Catecholamine metabolites in ganglioneuroma

With rare exception, ganglioneuroma (GN) is a benign lesion which presents as a localized mass without metastatic potential and which is chemotherapy resistant. Thus, its distinction from neuroblastoma (NB) may be important. The diagnosis of GN implies the absence of neuroblastic elements. Incomplete resection prevents complete microscopic examination and raises the possibility that focal NB was not sampled. In an attempt to determine what features other than histology distinguish these two entities, we reviewed the charts of 25 patients with GN with regard to patient age and sex, tumor location and size, and urine catecholamine metabolite levels. One patient with GN (5%) and gross total resection had elevated quantitative vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels (2.4 x upper limit of normal for age), and two others had positive spot analyses for VMA. An additional patient with a large mass, multiple biopsies of which documented GN, also had greatly elevated (approximately 5 x normal) VMA and HVA levels. However, a subsequent attempt at resection disclosed several gross foci of NB. Even excluding this patient, there was a trend for elevated values in GN patients to correlate with tumor size (P = .07 and .14 for VMA and HVA, respectively). The incidence of elevated values appears to increase as a function of tumor size, and small tumors are not likely to result in positive urinary measurements. We conclude that while elevations of VMA and HVA are consistent with a well-documented diagnosis of GN, extreme elevations (> 3 x nl) should prompt careful serial evaluation for occult NB.