Unusual location of sinonasal ossifying fibroma of the posterior ethmoid sinus: a case report and literature review.

INTRODUCTION AND

IMPORTANCE

Ossifying fibroma is a benign, well-demarcated fibro-osseous neoplasm that most commonly affects the mandible and maxilla. Involvement of the paranasal sinuses is rare, and ethmoid sinus localization is particularly uncommon. Because sinonasal ossifying fibroma may mimic other fibro-osseous and osseous lesions radiologically, histopathologic confirmation and complete excision are important for diagnosis and disease control.

CASE PRESENTATION: A 43-year-old Saudi man with well-controlled type 2 diabetes mellitus presented with a 6-month history of progressive right-sided nasal obstruction and frontal headache. He reported no history of epistaxis, visual disturbance, or anosmia. Computed tomography demonstrated a well-defined 2.5 × 1.6 × 2.3 cm sclerotic lesion with ground-glass matrix occupying the right posterior ethmoid air cells and abutting the skull base. Histopathology confirmed ossifying fibroma. The patient underwent complete endoscopic transnasal resection with skull base repair using a free autologous cartilage graft. The clinical course is summarized in Table 1. Recovery was uneventful, and he was discharged on postoperative day two.

CLINICAL DISCUSSION: Ethmoidal ossifying fibroma is rare and may present with nonspecific sinonasal symptoms. Complete excision is recommended for symptomatic sinonasal disease because incomplete removal is associated with recurrence. In selected cases, an endoscopic approach can provide direct visualization, avoid external approach-related morbidity, and allow skull base reconstruction when required. However, 4-month follow-up is insufficient to make definitive statements about long-term recurrence.

CONCLUSION

Posterior ethmoid ossifying fibroma is an uncommon presentation of a benign fibro-osseous tumor. Accurate diagnosis requires clinical, radiologic, and histopathologic correlation. Complete endoscopic resection with appropriate skull base repair can achieve favorable short-term outcomes in selected cases, but prolonged surveillance is necessary.