Encapsulated papillary variant of medullary carcinoma of thyroid with extensive cystic change: an extremely rare presentation

Papillary variant of medullary carcinoma of the thyroid is an unusual subtype with many diagnostic challenges. The authors report a case of papillary variant of thyroid medullary carcinoma in a 37-year-old female, who presented with complaints of pain in the thyroid nodule for the latter two months. Contrast enhanced computed tomography (CECT) neck revealed an enlarged and heterogeneously enhancing left lobe of thyroid. This was followed by hemithyroidectomy for suspicion of colloid goitre. Gross examination of the cut surface of the thyroid parenchyma had a sponge like appearance. On histopathology a diagnosis of encapsulated papillary variant of medullary carcinoma thyroid was made with the help of special stains and immunohistochemistry (IHC).