Certified Tumor Registrar (CTR) Practice Exam

What is a neoplasm of smooth muscle origin?

1. Rhabdomyosarcoma

2. Leiomyosarcoma

3. Osteosarcoma

4. Hemangioma

The correct answer is: Leiomyosarcoma

A neoplasm of smooth muscle origin is defined as a tumor that develops from smooth muscle tissue, which is the type of muscle found in various internal structures, such as blood vessels and the gastrointestinal tract. Leiomyosarcoma is a type of malignant tumor that specifically arises from smooth muscle cells. It is characterized by the uncontrolled growth of smooth muscle tissue and is known for its more aggressive behavior compared to benign smooth muscle tumors. The other options represent different types of tissues or muscle origins. Rhabdomyosarcoma, for example, arises from striated (skeletal) muscle, not smooth muscle. Osteosarcoma originates from bone tissue, and hemangioma is a benign neoplasm comprised of blood vessels. Therefore, the distinctive origin of leiomyosarcoma from smooth muscle clearly designates it as the correct answer regarding neoplasms associated with smooth muscle.