple greyish white areas. Multiple sections examined showed the presence of islands and cords of cells with bizarre, pleomorphic nuclei and dense inflammatory infiltrate and were initially reported as undifferentiated carcinoma with focal papillary areas with tumor reaching up to the capsule. However, since undifferentiated carcinoma is hitherto rarely reported in children, we reviewed the histopathology (HPE) again. It also showed solid nests of cells separated by fibrous septa and foci of calcification, round to oval vesicular nuclei, a moderate amount of eosinophilic cytoplasm and occasional nuclear grooves, features compatible with those of a “solid variant of PTC” [Figure –]. Three weeks after the surgery she was referred for a whole-body radioiodine scan to us and the 24 h image after 2 mCi of radioiodine showed an iodine concentrating remnant with uptake of 0.22%. The child was treated with a dose of 30 mCi for remnant ablation and the post-therapy scan showed no additional iodine avid lesions.