Endocrine Abstracts

Introduction: Thyrolipoma (focal adenolipoma of thyroid gland) and thyrolipomatosis (diffuse lipomatosis in the gland) are rarely encountered pathologies in daily practice. We reported a case of small thyrolipoma incidentally diagnosed in a multinodular goiter patient.

Case report: A 56 year-old man was admitted to our out-patient clinics with the complaint of a lump in his cervical region. His thyroid function tests were normal. In physical examination, a mobile soft nodule of about 4 cm in the left lobe was realized. In thyroid ultrasonography, multiple nodules with a maximum dimension of 45×30 mm were reported. No pathological lymph nodes were detected. In fine needle aspiration biopsy of the biggest nodule, benign thyrocytes with the presumption of cystic colloidal nodule were reported. Because of the hugeness of the nodule and multiple nodular nature, total thyroidectomy was performed. In thyroidectomy pathology, bilateral multinodular hyperplasia and a thyrolipoma (coexistence of mature adipocytes and thyroid follicular cells in a nodule) in 9×6 mm right lobe nodule were detected. No adipose tissue infiltration other than this lesion was detected in the whole thyroid gland. The patient recovered well after surgery and levothyroxine replacement therapy was initiated.

Conclusions: Thyrolipomas are rare, benign, biologically inactive tumoral lesions of the thyroid gland. Because of their relatively outer localization in the thyroid gland and its fatty nature mimicking parathyroid glands, they might be confused with parathyroid glands intraoperatively.