**Core Concept**
Leiomyoma, also known as uterine fibroids, are benign tumors arising from the smooth muscle layer of the uterus. These growths are hormone-dependent and influenced by estrogen and progesterone levels.

**Why the Correct Answer is Right**
Leiomyomas are characterized by increased cell proliferation, decreased apoptosis, and altered extracellular matrix composition. They often exhibit overexpression of estrogen and progesterone receptors, which contribute to their growth. However, leiomyomas typically do not exhibit increased **angiogenesis** (the formation of new blood vessels). This is in contrast to malignant tumors, which often induce angiogenesis to support their rapid growth.

**Why Each Wrong Option is Incorrect**
**Option A:**
*Increased cell proliferation* is a common feature of leiomyomas, leading to their growth and expansion.

**Option B:**
*Decreased apoptosis* (programmed cell death) is also characteristic of leiomyomas, allowing them to accumulate and grow.

**Option C:**
*Altered extracellular matrix composition* is indeed observed in leiomyomas, contributing to their growth and stiffness.

**Clinical Pearl / High-Yield Fact**
A key clinical correlation is that leiomyomas are more common in women with polycystic ovary syndrome (PCOS), possibly due to the hormonal influences on these growths.

**Correct Answer:** D.