Malignant ectomesenchymoma

Malignant ectomesenchymoma (MEM) is a rare, fast-growing tumor of the nervous system or soft tissue that occurs in children and young adults.

[4] The neuroectodermal component has the potential to display any neuroblastic tumor including neuroblastoma, ganglioneuroblastoma, and ganglion cells with or without schwannian stroma.

Mesenchymal elements, represented by rhabdomyosarcoma, were the dominant component in the majority of cases (5/6) while embryonal and alveolar morphology had equal distribution (3/6).

[8] Several translocations and genetic markers have been identified as possible oncogenic transformations in ectomesenchymoma: Treatment with chemotherapy led to a reduction in amplification of 6p21.32-p21.2 and 6p11.2 leading to rescue of HMGA1 and HMGA2 protein expression.

[12] The varied nature of these tumors sparked questions about the transformational factors which lead to cancerous expression across multiple mature cell types.

Because most of the effected population of ectomesenchymoma are juveniles, the long term carcinogenic and developmental risk of radiation therapy is fairly high.