Primary Squamous Cell Carcinoma of Thyroid: A Rare Case Report.

Primary squamous cell carcinoma (PSCC) of the thyroid gland is a rare pathology because there is no squamous epithelium in the thyroid gland. Primary squamous cell carcinoma of the thyroid gland is rare of the thyroid malignancy, accounting for < 1% of all reported cases globally. It is extremely aggressive in nature and has a poor prognosis. We offer a case report of a female patient who presented with neck swelling – Solitary thyroid nodule of right lobe of thyroid; FNAC misinterpreted it as papillary carcinoma of the thyroid and redo FNAC using image guidance showed it to be PSCC. Patient underwent total thyroidectomy with central neck dissection and right modified radical neck dissection, and HPE revealed it to be a case of moderately differentiated squamous cell carcinoma of the thyroid. Our workup is discussed, including the distinction from metastatic illness, etiology of squamous cell carcinoma in thyroid and possible hypothesis behind dedifferentiation and metaplastic theory.