**Core Concept**
In amyloidosis, abnormal fibrillar proteins (primarily amyloid A) deposit in tissues, disrupting normal function. In oral amyloidosis, especially of the tongue, deposition occurs in extracellular matrix components, with the stromal connective tissue being the most common site.

**Why the Correct Answer is Right**
Amyloid deposits in amyloidosis are extracellular, forming insoluble fibrils that accumulate in the **stromal connective tissue** of the tongue. These deposits are not intracellular or within epithelial cells. The stroma provides the structural framework where amyloid fibrils accumulate, leading to tissue stiffness and functional impairment. This pattern is characteristic of **systemic amyloidosis**, particularly type A (familial or secondary), and is observed in the submucosal layer of the tongue.

**Why Each Wrong Option is Incorrect**
Option B: The surface epithelium cells do not harbor amyloid deposits; amyloid is extracellular and not found in epithelial cell cytoplasm or nuclei.
Option C: Striated muscle cells are not involved in amyloid deposition in the tongue; muscle tissue is not a primary site.
Option D: Amyloid is not found in the cytoplasm of striated muscle cells; it is extracellular and does not infiltrate muscle cell interiors.

**Clinical Pearl / High-Yield Fact**
Amyloidosis of the tongue typically presents as a white, velvety, or nodular lesion, and the **stromal connective tissue** is the hallmark site of deposition. Always remember: **amyloid is extracellular**, not intracellular — this is a key diagnostic principle.

✓ Correct Answer: A. Stromal connective tissue