Neonatal paratesticular neuroblastoma misdiagnosed as in utero torsion of testis.

Reports of neuroectodermal primary scrotal tumors are scarce. Primary paratesticular neuroblastomas seem even rarer, and only five infants with this condition have been previously described. To the authors' knowledge, this would be the first report of a neonatal congenital paratesticular neuroblastoma. However, the authors postulate that ischemic compressive features in testis could lead to misdiagnosis as testicular torsion and the condition could usually go undetected. A newborn male baby with a left scrotal tumefaction was referred to the authors in May 2003. Doppler ultrasonography findings were inconclusive, and a diagnosis of intrauterine torsion of the testis was suspected. Surgery showed a paratesticular mass with a small attachment to an intra-abdominal epiploon. Pathologic examination clearly established the diagnosis of neuroblastoma. Cytogenetic findings (no amplification of N-myc oncogene, aneuploidy, and no deletion of chromosome 1p) were favorable. As the tumor was classified as International Neuroblastoma Staging System stage I, no additional chemotherapy was administered. All markers showed a progressive decrease, and herniorrhaphy and orchidopexy of the contralateral side were performed at 4 months of age. The patient was tumor-free at 11 months follow-up.