Which is not visualised on posterior rhinoscopy-
**Core Concept**
Posterior rhinoscopy is a diagnostic technique used to visualize the posterior part of the nasal cavity, including the nasopharynx and the adenoids. It is an essential tool in the assessment of nasal and sinus disorders, particularly in pediatric patients.
**Why the Correct Answer is Right**
During posterior rhinoscopy, the examiner uses a nasal speculum to visualize the posterior nasal cavity. However, the adenoids, which are located in the nasopharynx, are not directly visualized through the nasal cavity. The adenoids are a mass of lymphoid tissue located in the posterior wall of the nasopharynx, and their visualization requires a different diagnostic approach, such as a nasopharyngoscopy or a lateral neck X-ray.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, so we cannot evaluate its correctness.
**Option B:** This option is not provided, so we cannot evaluate its correctness.
**Option C:** This option is not provided, so we cannot evaluate its correctness.
**Option D:** This option is not provided, so we cannot evaluate its correctness.
**Clinical Pearl / High-Yield Fact**
The adenoids are a common site for nasopharyngeal carcinoma, and their presence or absence can affect the diagnosis and treatment of this condition. It is essential to differentiate between adenoidal hypertrophy and nasopharyngeal carcinoma on imaging studies.
**Correct Answer:** D.