Investigations:
Imaging findings: Ultrasonography of neck was done for further evaluation. Ultrasonography revealed absence of thyroid gland in expected anatomical location (fig: 2). No history of thyroid surgery was present. A soft tissue structure measuring 3.0 x 2.6 x 1.7 cm was seen in suprahyoid location abutting floor of mouth in midline. Internal vascularity was seen within the structure. Echotexture of the structure was mildly heterogeneous (fig: 2). The patient was counselled about possibility of lingual thyroid. But the parents were too apprehensive and wanted to rule out malignancy. An ultrasound guided fine needle aspiration cytology was done on patient’s request. In cytology, follicular cells were seen confirming the structure to be thyroid gland. Lymphocytes were seen impinging on the follicular cells (fig: 3). Diagnosis of chronic lymphocytic thyroiditis was made.
Thyroid function test: Thyroid function test was done which showed hypothyroidism. TSH- 12.3 mIU/mL (normal range 0.4 – 4 mIU/mL) free T4- 0.9 ng/dL (normal range 0.5 – 1.2 ng/dL) and T3 – 135 ng/dL (normal range 100 – 200 ng/dl). Anti TPO antibody level was 95IU/mL (normal value < 26 IU/mL). Patient was diagnosed as case of chronic lymphocytic thyroiditis.