Sentinel lesions of primary CNS lymphoma.

Abstract

Some patients ultimately diagnosed with primary CNS lymphoma (PCNSL) have transient symptomatic contrast enhancing lesions. These "sentinel lesions" of PCNSL recede spontaneously or with corticosteroid treatment and present an important diagnostic dilemma because they show variable, but non-diagnostic histopathological features.Four previously healthy, immunocompetent patients aged 49 to 58 years had contrast enhancing intraparenchymal brain lesions. Before biopsy, three of the four were treated with corticosteroids. Initial biopsies showed demyelination with axonal sparing in two, non-specific inflammation in one, and normal brain in one. Infiltrating lymphocytes predominantly expressed T cell markers with rare B cells. All four patients recovered within two to four weeks after the initial biopsy and imaging studies showed resolution of the lesions. The CSF was normal in three of the four patients tested; oligoclonal bands were absent in both of the two tested.After seven to 11 months, each patient developed new symptomatic lesions in a different region of the brain, biopsy of which showed a B cell PCNSL. The mechanism of spontaneous involution of sentinal lesions is not understood, but may represent host immunity against the tumour. Sentinel lesions of PCNSL should be considered in patients with contrast Seven months later she again noted fatigue, disorientation, left sided weakness, and visual impairment. Brain CT showed enhancing lesions in the septum pellucidum, head of the right caudate, splenium of the corpus callosum, and at multiple sites in the periventricular white matter. The prior biopsy site in the hypothalamus appeared as a small lucency without enhancement. A stereotactic biopsy of the right caudate lesion in July 1990 showed a B cell lymphoma of the diffuse large cell subtype.

Expression of B-cell–attracting chemokine 1 (CXCL13) by malignant lymphocytes and vascular endothelium in primary central nervous system lymphoma

“…It is intriguing that some patients with PCNSL may demonstrate benign inflammatory intraparenchymal brain lesions that resolve prior to the development of tumor. 34 Conversely, PCNSL may represent malignant transformation within a benign lymphocytic proliferation, a scenario that may explain many MALT lymphomas 11,15 In this setting, activated CD4 ϩ T-helper cells promote low-grade B-cell neoplasia in response to chronic antigen stimulation. 35 Most B-cell lymphomas show variable infiltration by benign T cells.…”

Central Nervous System Lymphoma Initially Diagnosed as Tumefactive Multiple Sclerosis after Brain Biopsy

“…Both PCNSL and demyelinating diseases respond to corticosteroid therapy or improve spontaneously, which makes it difficult to differentiate these disorders (1)(2)(3)(4)(5). However, making a definitive diagnosis is necessary because the treatments and long-term outcomes of these disorders are very different.…”

Demyelination After Primary Central Nervous System Lymphoma; Reversed ‘Sentinel’

“…Several case reports described demyelinating pseudotumoral lesions preceding PCNSl 3,4 . All of these, so called, 'sentinel' demyelinating lesions occurred prior to PCNSl and receded spontaneously or after corticosteroid treatment.…”