A small number of nuclear heterogeneous cells in pleural effusion means that there are cells with abnormal nuclei in pleural effusion. These nuclear heterogeneous cells can originate from inflammation or tumors, and have a certain tendency to malignant changes, and the discovery of nuclear heterogeneous cells should be vigilant for the occurrence of lung tumors or chest wall tumors. The nucleus of nuclear heterogeneous cells is larger than that of normal cells, and the shape and staining of the nucleus differ greatly, with megakaryocytes, binucleated or multinucleated manifestations, and the nucleus of the cells is often deeply stained, and the chromatin is coarse and granular, and the distribution is not uniform. The nature of nuclear heterogeneous cells is between benign and malignant, and belongs to mesenchymal cells. Nuclear heterogeneous cells in pleural effusion may be caused by chronic inflammation of the lungs, lung cancer, chest wall tumors and other causes. Generally, the nuclear heterogeneity caused by inflammation is mild, and the nuclear heterogeneity caused by tumor cells is more severe; some of the nuclear heterogeneous cells will go on to develop into cancer cells, and should be alerted to the occurrence of malignant tumors in the lungs or chest. A small number of nuclear heterogeneous cells in pleural effusion should go to the hospital as soon as possible, complete the examination, clarify the cause of the disease, and carry out treatment under the guidance of the doctor.