De novo large‐cell neuroendocrine carcinoma of the prostate: A case report and literature review

INTRODUCTION: Prostatic large‐cell neuroendocrine carcinoma is poorly studied. Although several case reports are available, information on the clinicopathological characteristics of this disease is limited, particularly for the de novo (hormone‐naive) type. Herein, we report an extremely rare de novo case of this disease with a good prognosis despite a multi‐metastatic status. CASE PRESENTATION: An 83‐year‐old male patient presented with a high serum prostate‐specific antigen level and was found to have de novo prostatic large‐cell neuroendocrine carcinoma with an adenocarcinoma component upon pathological examination. Diagnosed with stage pT4cN1cM1c, he underwent chemo‐hormonal therapy using a luteinizing hormone‐releasing hormone antagonist and combined etoposide and cisplatin, which achieved a partial response. The patient has survived for 20 months without progression. CONCLUSION: Although prostatic large‐cell neuroendocrine carcinoma is known for its aggressive clinical behavior, the de novo type with an adenocarcinoma component may be sensitive to hormonal therapy and achieve a good prognosis.