Orbital Apex Syndrome in a Patient With Histiocytic Sarcoma

Abstract

A man in his early 20s presented with a headache for 3 weeks and right ptosis and diplopia for 1 week as well as loss of vision in the right eye for 2 days. Neurological examination revealed an orbital apex syndrome including impairment of the right II, III, IV, V1, and VI cranial nerves. No significant personal or family history was present. Blood tests showed that his white blood cell count, erythrocyte sedimentation rate, C-reactive protein level, and procalcitonin level were all in normal ranges. Results of the serum galactomannan test and glucan test were negative. Lumbar puncture showed a normal white blood cell count, glucose level, and protein content in the cerebrospinal fluid. Results of india ink staining for Cryptococcus and Gram staining for bacteria in his cerebrospinal fluid were negative. Magnetic resonance imaging revealed a 2.4 × 2.8 × 3.6-cm mass lesion in the right ethmoid sinus and sphenoid sinus, with bone destruction of the inner wall of right orbit and involvement of the right medial rectus muscle and right optic nerve. The mass appeared isointense and hyperintense to muscle on T1-weighted and T2-weighted images, with heterogeneous enhancement on postcontrast T1-weighted images (Figure 1). Surgical removal of the mass was performed.Microscopically, the lesion was composed of atypical tumor cells with oval nucleus, small nucleolus, eosinophilic cytoplasm, and scattered mitotic figures. Immunohistochemical stainings showed the tumor cells were positive for vimentin,