Cytology is the study in cells. In Medicine, Cytology is a branch of Pathology. It involves the analysis of cells from pap smear (cervical/vaginal samples), body fluids (such as from chest and abdominal cavities as well as urine, spinal fluid, sputum, etc.) and aspiration (samples removed by thin needle from various organs and parts of body, commonly lungs, liver, salivary glands, lymph nodes, etc.) Cytogenetics is the study of chromosomes of tumors, fetus/babies' tissue, amniotic fluid, normal tissue, etc.. Abnormal babies or placental tissue (hydatidiform mole) can have abnormal chromosomes (missing, extra, etc.). Tumors with abnormal number of chromosomes may behave more aggressively then ones with normal chromosome. Certain leukemia and lymphoma have characteristic abnormal patterns of their chromosomes. Cytogenetics can help diagnosing those neoplasia or cancer.