Difficulty in Follow-Up of Papillary Thyroid Cancer Co-Existent with Hypopituitarism: Case Report and Review of the Literature

Aim: We present an interesting case of papillary thyroid cancer co-existent with hypopituitarism. Case: Fortysix-year-old female was applied with a complaint of painful palpabl lump in the right side of the neck, difficulty swallowing, cough and dyspnea. The patient was diagnosed with type 2 diabetes mellitus 8 years ago, underwent craniotomy for nonfunctioning pituitary adenoma 15 years ago, and received gamma knife 10 years ago. She had been taking insulin glargine and lispro, prednisolone, and levothyroxine (LT4). Physical examination was unremarkable. Pituitary MRI revealed partial empty sella. A solid nodule of 33x27x30 mm with irregular borders and containing microcalcifications in the right thyroid lobe was detected on sonography. Fine needle aspiration cytology revealed “strongly suspicious features for malignancy”. Papillary thyroid carcinoma (PTC) was detected after right lobectomy and then complementary thyroidectomy. Follow-up sonography performed 14 months later than radioactive iodine (RAI) showed an avascular solid area of 30x14x15 mm in the right. We decided to monitor free thyroxine (fT4), thyroglobulin and anti-thyroglobulin levels. LT4 dose was adjusted to keep fT4 level closer to the upper limit of normal. No complications or recurrences were detected. Conclusion: Studies on the follow-up of PTC cases with hypopituitarism are limited. We performed RAI after total thyroidectomy, and treated the patient with LT4 by adjusting fT4 level.