A 16-year-old boy presents to the ENT clinic with a 6-month history of progressive unilateral nasal obstruction and recurrent epistaxis. His mother reports he has been experiencing postnasal drip and occasional otalgia. On examination, a smooth, reddish mass is visible in the nasopharynx, and there is blood-stained nasal discharge. Contrast-enhanced CT shows a highly vascular mass in the nasopharynx with widening of the pterygopalatine fossa and erosion of the pterygoid plates. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Nasopharyngeal Angiofibroma ### Key Clinical Features **Key Point:** Nasopharyngeal angiofibroma (NAF) is a benign but locally aggressive vascular tumor that presents classically in adolescent males (typically 10–25 years) with unilateral nasal obstruction and epistaxis. ### Diagnostic Criteria | Feature | Nasopharyngeal Angiofibroma | Clinical Significance | |---------|------------------------------|----------------------| | **Age of onset** | Adolescent males (10–25 yr) | Virtually pathognomonic age group | | **Chief complaint** | Unilateral nasal obstruction + epistaxis | Progressive, blood-stained discharge | | **Appearance** | Smooth, reddish, highly vascular mass | Nasopharyngeal location | | **Imaging hallmark** | Widening of pterygopalatine fossa, pterygoid plate erosion | Indicates locally aggressive growth | | **Vascularity** | Highly vascular on CT/MRI with contrast enhancement | Angiography shows feeding vessels | ### Pathophysiology & Origin 1. **Benign fibrovascular tumor** arising from the nasopharynx, typically near the sphenopalatine foramen 2. **Hormone-dependent growth** — testosterone-responsive, explaining male predominance and adolescent presentation 3. **Locally invasive** — erodes bone (pterygoid plates, clivus, sphenoid sinus) but does NOT metastasize 4. **Highly vascular** — fed by branches of the maxillary artery (sphenopalatine artery) ### Imaging Characteristics **High-Yield:** The **widening of the pterygopalatine fossa** and **pterygoid plate erosion** on CT are pathognomonic signs of NAF. MRI shows a mass with intermediate T1 signal and mixed T2 signal (due to vascularity and flow voids). ### Management Algorithm ```mermaid flowchart TD A[Suspected NAF on clinical grounds]:::outcome --> B[Confirm with CT/MRI]:::action B --> C{Extent of disease?}:::decision C -->|Small, localized| D[Endoscopic resection]:::action C -->|Large, extensive| E[Preoperative embolization]:::action E --> F[Endoscopic resection]:::action D --> G[Histopathology confirms diagnosis]:::outcome F --> G G --> H{Recurrence risk?}:::decision H -->|Low| I[Follow-up imaging at 6-12 months]:::action H -->|High| J[Consider adjuvant radiotherapy]:::action ``` ### Why This Diagnosis Fits **Clinical Pearl:** The combination of **adolescent male, unilateral epistaxis, nasopharyngeal mass, and CT findings of pterygoid plate erosion** is virtually diagnostic of NAF. No biopsy is needed preoperatively (risk of severe hemorrhage); diagnosis is confirmed on histology after resection. **Key Point:** NAF is the most common benign nasopharyngeal tumor in adolescents and young adults in the Indian population. ### Differential Exclusions - **Nasopharyngeal carcinoma:** Occurs in older adults (40–60 yr), associated with EBV and smoking; CT shows infiltrative mass without pterygoid widening. - **Antrochoanal polyp:** Unilateral but arises from maxillary sinus, not nasopharynx; non-vascular, no epistaxis. - **Rhabdomyosarcoma:** Rare in nasopharynx, occurs in younger children (<10 yr), more aggressive with systemic symptoms.