A benign or malignant tissue growth resulting from uncontrolled cell proliferation. Benign neoplastic cells resemble normal cells without exhibiting significant cytologic atypia, while malignant cells exhibit overt signs such as dysplastic features, atypical mitotic figures, necrosis, nuclear pleomorphism, and anaplasia. Representative examples of benign neoplasms include papillomas, cystadenomas, and lipomas; malignant neoplasms include carcinomas, sarcomas, lymphomas, and leukemias. [ NCIT:C3262 ]