Undiagnosed collecting duct carcinoma presenting as meningeal carcinomatosis and multiple bone metastases.

A 54-year-old woman presented with blepharoptosis, numbness in the lower lip, dysgeusia and pain in the extremities and back. MRI showed marked meningeal thickening and multiple bone lesions accompanying a prominent enhancing effect. CT scan of the chest and abdomen appeared to be unremarkable for primary cancer. She died 3 months after the admission, and postmortem autopsy showed a mass of about 2.5 cm in diameter in the renal medulla. Histological examination including immunohistochemistry confirmed the presence of a collecting duct carcinoma (CDC). This case is of particular interest because it emphasizes the possible fulminate clinical course of a small CDC.