Leptomeningeal carcinomatosis presenting as progressive multineuritis: clinical, pathologic, and MRI study

Two patients developed a persistent illness characterized clinically and electrophysiologically by asymmetric involvement of spinal roots, of cranial and peripheral nerves. In the first case the disease was not discovered clinically but only after autopsy. The primary neoplasm remained undetected at autopsy. There was profound infiltration of the leptomeninges by tumor cells with features of metastatic adenocarcinoma. In the second patient onset of neurological symptoms occurred 16 years after surgery for breast cancer, which may be reasonably considered the primary malignancy-CSF cytology was positive only in the second patient in whom Gd-DTPA MRI supported the diagnosis. Our cases demonstrate that diagnosis in leptomeningeal carcinomatosis may be a challenging clinical problem.