Imaging description

With the advent of modern chemotherapeutic medicine, sophisticated delivery of radiation, and efficient management of complex side effects and complications, cancer patients are living longer. There is also increasing incidence of leptomeningeal cranial and spinal metastasis due to the spread of malignant tumor cells through the subarachnoid space, which is typically seen in advanced cancer cases [1]. However, in 20% of patients it can present after a disease-free interval, and in 5–10% of cases it can be the first manifestation of cancer [1].

CSF analysis is one of the earliest investigations in patients presenting with myelopathy and polyradiculopathy. However, for positive analysis in a case of leptomeningeal metastatic disease, multiple CSF sampling may be necessary to get positive cytology [2]. Drop metastasis from primary CNS tumor is most commonly seen with medulloblastoma in children (Fig. 106.1). It can be seen in cases of intracranial ependymoma (Fig. 106.2), germinoma, or choroid plexus papilloma. In adults, it is more commonly seen in cases of anaplastic astrocytoma (Fig. 106.3), glioblastoma (Fig. 106.4), or ependymoma [3]. Disseminated hematogenous spread from an extracranial malignant neoplasm is commonly seen with adenocarcinomas, more commonly from breast (Fig. 106.5) or lung. It can also be seen from adenocarcinoma of the gastrointestinal tract, such as esophagus or stomach [4]. Sometimes drop metastasis from rare intracranial conditions such as primary leptomeningeal oligodendroglioma is also seen (Fig. 106.6). Other systemic conditions, including melanoma, leukemia, and non-Hodgkin’s lymphoma, are also associated with an increasing incidence of leptomeningeal spinal metastasis.