Rhabdomyosarcoma arising from a dormant dumbbell ganglioneuroma of the lumbar spine: a case report.

Study Design: A case report of a lumbar dumbbell tumor that showed a sequential change in histology from ganglioneuroma into rhabdomyosarcoma after long-term dormancy.

Objective: To present a case of non-neurogenic malignancy arising from ganglioneuroma.

Summary Of Background Data: Ganglioneuromas rarely form the dumbbell variety. Whereas conversion of ganglioneuroma into neurogenic malignancies occurs occasionally, between ganglioneuroma and mesenchymal malignancies it has so far been limited to a case in which ganglioneuroma developed after chemo- and radiotherapy for orbital rhabdomyosarcoma.

Methods: A 61-year-old man was referred with a recurrent retroperitoneal tumor that had been excised as ganglioneuroma. Using imaging, histologic, and immunohistochemical studies, a comparative analysis of the primary and recurrent tumors was performed.

Results: A total of 44 histologic sections were examined for the primary and the recurrent tumors that had been excised surgically, with an 8-month interval between resections. Histologic and immunohistochemical findings in the primary tumor were consistent with ganglioneuroma, whereas those in the recurrent tumor indicated rhabdomyosarcoma.

Conclusions: It is assumed that the rhabdomyosarcoma arose from a dumbbell ganglioneuroma as a component of malignant ectomesenchymoma.