CT and MRI Findings of Intracranial Lymphoma

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1 Neuroradiology- Slone et al. CT and MRI of Intracranial Lymphoma Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved Pictorial Essay CT and MRI Findings of Intracranial Lymphoma rimary CNS lymphoma is the confinement of extranodal lymphoma P to the CNS. Classically, lymphomas are divided into Hodgkin s lymphoma and non-hodgkin s lymphoma, with a primary extranodal presentation in 5% and 30% of cases, respectively. With an increasing incidence in both the immunocompetent and immunocompromised populations, primary CNS lymphoma represents 1% of all lymphomas and as many as 16% of all primary brain tumors [1]. This amplified prevalence makes primary CNS lymphoma an important consideration in the differential diagnosis of brain lesions. This pictorial essay will review the varied CT and MRI appearances of intracranial lymphomas. Primary CNS Lymphoma in the Immunocompetent Most primary CNS lymphomas are of the non-hodgkin s -cell type [1]. -cell primary CNS lymphoma typically presents when the patient is approximately 50 years old and is more frequent in men. The most common presenting symptom is a change in mental status followed by nausea, headache, hemiparesis, cerebellar signs, cranial nerve palsies, and visual disturbances [1, 2]. Cerebrospinal fluid analysis yields a cytologic diagnosis in fewer than half of patients with -cell primary CNS lymphoma. H. Wayne Slone 1, Joseph J. lake, Rajul Shah, Sangeeta Guttikonda, Eric C. ourekas Slone HW, lake JJ, Shah R, Guttikonda S, ourekas EC Neuroimaging reveals solitary lesions that are most commonly located supratentorially in the white matter of the frontal or parietal lobes or in the subependymal regions, but the lesions may also involve the deep gray matter (Figs. 1 and 2). In 12% of -cell primary CNS lymphomas, the leptomeninges are involved [1]. CT scans usually show high attenuation, probably because of high cellularity, and virtually all lesions show homogeneous contrast enhancement (Fig. 1). On MRI, -cell primary CNS lymphoma lesions are clearly delineated masses that appear isointense to hypointense on T1-weighted images and mostly hypointense on T2-weighted images [1, 2] (Fig. 1). Nearly all lesions show homogeneous enhancement with contrast material (Fig. 1C). classic presentation is the lesion that crosses the corpus callosum in a butterfly pattern (Fig. 3). Rarely, necrosis, cyst formation, calcification, and hemorrhage can be seen. If steroids are administered, the tumor may shrink and vanish, compromising the ability to obtain a histologic diagnosis (Fig. 4). Received July 26, 2004; accepted after revision November 8, Presented at the 2004 annual meeting of the merican Roentgen Ray Society, Miami each, FL. Primary CNS Lymphoma in the Immunocompromised Immunocompromised patients are at increased risk for developing primary CNS lymphoma. In fact, estimates indicate that nearly 6% of the IDS population will be afflicted with an intracranial lymphoma [3]. Indeed, primary CNS lymphoma in an HIV-seropositive patient is an IDS-defining condition. The age at presentation is earlier (fourth decade) in immunocompromised patients than in the immunocompetent, but the cell type ( cell) and presenting signs and symptoms are similar. Neuroimaging reveals a higher frequency of multiple lesions and more often displays irregular margins, heterogeneity, and ring enhancement [1, 3] (Figs. 5 and 6). In the immunocompromised population, an important dilemma is the difficulty in distinguishing primary CNS lymphoma from the more common cerebral toxoplasmosis using CT and MRI, because both entities can present with multiple ring-enhancing lesions. Thallium SPECT or PET can aid in this setting, although frequently the patient is treated for presumed toxoplasmosis, and if the patient responds the diagnosis is established. Primary Leptomeningeal Lymphoma lthough extension of primary CNS lymphoma into the leptomeninges is common, primary leptomeningeal lymphoma is rare, constituting fewer than 8% of all cases of primary CNS lymphoma [4]. The clinical presentation of primary leptomeningeal lymphoma is similar to that of -cell primary CNS lymphoma but may also include dizziness, tinnitus, spinal neuropathies, and meningismus. The diag- 1 ll authors: Department of Radiology, The Ohio State University Medical Center and The Ohio State University College of Medicine and Public Health, 629 Means Hall, 1654 Upham Dr., Columbus, OH ddress correspondence to H. W. Slone (slone-1@medctr.osu.edu). JR 2005;184: X/05/ merican Roentgen Ray Society JR:184, May

2 Slone et al. Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved C Fig year-old immunocompetent woman with primary CNS non-hodgkin s -cell lymphoma who presented with progressive motor weakness., Unenhanced CT image shows classic hyperdense masses involving deep white and gray matter., xial FLIR MR image shows isointensity of lesions to brain parenchyma and surrounding edema. C, xial contrast-enhanced T1-weighted MR image shows homogeneous enhancement of multiple bilateral tumors. nosis is often elusive because clinical findings are often suggestive of meningoencephalitis or common conditions that cause increased intracranial pressure. nalysis of the cerebrospinal fluid of patients with primary leptomeningeal lymphoma has failed to show a consistent presence of malignant cells. Neuroimaging is often unremarkable or may show nonspecific findings such as hydrocephalus. On occasion, significant imaging findings may include widespread meningeal calcification, discrete masses or densities, and faint meningeal enhancement (Figs. 7 and 8). In the absence of other findings, protondensity or FLIR MRI revealing the presence of high signal intensity in the subarachnoid space may support a diagnosis of primary leptomeningeal lymphoma. Metastatic CNS Lymphoma, -Cell Type In 5 9% of systemic non-hodgkin s lymphoma, secondary spread involves the CNS [5], usually in the form of leptomeningeal infiltrates, and has a poor prognosis. Parenchymal lesions, when present, typically result from secondary involvement from the leptomeninges via infiltration of the perivascular spaces (Fig. 9). Intravascular Lymphomatosis With fewer than 50 reported cases, intravascular lymphomatosis is an extraordinarily rare form of large -cell non-hodgkin s lymphoma that is characterized by aggressive, intravascular proliferation of lymphoid cells. Proclivity for involvement and subsequent occlusion of CNS vessels often leads to nonlocalizing neurologic deficits and changes in mental status. ecause no specific clinical or Fig year-old immunocompetent woman with primary CNS non-hodgkin s -cell lymphoma with leptomeningeal spread who presented with left hemiparesis, severe headache, and confusion. Systemic workup was negative. Cerebrospinal fluid cytology was positive for leptomeningeal spread., xial FLIR MR image shows high-signal-intensity edema in white matter around trigone of left lateral ventricle., Contrast-enhanced coronal T1-weighted MR image shows focal enhancing lesion in deep white matter of left parietal and posterior temporal regions with enhancement of adjacent subependyma (arrow) JR:184, May 2005

3 Fig year-old immunocompetent man with primary CNS non-hodgkin s -cell lymphoma., xial T2-weighted MR image shows infiltrative hyperintense mass expanding genu and splenium of corpus callosum in butterfly pattern., Contrast-enhanced axial T1-weighted MR image shows homogeneous enhancement of lesion. CT and MRI of Intracranial Lymphoma Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved Fig year-old immunocompetent man with primary CNS non-hodgkin s -cell lymphoma and vanishing hyperdense masses when treated with steroids. Systemic workup was negative., Initial axial CT image shows hyperdense masses in basal ganglia bilaterally., On follow-up CT image obtained 10 days after initiation of steroids, lesions have nearly resolved, consistent with vanishing tumor. C Fig year-old HIV-positive woman with primary CNS non-hodgkin s -cell lymphoma. She presented with changes in mental status and CD-4 count of 0., Contrast-enhanced CT image shows low-density infiltrating butterfly lesion crossing corpus callosum with ring of enhancement (arrows)., xial FLIR MR image shows lesion isointense to gray matter (arrows). C, Contrast-enhanced T1-weighted axial MR image shows ring of enhancement (arrows). JR:184, May

4 Slone et al. Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved C Fig year-old HIV-positive man with primary CNS non- Hodgkin s -cell lymphoma. Presenting signs were third and fourth cranial nerve palsies. Patient underwent irradiation 1 year earlier for stage I palate cancer., xial FLIR MR image shows lesion involving left cerebral peduncle., Contrast-enhanced coronal T1-weighted MR image shows masslike enhancement. C, Contrast-enhanced coronal T1-weighted MR image shows enhancement along third and fourth cranial nerves (arrow). C Fig year-old woman with primary meningeal lymphoma who presented with frequent falls and vertigo. CT scan from outside institution (not shown) showed hyerdensity along surface of parietotemporal covexity that was incorrectly interpreted as subdural hemorrhage. Systemic workup was negative., xial FLIR image shows hyperintensity (arrow) involving sulci and leptomeninges of parietotemporal convexity. and C, Contrast-enhanced T1-weighted axial () and coronal (C) MR images show focal thickening and homogeneous enhancement of leptomeninges of parietotemporal convexity (arrows) JR:184, May 2005

5 CT and MRI of Intracranial Lymphoma Fig year-old man with IDS and primary CNS non-hodgkin s -cell lymphoma of leptomeninges who presented with diplopia, facial weakness, and eyelid droop. No parenchymal lesions were identified. Coronal contrast-enhanced T1-weighted MR image shows enhancement of multiple cranial nerves (arrows) bilaterally. Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved laboratory findings are associated with intravascular lymphomatosis, the diagnosis is rarely established before histologic examination during autopsy. MRI findings in intravascular lymphomatosis include high-signal deep white matter lesions and infarctlike, high-signal lesions in vascular territories on T2-weighted images. fter the administration of contrast material, enhancement can be masslike [6] (Fig. 10). Various patterns of parenchymal and meningeal enhancement may also be seen. Primary CNS Lymphoma, T-Cell Type Primary T-cell lymphoma of the CNS constitutes a small fraction of all primary CNS lymphomas in the immunocompetent population. threefold higher incidence of T-cell primary CNS lymphoma in Japan compared with the United States has been reported. In a review of 25 cases of T-cell primary CNS lymphoma, Liu et al. [7] reported that T-cell primary CNS lymphoma is similar to -cell primary CNS lymphoma in clinical presentation and imaging features. Unlike -cell primary CNS lymphoma, involvement of the cerebrospinal fluid in T-cell primary CNS lymphoma is uncommon. CT and MRI typically show one or more homogeneous masses that uniformly enhance with contrast material [7] (Fig. 11). ssociation with IDS or other types of immunodeficiency has only rarely been reported. Intracranial Hodgkin s Lymphoma Fewer than 0.5% of patients with Hodgkin s lymphoma have CNS involvement, and most of these cases are late manifestations of disseminated disease outside the CNS. Primary intracranial Hodgkin s lymphoma, with only a few case reports, is perhaps the rarest of all intracranial lymphomas. In the reported cases, neuroimaging usually shows meningeal involvement. Intracranial Hodgkin s lymphoma may mimic meningioma, although parenchymal lesions without meningeal attachment have been reported [8] (Figs. 12 and 13). Conclusion The CT and MRI findings of intracranial lymphomas can be nonspecific or share common features with other diseases such as demyelinating disorders, other neoplasms, sarcoid, tuberculosis, and toxoplasmosis. Therefore, a definitive diagnosis of primary Fig year-old woman with metastatic leptomeningeal CNS non-hodgkin s -cell lymphoma who presented with left facial droop. She was previously diagnosed with systemic stage IV non-hodgkin s lymphoma (-cell type)., xial contrast-enhanced T1-weighted MR image shows linear leptomeningeal enhancement (arrows). Enhancement of fifth cranial nerve (arrowhead) is evident as well., Coronal contrast-enhanced T1-weighted MR image shows enhancement of fifth, seventh, and eighth cranial nerves (arrows). JR:184, May

6 Slone et al. Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved C Fig year-old man with intravascular non-hodgkin s -cell lymphoma who presented with left leg weakness for 1 year., xial FLIR MR image shows hyperintense deep white matter signal., Diffusion-weighted axial MR image shows restricted diffusion of lesion. C, Contrast-enhanced axial T1-weighted MR image shows nodular enhancement. Fig year-old man with primary CNS non-hodgkin s T-cell lymphoma who presented with seizure., xial FLIR MR image shows hyperintense signal in tectum and posterior aspect of midbrain (arrow)., xial contrast-enhanced T1-weighted MR image shows leptomeningeal enhancement (arrows). Fig year-old woman with primary Hodgkin s lymphoma who presented with progressive left-sided weakness. Systemic workup was negative., Contrast-enhanced CT image shows enhancement along frontoparietal convexity., Contrast-enhanced T1-weighted coronal MR image shows dura-based enhancing lesion with dural tail (arrows) causing compression of frontal lobe and subfalcine herniation JR:184, May 2005

7 CT and MRI of Intracranial Lymphoma Downloaded from by on 02/10/18 from IP address Copyright RRS. For personal use only; all rights reserved CNS lymphoma requires histologic assessment. However, a high index of suspicion and the presence of features similar to those illustrated in this article can aid in the diagnosis of intracranial lymphoma. Fig year-old HIV-positive man with systemic nodular sclerosing Hodgkin s lymphoma who presented with mental status change. Last CD-4 count was more than 1,200 per cubic millimeter with undetectable viral load. Patient did not respond to antitoxoplasmosis treatment and underwent biopsy., xial unenhanced CT image shows hypodense vasogenic edema around subtle hyperdense lesion (arrow) along medial margin of left parietooccipital lobe., xial T2-weighted MR image shows low signal intensity of lesion (arrow). C, xial T1-weighted contrast-enhanced MR image shows leptomeningeal enhancement (arrows). References 1. Koeller KK, Smirniotopoulos JG, Jones RV. Primary central nervous system lymphoma: radiologic-pathologic correlation. RadioGraphics 1997;17: Coulon, Lafitte F, Hoang-Xuan K, et al. Radiographic findings in 37 cases of primary CNS lymphoma in immunocompetent patients. Eur Radiol 2002;12: Thurnher MM, Rieger, Kleibl-Popov C, et al. Primary central nervous system lymphoma in IDS: a wider spectrum of CT and MRI findings. Neuroradiology 2001;43: Lachance DH, O Neil P, Macdonald DR, et al. Primary leptomeningeal lymphoma: report of 9 cases, diagnosis with immunocytochemical analysis, and review of the literature. Neurology 1991;41: Goetz P, Lafuente J, Revesz T, Galloway M, Dogan, Kitchen N. Primary low-grade -cell lymphoma of mucosa-associated lymphoid tissue of the dura mimicking the presentation of an acute subdural hematoma. J Neurosurg 2002;96: Martin-Duverneuil N, Mokhtari K, ehin, Lafitte F, Hoang-Xuan K, Chiras J. Intravascular malignant lymphomatosis. Neuroradiology 2002;44: Liu D, Schelper RL, Carter D, et al. Primary central nervous system cytotoxic/suppressor T-cell lymphoma. m J Surg Pathol 2003;27: Deckert-Schluter M, Marek J, Setlik M, et al. Primary manifestation of Hodgkin s disease in the central nervous system. Virchows rch 1998;432: C JR:184, May