Ectopic neuroblastoma of the thoracic wall: a case report.

A case of thoracic neuroblastoma arising at the anterior mammillary line from the inner surface of the second and third right rib in a 17-month-old male child is reported. Primary surgery allowed excision of the mass. According to the histologic, histochemical, and molecular features of the tumor, all consistent with the diagnosis of neuroblastoma stage 2, the patient underwent adjuvant chemotherapy and, after 2 years, he is alive and disease free at follow-up. In view of different clinical and therapeutical approaches, only a strict adherence to histopathologic criteria allows differentiation of neuroblastoma, even in a very unusual anatomical site, from other small-cell, peripheral neoplasms presumably arising from the embryonic neural crest, such as Askin's tumor, neuroepithelioma, and ectomesenchymoma. The site of origin of these tumors is an important diagnostic clue but can be misleading: only careful microscopic evaluation and molecular analysis lead to incontrovertible diagnosis and yield correct clinical management.