Composite neuroendocrine tumor and adenocarcinoma of the rectum

Background

Although adenocarcinomas showing neuroendocrine differentiation or those mixed with high-grade neuroendocrine carcinoma (NEC) are sometimes encountered, composite tumors comprising neuroendocrine tumor (NET) Grade 1 and adenocarcinoma are exceedingly rare.

Case presentation

A 64-year-old male presented after testing positive for fecal occult blood at a medical check-up. A biopsy demonstrated the presence of a NET and endoscopic submucosal dissection was undertaken. Histologic examination revealed that a well differentiated tubular adenocarcinoma was present in addition to the NET. Furthermore, histological transition between the two tumors was evident. Accordingly, this case was considered to be a composite tumor comprising NET and adenocarcinoma.

Conclusion

Composite tumors consisting of NET Grade 1 and adenocarcinoma are exceedingly rare, and only a few examples have been reported hitherto.

     

Compensation of the rectum muscle dysfunction

The possibility of compensating for the inborn pathology of the obturative apparatus of the rectum has been examined. An adequate experimental model of encopresis and a method of transplantological compensation of this pathological state have been developed.