Four cases of clear cell lymphoma were studied by means of light and electron microscopy, enzyme-histochemistry, and E- and EAC-rosette formation. On light microscopic examination the tumors were seen to be composed mainly of round, oval, or slight irregular cells with water-clear, abundant cytoplasm. The neoplastic cells has round, oval, or convoluted nuclei with fine, evenly dispersed chromatin and one or more small but distinct nucleoli. On electron microscopic examination the clear cell lymphoma were characterized by lymphoid cells with striking electron lucent cytoplasm with few organelles. According to E-rosette test and enzyme-histochemical findings, the investigators proposed that the clear cell lymphoma may be derived from T-cell lineages. Differentiated diagnoses of clear cell lymphoma from B-immunoblastic sarcoma, pleomorphic cell lymphoma, clear cell sarcoma, and clear carcinomas derived from lung, ovary, or kidney were discussed.