A neuroendocrine tumor of the small intestine with a karyotype of 46,XY,t(11;22).

Direct preparations of cells from a neuroendocrine carcinoma of the small intestine reveal a karyotype of 46,XY,t(11;22)(q25;q12). Though only 13 cells could be analyzed from both direct and 24 hour preparations, all revealed the translocation; no normal cell line was seen. The patient had not been treated at the time of biopsy. A similar translocation recently has been reported in a number of cases of Ewing's sarcoma and in peripheral neuroepithelioma. This common occurrence, along with the observation that a rearranged chromosome #22 with breakpoints at q11 or q12 are observed in other neoplasias including leukemia, suggests a possible causative role for these phenomena.