Widespread neuroendocrine malignancy within the central nervous system: a diagnostic conundrum

A 75 year old female presented with a sellar tumour, and was subsequently found also to have a cauda equina tumour, a parietal dural tumour, a pontine tumour, an intradural spinal tumour, and several vertebral body tumours. Histological examination revealed a neuroendocrine tumour forming cell nests surrounded by reticulin. There was moderate nuclear pleomorphism, prominent mitoses, and focal necrosis. Immunohistochemistry showed diffuse positive staining with cytokeratins, chromogranin and 5-hydroxytryptamine, and focal positive staining with S100. This case is an unusual and ultimately insoluble, diagnostic problem; however, the differential diagnoses include pituitary carcinoma, malignant paraganglioma, and atypical carcinoid.