Leptomeningeal metastases from ethmoid sinus adenocarcinoma: clinico-radiological correlation

A patient with sinonasal adenocarcinoma is presented with leptomeningeal metastases affecting multiple cranial nerves and spinal nerve roots. Head and neck cancer is known to be an extremely rare source for leptomeningeal metastatic spread. The cranial nerves, the spinal cord and roots and the cerebral hemispheres can be affected in case of leptomeningeal metastatic spread. Examination of the CSF is the hallmark of the diagnosis if leptomeningeal metastatic spread is suspected, but this case illustrates that the combination of specific clinical features on one hand and specific lesions on the Gd-enhanced T1-weighted MRI study on the other hand is reliable enough to make a presumed diagnosis if the CSF analysis remains negative. We suggest that in our patient direct leptomeningeal spread occurred through the cribriform plate to the CSF, followed by further spread in a gravity dependent way.