Occult systemic non-Hodgkin's lymphoma (NHL) in patients initially diagnosed as primary central nervous system lymphoma (PCNSL): how much staging is enough?

OBJECTIVE: To demonstrate the extent of staging necessary to exclude occult systemic stage IV NHL before making a diagnosis of stage I AE PCNSL.
BACKGROUND: The diagnosis of PCNSL requires the demonstration of malignant lymphocytes within the CNS (usually by biopsy) and finding no evidence of systemic NHL. Different staging approaches have been recommended, ranging from extensive systemic evaluation (including bone marrow examination) to a more focused approach (abdominal and pelvic CT) to no systemic evaluation. We have employed a staging regimen that included: ophthalmologic evaluation (including slit lamp examination); CT of chest, abdomen, and pelvis; bilateral iliac crest aspirate and biopsy; flow cytometry of circulating lymphocytes; and, in men, testicular ultrasound. DESIGN/
METHODS: We carried out a retrospective review of 128 patients entered into the Mayo Lymphoma Project data bank (1975-1994).
RESULTS: Between the years 1975 and 1994, five patients (3.9%) were identified who fulfilled criteria for the diagnosis of PCNSL (typical clinical history, pathognomonic neuro-imaging, and histologic proof of NHL in brain tissue) but who had occult systemic NHL on staging (bone marrow 1, abdominal lymph nodes 3), or at autopsy (colon 1). Case histories are presented.
CONCLUSIONS: Patients with apparent PCNSL may have systemic NHL. Complete staging is essential to the initial management of patients presenting as PCNSL to exclude systemic stage IV disease.