We report a case of Langerhans cell histiocytosis (histiocytosis X) in a 36-year-old female with an euthyroid nodular goitre as the rare initial presentation. She subsequently developed a pathological fracture of the lumbar spine which was initially thought to be due to malignant infiltration, possibly from metastatic thyroid carcinoma. Open vertebral biopsy and total thyroidectomy were performed. Histological features of histiocytic proliferation with erythrophagocytosis were found in both the thyroid gland and in the involved vertebral body. The diagnosis of histiocytosis X was made on the basis of the positive immunoperoxidase staining of the histiocytic cells with S-100 and peanut agglutinin (PNA) as well as the clinical picture. Despite systemic chemotherapy with low dose corticosteroids and vinblastine, diabetes insipidus with a suprasellar mass occurred three years post thyroidectomy. Successful management of this uncommon disease is difficult to conduct and evaluate at the present time.