Where is conjunctival lymphoid tissue considered abnormal?

Conjunctival lymphoid tissue serves an important role in the ocular immune response. In healthy individuals, it is normally present in certain areas of the conjunctiva and its appearance can vary based on the location.

When assessing lymphoid tissue in the conjunctiva, it is considered abnormal when found in locations not typically associated with lymphoid aggregation. The bulbar surface (the portion of the conjunctiva covering the eyeball) is generally not a site where lymphoid follicles are expected. The presence of lymphoid tissue in this area indicates a pathologic condition, often linked to chronic irritation or inflammation, as lymphoid tissue is usually concentrated in areas where there is a high demand for immune surveillance, such as the palpebral conjunctiva and third eyelid.

Thus, lymphoid tissue appearing in any location other than the bulbar surface—such as within the palpebral conjunctiva or the third eyelid—is expected and not deemed abnormal. Consequently, the identification of lymphoid tissue on the bulbar surface as abnormal supports the interpretation that this tissue is inappropriately located, which is why this option is considered correct.