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 having difficulty breathing through the left nostril and occasional blood-stained nasal discharge. On examination, a smooth, reddish mass is visible in the left nasal cavity. Nasal endoscopy reveals a highly vascular mass originating from the sphenoid rostrum. CT scan shows a lobulated mass with mixed density and widening of the pterygopalatine fossa. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Nasopharyngeal Angiofibroma ### Key Clinical Features **Key Point:** Nasopharyngeal angiofibroma (NAF) is a benign, highly vascular tumor that presents classically in adolescent males with unilateral nasal obstruction and epistaxis. ### Diagnostic Hallmarks | Feature | Nasopharyngeal Angiofibroma | Clinical Significance | |---------|---------------------------|----------------------| | **Age of presentation** | 10–25 years (peak 15–20 years) | Almost exclusively adolescent males | | **Sex predilection** | Male : Female = 4:1 | Androgen-dependent growth | | **Chief complaint** | Unilateral nasal obstruction (80%) | Epistaxis (60%), blood-stained discharge | | **Site of origin** | Sphenoid rostrum / pterygopalatine fossa | Arises from nasopharyngeal roof near sphenoid | | **Appearance** | Smooth, reddish, highly vascular mass | Non-ulcerated, non-necrotic | | **Imaging hallmark** | Widening of pterygopalatine fossa on CT | Characteristic "bowing" of posterior maxilla | | **Angiography finding** | Intense homogeneous blush | Supplied by branches of maxillary artery | ### Why This Case Fits NAF 1. **Age & sex:** 16-year-old boy (classic demographic) 2. **Unilateral presentation:** Typically one-sided nasal obstruction 3. **Epistaxis:** Hallmark symptom due to extreme vascularity 4. **Endoscopic appearance:** Smooth, reddish, highly vascular mass 5. **Imaging findings:** Mass at sphenoid rostrum with widening of pterygopalatine fossa — pathognomonic **High-Yield:** The combination of adolescent male + unilateral epistaxis + mass at sphenoid rostrum = NAF until proven otherwise. ### Pathophysiology **Clinical Pearl:** NAF is a benign mesenchymal tumor with fibrous and angiomatous components. It is NOT malignant but is locally aggressive and highly vascular, making it prone to severe hemorrhage. Growth is androgen-dependent; tumors may regress after puberty or with hormonal therapy. ### Staging (Fisch Classification) - **Stage I:** Tumor limited to nasopharynx and nasal cavity - **Stage II:** Tumor extends into pterygopalatine fossa ± maxillary/ethmoid sinuses - **Stage III:** Tumor extends into infratemporal fossa, orbit, or skull base - **Stage IV:** Intracranial extension This case is **Stage II** (pterygopalatine fossa involvement on imaging). ### Management Algorithm ```mermaid flowchart TD A[Suspected NAF]:::outcome --> B[Confirm with CT/MRI + Angiography]:::action B --> C{Staging}:::decision C -->|Stage I-II| D[Preoperative embolization]:::action D --> E[Endoscopic resection]:::action C -->|Stage III-IV| F[Consider open approach ± multimodal therapy]:::action E --> G[Monitor for recurrence]:::outcome F --> G ``` **Key Point:** Preoperative embolization is mandatory to reduce intraoperative hemorrhage. ### Why NAF and Not Other Diagnoses - ~~Squamous cell carcinoma~~ — occurs in older adults, ulcerated, not as vascular - ~~Olfactory neuroblastoma~~ — arises from cribriform plate, different age group, less epistaxis - ~~Inverted papilloma~~ — unilateral but typically in older patients, less vascular, different imaging [cite:Robbins 10e Ch 16]