Congenital or acquired Horner's?

Dear Editor,

It has been estimated that less than 5% of Horner′s syndrome (HS) are congenital in the pediatric population.1 Jeffery et al . conducted a case series of 31 pediatric patients with HS and reported that 42% were congenital, 15% were acquired without surgical intervention and 42% were after a surgical procedure of the thorax, neck or central nervous system.2

A seven-month-old female baby presented to us with mild ptosis and an apparent enophthalmos (2 mm) of the right eye and right hemifacial anhidrosis. She was born full-term normal vaginal delivery.

On examination she had subtle anisocoria of approximately 2mm with a right mitotic pupil, (pupil lag+) and brown colored iris in both eyes [Fig. 1]. She could follow light in all directions with each eye individually. Abdominal examination by pediatrician was normal.

Figure 1

Seven-month-old female baby with miosis, apparent enophthalmos of right eye and anhidrosis of right side of face

A provisional diagnosis of HS was made and the same was confirmed by instillation of topical 0.5% apraclonidine eye drop which showed complete elimination of ptosis in the right eye and dilatation of the pupil. Further investigations were done to identify a possible cause for Horner′s syndrome. X-ray chest posterior-anterior view showed no mass in the thorax. Magnetic resonance imaging (MRI) of the neck showed a heterogeneously enhancing soft tissue lesion involving the root of neck that measured 2.26 x 1.80 cm [Fig. 2]. The lesion was located close to or arising from the right sympathetic chain, which could have been either a lymph node or paraganglioma. The MRI of the thorax and abdomen was normal. Urine vanillylmandelic acid (VMA) assay yielded normal results excluding the possibility of neuroblastoma (32 micro moles/24h of urine) although there are varied reports on the reliability on this test since elevation of urine catecholamine mainly depends on tumor bulk.3 It was opined in consultation with the neurosurgeon to observe the progression and avoid biopsy since the lesion was very close to major vessel and had a high chance of hemorrhage.

Figure 2

MRI of the neck showing a heterogeneously enhancing soft tissue lesion involving the root of neck

Though brachial plexus injury is the most common cause of congenital HS, any lesion along the sympathetic chain may result in HS. Among these lesions, timely diagnosis of primary thoracic or cervical neuroblastoma is very crucial.2,4,5

In our case, the presence of anhidrosis indicated preganglionic lesion and MRI showed a mass along the second order neuron between the ciliospinal center of Budge and Waller and the superior cervical ganglion. Based on radiographic characteristics, the lesion was thought to be either an enlarged lymph node or a paraganglioma. Lymphadenopathy is an unlikely cause for this presentation, as there was no infectious or inflammatory lesion within the draining area of the cervical lymph node in the neck. Normal urinary VMA ruled out neuroblastoma, leaving us with the most probable diagnosis of the mass being nonchromaffin paraganglioma. Nonchromaffin paraganglioma is predominantly a benign tumor arising from paraganglionic cells anywhere in the body. They occur most commonly in the retroperitoneum or head and neck region and are usually not suspected at the time of presentation,6 due to their nonspecific nature of presentation.

Although delivery-related brachial plexus injury is the most common cause of congenital HS, from our case we feel it is important to do imaging of the entire sympathetic pathway, since life-threatening malignancy and abnormalities may be revealed.