Case Study of the Month Development of Carcinoid Tumour in Hormonally Treated Adenocarcinoma of the Prostate Joery P.F. Molenaar a, *, Anique Baten b , Willeke A.M. Blokx c , Arjen Hoogendam b a Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands b Division of General Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands c Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands 1. Case report An 81-yr-old man was admitted at our hospital because of unexplained episodic fever. He had been suffering from these episodes for 2 yr, approximately five times per year. The fever never exceeded 39 8C and lasted for 3–4 d. At times, it was accompanied by diarrhoea. Previous analysis revealed multiple tumours in his liver; however, this did not lead to a diagnosis, despite biopsy. Our patient was known to have a T3aG1NxMx adeno- carcinoma of the prostate, for which he was treated with bicalutamide (Casodex) for 3 yr. During physical examination, we found an enlarged liver, palpable 4 cm under the rib cage, and an enlarged smooth prostate. Abdominal ultrasonography and positron emis- sion tomography–computed tomography (PET-CT) scan (Fig. 1) showed numerous liver lesions. Furthermore, an active lesion was found in multiple vertebrae, and increased metabolic activity was spotted in the right lung hilus. Biopsy of the liver revealed a localisation of a neuroendo- crine (NE) tumour (carcinoid; Fig. 2). To confirm the diagnosis of a carcinoid, 24-h urine was collected for 5-hydroxyindoleacetic acid (5-HIAA) and chromogranin A was determined. The values found were 3165 mmol/l (<50) and 10 945 U/l (<120), respectively, and were highly suggestive of a carcinoid tumour. We revised the previously taken biopsies of the prostate, thinking this might be the primary tumour EUROPEAN UROLOGY 56 (2009) 874–877 available at www.sciencedirect.com journal homepage: www.europeanurology.com Article info Article history: Accepted January 9, 2009 Published online ahead of print on January 20, 2009 Keywords: Prostate Adenocarcinoma Hormone refractory Carcinoid Carcinoid syndrome Neuroendocrine differentiation Androgen deprivation therapy Abstract We present the case of an 81-yr-old man with a prostatic adenocarcinoma and a metastatic carcinoid. Simultaneous occurrence of hormonally treated adenocarci- noma of the prostate and a carcinoid has been described before. The pathogenesis of this coincidence is largely unclear; however, androgen deprivation therapy might play a key role in neuroendocrine differentiation of adenocarcinoma cells. Early recognition of the carcinoid syndrome is crucial, as surgical cure is not possible after metastasis. We provide a brief review of recent literature. # 2009 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Pegasusplaats 233, 6525 JK Nijmegen, The Netherlands. E-mail address: joerymolenaar@student.ru.nl (Joery P.F. Molenaar). 0302-2838/$ – see back matter # 2009 European Association of Urology. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.eururo.2009.01.019