Primary malignant fibrous histiocytoma of the thyroid: review of the literature with two new cases.

Primary malignant fibrous histiocytoma of thyroid is extremely rare. Only three cases have been reported. We report two cases of this rare disease. Case 1 was a 70-year-old woman who had Graves' disease and a growing 3.5-cm thyroid nodule with constrictive symptoms. Fine-needle aspiration cytology showed suspicious atypical cells. She had a total thyroidectomy; frozen section showed sarcoma. Final pathology showed malignant fibrous histiocytoma. Case 2 was a 67-year-old woman who had a 5-cm thyroid nodule that rapidly grew, causing tracheal deviation. A diagnostic lobectomy and pathology showed malignant fibrous histiocytoma. She then had a completion total thyroidectomy. Neither patient had metastatic lesions found by whole body gallium scans, computerized tomographic scans, and neck sonography. Both patients had postoperative radiotherapy and were alive and without recurrence at 6 months follow-up.