Introduction: Primary tumors of seminal vesicles are rare and only a few cases have been reported. Diagnosis is difficult due to the absence of early clinical signs. Prognosis is generally poor.
Case presentation: We present the case of a 70-year-old Caucasian man with a seminal vesicle mass and concomitant lymph node metastasis detected by computed tomography and body positron emission tomography/low-dose computed tomography scan carried out for evaluation of Lambert Eaton syndrome. Transrectal ultrasound-guided biopsy showed a poorly differented neuroendocrine carcinoma with an immunhistochemical profile similar to small cell lung cancer. Following chemotherapy the disease was stable and active surveillance was initiated.
Conclusions: Lambert Eaton syndrome may be the initial symptom of a seminal vesicle mass. Diagnosis needs to be obtained by transrectal biopsy and chemotherapy may delay progression of the tumor.