Pediatric Horner syndrome and neuroblastoma threat.

T he article byJeffery et al. 1 on pages 159-67 of this issue of the Journal of AAPOS raises interesting points regarding pediatric Horner syndrome. On the basis of a retrospective review of 73 patients less than 18 years old seen over 10 years at two large referral centers, the authors provide a diagnostic paradigm emphasizing that seemingly idiopathic cases should be thoroughly investigated for the possible presence of malignancy, chiefly neuroblastoma. Their diagnostic workup would vary with the clinical profile and would include testing for urinary catecholamine breakdown products and imaging of the head, neck, chest, and abdomen. Generally, an ideal diagnostic paradigm is highly sensifive and specific for the particular clinical situation, safe, convenient, and cost effective. For pediatric Horner syndrome, the usual evaluation variably includes a physical examination, ophthalmologic examination, urinary assay for catecholamine breakdown products, and imaging studies. Thoughtful acquisition of data in each component of this workup can help make the overall diagnostic paradigm approach the ideal above. Underlying the fear of missing or delaying the diagnosis of neuroblastoma is the observation that the age at diagnosis is the most important prognostic factor, with children less than 1 year old having the best prognosis. Evidence now suggests that this is so, at least in part, because some of the tumors detected in early life are biologically more benign and some are perhaps destined to spontaneously involute without treatment. This may have been the case in cases 20 and 21 of the authors' report. Early diagnosis, although very desirable, may sometimes detect tumors destined for spontaneous involution, a lesson now well learned from the Japanese studies on mass screening for neuroblastoma. 2, 3 The physical evaluation should seek to exclude known causes of Homer syndrome and estimate the age of onset (inspection of old photographs is helpful). It should include palpation of the neck and abdomen for masses.