Abstract
INTRODUCTION AND IMPORTANCE: Nasopharyngeal carcinoma (NPC) is an epithelial malignancy of the nasopharyngeal mucosa, most often arising in the fossa of Rosenmüller. While exceedingly rare in children under 10 years, it shows a male predominance. CASE PRESENTATION: A 9-year-old male presented with bilateral cervical lymphadenopathy persisting for 1 year. Initially, unilateral right-sided neck swelling progressed to bilateral involvement with a left-sided mass. Trucut biopsy showed features consistent with Kimura disease. Repeat ultrasound-guided lymph node biopsy revealed an Epstein-Barr virus (EBV)-positive non-keratinizing metastatic carcinoma, suggestive of NPC, further confirmed by immunohistochemical analysis. Treatment with neoadjuvant platinum-based chemotherapy, followed by radiotherapy, achieved a complete clinical response at 6 months. CLINICAL DISCUSSION: This case demonstrates a critical diagnostic pitfall where pediatric NPC initially masqueraded as Kimura disease due to inflammatory-predominant tissue sampling. The diagnostic breakthrough came through repeat ultrasound-guided biopsy with comprehensive immunohistochemical analysis and EBV-encoded RNA in situ hybridization, confirming EBV-positive non-keratinizing NPC. Multimodal imaging (CT/MRI/PET) established T2N3M0 staging. After neoadjuvant platinum-based chemotherapy followed by conformal radiotherapy, a complete clinical response at 6 months was achieved. In resource-limited settings, prioritizing repeat targeted biopsy, tissue-based EBV detection, and conformal radiotherapy offers an effective diagnostic and therapeutic pathway for this rare but treatable childhood malignancy. CONCLUSION: In a resource-limited setting like Nepal, for the early diagnosis and treatment of NPC, a combination of novel testing methods and a high index of suspicion in a patient with unilateral or bilateral neck swelling is necessary.