A distinctive epitheliomesenchymal biphasic tumor in the duodenum: the first case of duodenoblastoma?

Epitheliomesenchymal biphasic neoplasms are extremely rare in the duodenum, and most of these are carcinosarcomas. Miettinen et al. (Am J Surg Pathol 33:1370-7, 2009) recently reported three cases of a novel distinctive epitheliomesenchymal biphasic tumor of the stomach in young adults. In view of the resemblance to other childhood blastomas, they proposed to refer to this entity as a gastroblastoma. Since none of the components were sufficiently atypical, the gastroblastoma seemed more comparable to this kind of tumor than carcinosarcomas or other aggressive and malignant biphasic tumors. This report describes a duodenal location of a similar epitheliomesenchymal biphasic tumor in a 22-year-old woman. To our knowledge, this is the first reported case occurring primarily in the duodenum and might be the first case of "duodenoblastoma."