**Core Concept**
Epiphyseal dysgenesis refers to the abnormal development or formation of the epiphysis, which is the end part of a long bone that is initially separate from the main bone shaft (diaphysis) but eventually fuses with it during growth and development. This condition can result in various skeletal abnormalities.

**Why the Correct Answer is Right**
The condition that shows epiphyseal dysgenesis as a pathognomonic feature is **Pyle's disease**. Pyle's disease is a rare disorder characterized by the abnormal growth of the epiphyses, leading to their enlargement and subsequent fusion with the metaphysis. This results in the characteristic radiographic appearance of "cupped" epiphyses. The pathogenesis of Pyle's disease is thought to involve a defect in the growth plate, leading to an abnormality in the formation of the epiphysis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because **achondroplasia** is a genetic disorder that affects bone growth, but it does not primarily manifest as epiphyseal dysgenesis.

**Option B:** This option is incorrect because **osteogenesis imperfecta** is a genetic disorder that affects the production of collagen, leading to brittle bones, but it does not specifically involve epiphyseal dysgenesis.

**Option C:** This option is incorrect because **multiple epiphyseal dysplasia** is a condition that affects the development of the epiphyses, but it is not a pathognomonic feature of a specific disease.

**Clinical Pearl / High-Yield Fact**
Pyle's disease is a rare condition that should be considered in the differential diagnosis of skeletal abnormalities, particularly when radiographic findings suggest epiphyseal dysgenesis.

**Correct Answer:** D.