Ethmoidal sinus mucocele: an unusual cause of acquired Brown syndrome
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《英国眼科学杂志》
Jules Stein Eye Institute, University of California Los Angeles, CA, USA
Correspondence to:
Arthur L Rosenbaum
MD, Jules Stein Eye Institute, 100 Stein Plaza, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7002, USA; rosenbaum@jsei.ucla.edu
Accepted for publication 20 December 2004
Keywords: Brown syndrome; mucocele; superior oblique tendon sheath
Brown syndrome was first characterised in 1950 by Harold Whaley Brown as a restrictive limitation to elevation in adduction.1 On the basis of surgical findings Brown implicated a shortened superior oblique (SO) tendon sheath as the cause of this syndrome. Most subsequent reports have alternatively proposed an abnormality in the trochlear-SO tendon complex as the cause of restriction to elevation in adduction. Although various causes of acquired Brown syndrome have been described, its association with ethmoidal mucocele is very rare.
Case report
A 38 year old man noted sudden onset of binocular vertical diplopia appreciable in levoversion and relieved with chin-up position. There was no history of trauma or any medical illness.
Uncorrected visual acuity was 20/20 in both eyes. A soft compressible tender mass measuring 2x2 cm on the superonasal aspect of the right upper lid extending from the trochlea to the medial canthal tendon was noted. Motility examination showed underelevation in adduction of the right eye mimicking Brown syndrome (fig 1). A right hypotropia of 2 in primary gaze increasing to 4 in left and upgaze was present.
Figure 1 Preoperative versions of subject in nine diagnostic positions of gaze, demonstrating underelevation on adduction of the right eye.
Contrast magnetic resonance imaging (MRI) (fig 2) revealed an expansile non-enhancing 3–4 cm mass of the right ethmoidal sinus having an intraorbital extraconal extension consistent with a mucocele. The mass appeared to be pressing on the globe causing effacement of the right medial rectus and superior oblique tendon with anterolateral displacement of the trochlea. Endoscopic removal of the mass with subsequent pathology confirmed the diagnosis of mucocele. Following endoscopic removal the patient was asymptomatic for diplopia. Upgaze ability in adduction was improved, but still moderately limited.
Figure 2 Orbital contrast MRI showing non-enhancing 3–4 cm mass of the right ethmoidal sinus having an intraorbital extraconal extension.
Comment
Various aetiologies of acquired Brown syndrome have been described such as frontal sinus surgery,2 blepharoplasty,3 chronic sinusitis, trauma, inflammatory,4 systemic lupus erythematosis,5 and restrictive fibrous bands. An isolated case of acquired Brown syndrome caused by a fronto-ethmoidal mucocele has been reported.6 High resolution MRI demonstrated varied abnormalities in both congenital and acquired Brown syndrome such as traumatic or iatrogenic scarring, avulsion of the trochlea, cyst in the superior oblique tendon, inferior displacement of the lateral rectus pulley, and fibrous restrictive bands extending from the trochlea to the globe.7
According to the anatomic abnormalities noted by MRI, four distinct mechanisms of Brown syndrome were identified: trochlear damage, SO tendon abnormalities, abnormalities of rectus extraocular muscle pulleys, and congenital abnormalities of SO muscle.7 MRI can define the pathological anatomical abnormalities causing Brown syndrome, thereby individualising surgical management without reliance on extensive exploratory surgery.
References
Brown HW. Congenital structural muscle anomalies. In: Allen JH, ed. Strabismus ophthalmic symposium. St Louis: CV Mosby, 1950:205–36.
Rosenbuam AL, Astle WF. Superior oblique and inferior rectus muscle injury following frontal and intranasal sinus surgery. J Pediatr Ophthalmol Strabismus 1985;22:194–202.
Levine MR, Boynton J, Tenzel RR, et al. Complications of blepheroplasty. Ophthalmic Surg 1975;6:47–53.
Hermann JS. Acquired Brown’s syndrome of inflammatory origin. Arch Ophthalmol 1978;96:1228–32.
Whitefield L, Isenberg DA, Brazier DJ, et al. Acquired Brown’s syndrome in systemic lupus erythematosus. Br J Rheum 1995;34:1092–4.
Lacy PD, Rhatigan M, Colreavy MP, et al. Acquired Brown’s syndrome caused by a fronto-ethmoidal mucocele. Aust N Z J Surg 2000;70:688–9.
Demer JL, Bhola R, Ortube MC, et al. High resolution magnetic resonance imaging demonstrates varied anatomic abnormalities in Brown’s syndrome. In: Abstracts of the Annual Meeting of the American Association of Pediatric Ophthalmology and Strabismus, 27–31 March 2004. Washington DC, Paper 15.(R Bhola and A L Rosenbaum)
Correspondence to:
Arthur L Rosenbaum
MD, Jules Stein Eye Institute, 100 Stein Plaza, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7002, USA; rosenbaum@jsei.ucla.edu
Accepted for publication 20 December 2004
Keywords: Brown syndrome; mucocele; superior oblique tendon sheath
Brown syndrome was first characterised in 1950 by Harold Whaley Brown as a restrictive limitation to elevation in adduction.1 On the basis of surgical findings Brown implicated a shortened superior oblique (SO) tendon sheath as the cause of this syndrome. Most subsequent reports have alternatively proposed an abnormality in the trochlear-SO tendon complex as the cause of restriction to elevation in adduction. Although various causes of acquired Brown syndrome have been described, its association with ethmoidal mucocele is very rare.
Case report
A 38 year old man noted sudden onset of binocular vertical diplopia appreciable in levoversion and relieved with chin-up position. There was no history of trauma or any medical illness.
Uncorrected visual acuity was 20/20 in both eyes. A soft compressible tender mass measuring 2x2 cm on the superonasal aspect of the right upper lid extending from the trochlea to the medial canthal tendon was noted. Motility examination showed underelevation in adduction of the right eye mimicking Brown syndrome (fig 1). A right hypotropia of 2 in primary gaze increasing to 4 in left and upgaze was present.
Figure 1 Preoperative versions of subject in nine diagnostic positions of gaze, demonstrating underelevation on adduction of the right eye.
Contrast magnetic resonance imaging (MRI) (fig 2) revealed an expansile non-enhancing 3–4 cm mass of the right ethmoidal sinus having an intraorbital extraconal extension consistent with a mucocele. The mass appeared to be pressing on the globe causing effacement of the right medial rectus and superior oblique tendon with anterolateral displacement of the trochlea. Endoscopic removal of the mass with subsequent pathology confirmed the diagnosis of mucocele. Following endoscopic removal the patient was asymptomatic for diplopia. Upgaze ability in adduction was improved, but still moderately limited.
Figure 2 Orbital contrast MRI showing non-enhancing 3–4 cm mass of the right ethmoidal sinus having an intraorbital extraconal extension.
Comment
Various aetiologies of acquired Brown syndrome have been described such as frontal sinus surgery,2 blepharoplasty,3 chronic sinusitis, trauma, inflammatory,4 systemic lupus erythematosis,5 and restrictive fibrous bands. An isolated case of acquired Brown syndrome caused by a fronto-ethmoidal mucocele has been reported.6 High resolution MRI demonstrated varied abnormalities in both congenital and acquired Brown syndrome such as traumatic or iatrogenic scarring, avulsion of the trochlea, cyst in the superior oblique tendon, inferior displacement of the lateral rectus pulley, and fibrous restrictive bands extending from the trochlea to the globe.7
According to the anatomic abnormalities noted by MRI, four distinct mechanisms of Brown syndrome were identified: trochlear damage, SO tendon abnormalities, abnormalities of rectus extraocular muscle pulleys, and congenital abnormalities of SO muscle.7 MRI can define the pathological anatomical abnormalities causing Brown syndrome, thereby individualising surgical management without reliance on extensive exploratory surgery.
References
Brown HW. Congenital structural muscle anomalies. In: Allen JH, ed. Strabismus ophthalmic symposium. St Louis: CV Mosby, 1950:205–36.
Rosenbuam AL, Astle WF. Superior oblique and inferior rectus muscle injury following frontal and intranasal sinus surgery. J Pediatr Ophthalmol Strabismus 1985;22:194–202.
Levine MR, Boynton J, Tenzel RR, et al. Complications of blepheroplasty. Ophthalmic Surg 1975;6:47–53.
Hermann JS. Acquired Brown’s syndrome of inflammatory origin. Arch Ophthalmol 1978;96:1228–32.
Whitefield L, Isenberg DA, Brazier DJ, et al. Acquired Brown’s syndrome in systemic lupus erythematosus. Br J Rheum 1995;34:1092–4.
Lacy PD, Rhatigan M, Colreavy MP, et al. Acquired Brown’s syndrome caused by a fronto-ethmoidal mucocele. Aust N Z J Surg 2000;70:688–9.
Demer JL, Bhola R, Ortube MC, et al. High resolution magnetic resonance imaging demonstrates varied anatomic abnormalities in Brown’s syndrome. In: Abstracts of the Annual Meeting of the American Association of Pediatric Ophthalmology and Strabismus, 27–31 March 2004. Washington DC, Paper 15.(R Bhola and A L Rosenbaum)