Pediatric orbital solitary fibrous tumor/hemangiopericytoma presenting with isolated eyelid edema: a case report.

BACKGROUND: Orbital solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is an exceedingly rare mesenchymal neoplasm in the pediatric population. While typical orbital tumors present with proptosis or mass effect, the clinical picture can be deceptively indolent, leading to diagnostic delay. CASE PRESENTATION: A 15-year-old male patient presented with a 2-year history of progressive right upper eyelid edema that had repeatedly been misdiagnosed as conjunctivitis and visual fatigue. Notably, there was an absence of proptosis, visual decline, or ocular motility restriction. Magnetic resonance imaging revealed an extraconal mass posterior to the right globe. The patient underwent lateral orbitotomy with en bloc resection of a 4.5 cm × 3.5 cm × 2.5 cm dark-red, pseudocapsulated tumor. Histopathology and immunohistochemistry (CD34+, CD31-, S-100-, SMA-, and Ki-67 3%) confirmed the diagnosis of SFT/HPC. Given the tumor size and the potential risk of recurrence, adjuvant low-dose radiotherapy was administered after a multidisciplinary discussion. CONCLUSION: This case underscores that persistent, asymmetric eyelid edema in a child-even in the absence of classic orbital signs-warrants dedicated orbital imaging to exclude space-occupying lesions. Complete surgical resection via lateral orbitotomy provides the definitive diagnosis and effective local control for orbital SFT/HPC.