To the Editor.
—In their recent article, Parker et al1 stated that distant metastasis in cases of papillary thyroid cancer (PTC) typically involves "the lung, bone, or liver" and, in reviewing 1346 reported PTC cases, they found only two (0.15%) examples of brain metastasis. In a recently completed study2 of 859 patients with PTC, treated at the Mayo Clinic, Rochester, Minn, during a 25-year period and followed for up to 39 years, 11 patients (1.3%) with brain metastases were identified. In 40 patients developing postoperative metastasis, the principal sites of involvement were lungs (70%), mediastinum (24%), bone (23%), and brain (15%). Of 56 patients dying of PTC, 11 patients (20%) died as a consequence of metastasis to the brain or the spinal cord.Both of the patients described by Parker et al1 were males; one patient was found to have brain metastasis 33 years after the initial