Isolated Sinusitis of Lateral Recesses of Sphenoid Sinus

Abstract

To the Editor: An 11-y-old boy presented with acute onset headache, eye pain and fever. There was no sinus tenderness, and symptoms did not resolve with oral antibiotics and antihistaminics. The CTscan of paranasal sinuses was done which revealed acute sinusitis with fluid only within lateral recesses of bilateral sphenoid sinuses (Fig. 1). This finding was also confirmed on MRI (Fig. 2). Rests of the sinuses, particularly bilateral frontal sinuses were clear (Fig. 3). No neurological complications were seen. The child was managed with intravenous antibiotics and endoscopic sphenoidotomy. Intraoperatively, hypertrophied inflamed polypoidal mucosa was seen involving the lateral recesses of sphenoid sinuses which were excised and curetted. On histopathological examination of the excised tissue, the lamina propria and epithelial layer showed extensive edema with infiltration of neutrophils and mononuclear cells, thrombophlebitis and necrotic foci suggestive of acute inflammatory pathology. Follow-up after one month showed near complete resolution with minimal soft tissue in right lateral recess (Fig. 4). Imaging finding of an isolated acute sinusitis of lateral recess of sphenoid sinus in a child is very uncommon and has not been described in the literature. The diagnosis is often delayed until there is a neurological complication. An important differential diagnoses with similar imaging findings that should be kept in mind while treating these cases is meningocele/meningoencephalocele of the lateral recesses, due to persistence of Sternberg’s canal. These patients usually present with spontaneous cerebrospinal fluid leaks and clinical meningitis. The anatomical location of Sternberg’s canal is medial to the superior orbital fissure Fig. 1 a Axial and b Coronal non-contrast CT scan of paranasal sinuses showing fluid within bilateral lateral recesses (arrow) of the sphenoid sinus (arrowhead) and clear bilateral ethmoid sinuses (asterisk)