## **Core Concept**
Leiomyosarcoma is a type of malignant smooth muscle tumor. It can occur in any part of the body where smooth muscle is present, such as the uterus, gastrointestinal tract, and soft tissues. The age distribution of leiomyosarcoma varies depending on the site of origin.

## **Why the Correct Answer is Right**
Leiomyosarcomas are more common in adults, particularly in the fifth to seventh decades of life. The peak age incidence is often reported to be around 50-60 years. This tumor type is relatively rare and can arise in various locations, but its occurrence is indeed more frequent in older adults.

## **Why Each Wrong Option is Incorrect**
* **Option A:** This option suggests a younger age group, which is not typical for the peak incidence of leiomyosarcoma.
* **Option B:** While leiomyosarcomas can occur in a wide age range, this option does not accurately represent the most common age group.
* **Option D:** This option suggests an even older age group than the correct answer, which, although possible, is not the most common age range for leiomyosarcoma occurrence.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that leiomyosarcomas are rare and can be challenging to diagnose. They are often considered in the differential diagnosis of a palpable abdominal mass or uterine tumor in adults, particularly in the 50-60 age group.

## **Correct Answer:** C. 50-60 years.