Ossifying fibromyxoid tumour of the neck clinically mimicking a primary neoplasm of the thyroid gland.

We present a 50-year-old male patient with an ossifying fibromyxoid tumour (OFMT) of the prethyroidal soft parts infiltrating the thyroid gland in coincidence with recurrent goitre, 20 years after strumectomy. The tumour, initially misdiagnosed as thyroid carcinoma and malignant schwannoma respectively, was histologically composed of typical solid cell-formations and shelly-like mature bone at the periphery. In addition, in the tissue adjacent to the tumour some foreign body granulomas with suture material and small proliferating nerves were present as a residual of the preceding strumectomy. We regard this finding as an indication of nerve sheat origin of OFMT. Follow up of 3 years after total thyroidectomy and local irradiation shows the patient free of recurrent and metastatic disease.