Incidental Discovery of a Pure Intra-thyroid Lipoma Associated with Contralateral Follicular Adenoma

Lipomas are benign mesenchymal neoplasms composed of mature adipose tissue, most frequently found in subcutaneous regions. We report a case of a pure intra-thyroid lipoma. A 55-year-old Moroccan woman presented with a longstanding cervical mass. Clinical examination revealed a goitre, and thyroid function tests showed a euthyroid profile. Cervical ultrasound revealed a large right lobar thyroid nodule and a 6 mm left-sided nodule classified as EU-TIRADS 3, with no suspicious features. The patient underwent a total thyroidectomy after discussion of management options; the patient preferred definitive surgical management. Histopathological examination demonstrated a follicular adenoma occupying the entire right lobe, while the left lobe contained a 6 mm, well-circumscribed, encapsulated lipomatous lesion composed entirely of mature adipocytes, with no associated thyroid tissue. Only histopathological images are available for inclusion. This case highlights the rarity of pure intra-thyroid lipoma and emphasises the role of careful histopathological assessment in distinguishing fat-containing thyroid lesions.