Orbital Pseudocellulitis: A Retinoblastoma-Associated Masquerade Syndrome.

Introduction: A masquerade syndrome is an atypical presentation of a neoplastic process that mimics an inflammatory condition. In this paper, we focus on orbital pseudocellulitis.

Case Series: Our case series includes 5 retinoblastoma patients with orbital pseudocellulitis at presentation. In 3 patients the disease was bilateral, in 1 trilateral, and in 1 unilateral. The eyes with pseudocellulitis were enucleated, while the fellow eyes were treated conservatively, when affected. Four patients responded well to the therapy and showed remission of the tumor. The patient with trilateral retinoblastoma did not respond to therapy and died of disease.

Discussion: Differential diagnosis with infectious orbital cellulitis is extremely important. Patients with orbital cellulitis present with fever, sinusitis, leukocytosis, and raised inflammatory markers, while ophthalmoscopic examination is negative and imaging studies show sinus involvement. On the contrary, patients with retinoblastoma do not show systemic inflammation, while ophthalmoscopic examination reveals leukocoria, buphthalmos, and an intraocular tumor mass associated with retinal detachment. Magnetic resonance imaging shows intralesional calcifications and soft tissue edema without sinus involvement. Histology confirms the diagnosis.

Conclusions: Medical history, physical examination, and imaging studies are crucial in the diagnosis of retinoblastoma-associated orbital pseudocellulitis. Retinoblastoma should be excluded in all patients with signs of pre-septal orbital cellulitis through fundoscopy and/or imaging studies.