<prompt> Tumor containing cells of all three germ layers is called -LeiomyomaSquamous cell carcinomaAdenocarcinomaTeratoma  <response>: Ans. is d i.e., Teratoma o All Tumors, benign or malignant, have two basic components - Proliferative neoplastic cells -- constiture parenchymes. Suppoive stroma --- made up of connective tissue and blood vessels. o The name of tumor is usually based on the cell, e.g. smooth muscle cell tumor -- leiomyoma or leiomyosarcoma, skeletal muscle cell tumor rhabdomyosarcoma. o Benign tumors In general, benign tumors are designed by attaching the suffix - oma, e.g tumor of fibroblasts -- fibroma, tumor of cailagenous cells --- chondroma. o Malignant tumors Malignant tumors arising in mesenchymal cell origin are usually called sarcoma, e.g. fibrosarcoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma. Malignant tumors of epithelial cell origin are called carcinoma. Carcinoma may be fuher classified one with glandular growth pattern, i.e. adenocarcinoma and the other one producing recognizable squamous cells of epithelium, i.e. squamous cell carcinoma. o Germ layers and tumor Great majority of the neoplasm are composed of cells representative of a single germ layer. Teratomas, in contrast, are made up of a variety ofparenchymal cell types representative of more than one germ layer, usually all three. They arise from totipotent cells and so are principally encountered in the gonads. These totipotent cells differentiate along various germ lines, that can be identified as skin, fat, muscle, tooth structure, hair or any other tissue of the body. Example is dermoid cyst of ovary is a benign teratoma note -- mature teratoma is benign, while immature teratoma is malignant. Note-There are some exceptions to above general rules, i.e. malignant neoplasms with suffix - oma -- Melanomas, seminoma, hepatoma hepatocellular Ca, mesotheloma, lymphoma. 