[PSAP expression in a primary presacral neuroendocrine tumor. Potential for confusion with prostate cancer].

Primary presacral neuroendocrine tumors are a rare entity with less than 30 cases described in the literature so far. Here we report of a primary presacral neuroendocrine tumor diagnosed at autopsy which was wrongly diagnosed as metastasized prostate cancer before. Misdiagnosis was due to the localization of the tumor, its morphology and its positivity for prostate-specific acid phosphatase (PSAP) when the patient was alive. This is the first report of PSAP and somatostatin receptor expression in this type of tumor.