%0 Journal Article %T Large cell neuroendocrine carcinoma (LCNEC) of the urinary bladder: a case report %A Cristina Colarossi %A Piero Pino %A Dario Giuffrida %A Eleonora Aiello %A Rosario Costanzo %A Daniela Martinetti %A Lorenzo Memeo %J Diagnostic Pathology %D 2013 %I BioMed Central %R 10.1186/1746-1596-8-19 %X The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2474700528951562. webciteNeuroendocrine carcinoma of the urinary bladder is a rare entity, accounting less than 1% of urinary bladder malignancies [1]. The vast majority of the neuroendocrine carcinomas of the urinary bladder is represented by small cell neuroendocrine carcinoma while just few cases of large cell neuroendocrine carcinoma (LCNEC) have been reported [1-9].LCNEC was first described by Travis [10] in the lung but cases of LCNEC were reported in other organs like uterus, thymus, stomach, bile duct, larynx, parotid gland, prostate, kidney, and cervix [11,12].In this cases report we describe a rare cases of primary bladder LCNEC.A 53 years old woman presented with asymptomatic hematuria in September 2011. Ultrasound studies revealed a 4 cm mass in the posterior wall of the urinary bladder. TC scan confirmed the presence of the lesion and demonstrated that both ureteral opening were involved by the tumor. Mesenteric lymph nodes were evident. The tumor was partially resected transurethrally. Microscopically, the tumor was composed of large pleomorphic cells with moderate amount of cytoplasm and coarse nuclear chromatin, organized in trabecular and rosette-like patterns and showed high mitotic rate (Figure 1).Immunohistochemical analysis demonstrated that tumor cells were diffusely positive for NSE (Figure 2), CD56 (Figure 3) and synaptophysin (Figure 4), focally positive for chromogranin and pan-cytokeratin (Figure 5) and negative for high molecular weight cytokeratin and TTF-1. The proliferation index, evaluated with Ki-67 was >95% (Figure 6). Tumor extension to the suburothelial connective was seen as well as lymphovascular invasion. The patient was diagnosed with primary large cell neuroendocrine carcinoma (LCNEC) of the urinary bladder. Since we found in the literature [13] a case of large cell neuroendocrine carcinoma of the lung harboring EGFR mutatio %U http://www.diagnosticpathology.org/content/8/1/19