Primary presacral neuroendocrine tumor associated with imperforate anus

BACKGROUND Presacral masses are unusual growths that have a limited differential diagnosis, typically not including neuroendocrine tumors (NETs). Classically, NETs are well-differentiated gastroenteropancreatic tumors of probable benign behavior. These tumors are associated with a typical morphologic pattern and involve the distal colon, rectum, and genitourinary tract; they are considered less aggressive, frequently asymptomatic, and rarely cause carcinoid syndrome, even when metastatic. Neuroendocrine tumors of the presacral region are extremely rare and few have been described in the literature. They have not been previously reported as being associated with imperforate anus. CASE PRESENTATION We present an interesting case of a woman with a history of imperforate anus that was found to have a primary neuroendocrine tumor of the presacral region with no rectal wall involvement. CONCLUSION We argue that this is a primary gastroenteropancreatic neuroendocrine tumor which likely originated from cells of hindgut origin that underwent an abnormal migration during embryonic development.