A case of ecchordosis physaliphora presenting with an abducens nerve palsy: A rare symptomatic case managed with endoscopic endonasal transsphenoidal surgery
A 20-year-old healthy male was admitted to our hospital for sudden onset of diplopia. Physical examination at admission revealed right abducens nerve palsy but no other neurological disorder. The diplopia arose when he gazed straight ahead or to the right. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a lesion, measuring 22 mm in diameter, which was isodense and had no enhancement on CT. On MRI, the lesion appeared heterogeneously hyperintense on a T1-weighted image, more hyperintense on a T2-weighted image, and had slightly restricted diffusion on diffusion-weighted images. No contrast enhancement was observed after the addition of gadolinium diethylenetriamine pentaacetic acid. The lesion compressed the patient's pons and right abducens nerve [].\nETSS was performed. A gelatinous mass was partially exposed after removing the mucosa of the sphenoid sinus. The clival bone was drilled to entirely expose the mass, which was mainly located in the extradural space and partially located intradurally, accompanied by a small dural defect. The intradural mass had compressed the arachnoid mater, which had a yellowish discoloration []. To avoid damage to the patient's right abducens nerve, the mass in Dorello's canal was partially removed. A waterproof repair of the clivus was performed to avoid cerebrospinal fluid (CSF) leakage using Surgicel® (Ethicon 360, Menlo Park, CA, USA) with fibrinogen and Spongel® (Ethicon 360) with thrombin followed by formation of a pediculate septomucosal flap.\nThe patient's postoperative course was uneventful. Postoperatively, the right abducens nerve palsy improved, but his diplopia persisted when he gazed to the right. Postoperative MRI demonstrated partial removal of the mass, adequate for decompression []. Four months postoperatively, the patient's right abducens nerve palsy and diplopia completely resolved. No residual mass was revealed on MRI []. At 1-year follow-up, the patient remained symptom- and disease-free.\nPathological examination of the mass showed hypocellular physaliphorous cells with a lobular growth pattern and eosinophilic cytoplasm with vacuolated mucous droplets. Neither mitosis nor dyskaryosis were visible []. Immunohistochemical study showed positive with antibodies against Cytokeratins. The Ki-67 (MIB-1) index, evaluated using the MIB-1 antigen against Ki-67, was not increased. The MRI findings, pathological aspects, clinical course, and surgical findings suggested EP.