We studied the clinical and radiological features of pulmonary metastases present in 4 out of 22 patients with medullary carcinoma of thyroid. Two patients presented with common metastases: macronodules in one, and micronodules in the other one. The other two patients presented initially with reticulonodular perihilar lesions on chest X-ray, leading to the diagnosis of sarcoidosis in both of them. The observation of such pulmonary metastases is original: initially latent, they progress very slowly, and they correspond to a lymphangitic spread of the tumour with amyloid deposition in peribronchovascular structures without alveolar involvement, as shown in one of our cases with pathologic study.