Clear cell adenocarcinoma of the colon

A case of clear cell adenocarcinoma of the colon is reported. The histological examination of both the surgical specimen and of the metastases at necropsy showed columnar or polygonal cells with vesicular nuclei. The cytoplasm was usually clear with multiple, often empty looking vacuoles. From a panel of histochemical and immunohistochemical reactions, carcinoembryonic antigen and tissue polypeptide antigen showed strong positivity. The histochemical and immunohistochemical differential diagnosis with another common clear cell tumour, namely clear cell renal adenocarcinoma, is discussed.