Isolated CNS Hodgkin's lymphoma: implications for tissue diagnosis.

CNS involvement in the setting of lymphoid neoplasia is a clinical situation that requires specific diagnosis due to the disparate treatment regimens recommended for neoplasms of specific lymphoid cell types. Cerebrospinal fluid (CSF) sampling may provide sufficient information to determine the presence of abnormal lymphoid cells but may not be able to further specify the malignant cellular population. In cases where abnormal clinical or radiographic features are present, accurate tissue diagnosis is essential. In this report, we define a rare case of primary CNS intramedullary Hodgkin's lymphoma without leptomeningeal dissemination diagnosed via resectional biopsy of a conus medullaris lesion. The patient received post-resection radiation therapy and subsequently demonstrated radiographic and clinical improvement. Lymphoid neoplasia within the CNS comprises a diverse group with varying response and survival rates. Treatment hinges upon accurate diagnosis as chemotherapy varies widely among Hodgkin's and non-Hodgkin's lymphoma. While CSF sampling may yield a positive result with sufficiency to diagnose an abnormal lymphoid cell population, tissue is necessary for further defining cellular pathology. In this report, we define a rare case of primary CNS intramedullary Hodgkin's lymphoma without leptomeningeal dissemination via resectional biopsy of a conus medullaris lesion. In cases where abnormal enhancement is found in eloquent CNS regions and lymphoid neoplasia is suspected, management often entails either stereotactic biopsy or CSF sampling. While CSF analysis may differentiate malignancy at a low rate, tissue diagnosis via paraffin block immunohistochemistry is necessary to further classify malignancy as primary or peripheral, Hodgkin's or non-Hodgkin's lymphoma, or other such as metastatic leptomeningeal dissemination and glioma. Within the subtypes of lymphoid neoplasms, treatment regimens vastly differ and thus accurate tissue diagnosis is paramount. We therefore present a rare case of primary CNS intramedullary Hodgkin's lymphoma without leptomeningeal disease in the setting of immunocompromise diagnosed via open resectional biopsy of the conus medullaris.