**Core Concept**
Depapillation of the tongue, also known as atrophy of the lingual papillae, refers to the thinning or loss of the small projections on the surface of the tongue. This can be caused by various conditions that affect the tongue's innervation, nutrition, or overall health. In the context of pathology, depapillation can be a sign of underlying systemic or local disease processes.

**Why the Correct Answer is Right**
Amyloidosis is a condition characterized by the deposition of abnormal proteins (amyloid) in various tissues and organs. While amyloidosis can affect the tongue, it typically leads to macroglossia (enlargement of the tongue) and not depapillation. The correct answer is B. Amyloidosis because amyloid deposits in the tongue are more likely to cause thickening and swelling rather than thinning or loss of papillae.

**Why Each Wrong Option is Incorrect**
**Option A:** Plummer-Vinson syndrome is a rare condition characterized by dysphagia, iron-deficiency anemia, and esophageal webs. It can lead to depapillation of the tongue due to iron deficiency and chronic inflammation.

**Option C:** Pernicious anemia is a type of megaloblastic anemia caused by a deficiency of vitamin B12. It can lead to depapillation of the tongue due to the loss of lingual papillae and atrophy of the tongue.

**Option D:** Luetic glossitis is a condition caused by syphilis infection, leading to inflammation and depapillation of the tongue.

**Clinical Pearl / High-Yield Fact**
Depapillation of the tongue can be a sign of underlying systemic conditions, including iron-deficiency anemia, vitamin B12 deficiency, and chronic inflammation. It is essential to investigate the underlying cause of depapillation to provide appropriate treatment and management.

**✓ Correct Answer: B. Amyloidosis**