[Thyroid cancer with signs of C- and A-cell differentiation]

The paper reports a case of thyroid cancer in a female patient aged 56 operated on for nodular euthyroid goiter. The tumor had a mixed histological structure of medullary-follicular cancer and resembled malignant hemangioendothelioma. Electron microscopy detected tumor cells of A- and C-cell type as well as nondifferentiated elements. The tumor contained deposits of amorphous mass deprived of tinctorial properties characteristic of APUD-amyloid and having fine-fibrillar material produced by tumor C-cells.