Cyst showing cholesterol crystals is/are:
**Core Concept**
The question is testing the student's ability to identify a characteristic feature of a specific type of cyst, which is essential in dermatology and pathology. Cholesterol crystals are a hallmark of a particular cystic lesion that forms due to the accumulation of keratin and cholesterol in the skin.
**Why the Correct Answer is Right**
The presence of cholesterol crystals is a key diagnostic feature of a steatocystoma, a benign skin cyst that occurs due to the abnormal keratinization of the skin. Steatocystomas are characterized by the accumulation of keratin and cholesterol, which eventually forms a cystic structure that can be identified by the presence of cholesterol crystals. The pathogenesis of steatocystoma involves the abnormal differentiation of keratinocytes, leading to the formation of a cystic structure that can be filled with keratin and cholesterol.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not mention the presence of cholesterol crystals, which is a key diagnostic feature of steatocystoma.
**Option B:** This option is incorrect because it refers to a different type of skin lesion, such as a sebaceous cyst, which does not typically contain cholesterol crystals.
**Option C:** This option is incorrect because it refers to a type of skin cancer, such as a basal cell carcinoma, which does not typically present with cholesterol crystals.
**Clinical Pearl / High-Yield Fact**
Steatocystoma is a benign skin cyst that can be identified by the presence of cholesterol crystals, which are formed due to the abnormal accumulation of keratin and cholesterol in the skin. This is an important clinical pearl to remember when diagnosing skin lesions.
**Correct Answer:** D. Steatocystoma