A rapid immunoperoxidase method for pathological diagnosis of occult thyroid carcinoma

The authors report four unusual cases of clinically occult carcinoma of the thyroid. Exploratory excision of osseous metastatic lesions was performed for diagnosis in Patients 1 and 2, and fine needle aspiration of cervical metastatic lesions was used for diagnosis in Patients 3 and 4. A definite diagnosis of thyroid cancer could not be made by hematoxylin and eosin staining in Patient 2, nor by fine needle aspiration in Patient 3. However, the diagnosis of thyroid cancer in both patients was made using the rapid immunoperoxidase method with an antibody against thyroglobulin. The rapid immunoperoxidase method reported in this paper requires only about 5 minutes. Hence, this rapid staining method may be routinely applied to definitive identification of the thyroid as the source of metastatic lesions, prior to surgery.