Lymphomatosis cerebri: diagnostic challenges and review of the literature

A Case of Lymphomatosis Cerebri Presenting with Rapid Progression of Dementia: A Literature Review

Lymphomatosis cerebri is an atypical form of primary central nervous system lymphoma (PCNSL), which frequently causes rapid progression of dementia. A 68-year-old woman exhibited rapidly progressing disorientation and a mini-mental state examination score of 9. The fluid-attenuated inversion recovery of a magnetic resonance image (MRI) demonstrated focal areas of high-signal intensity in the right frontal lobe with a small enhancement, which was histologically diagnosed as diffuse large B-cell type lymphoma. The lesion dramatically shrank, and no enhancements were identified on MRI after treatment with high-dose methotrexate (MTX) and whole-brain radiation (WBR). However, her recovery of cognitive function was poor. The patient visited our clinic every 2 months but succumbed to systemic mycotic sepsis 14 months after the biopsy. Autopsy revealed lymphomatosis cerebri in the patient based on a feature of scattered small clusters of lymphoma cells infiltrating into the brain parenchyma in both cerebral hemispheres. Differentiation of lymphomatosis cerebri from other white matter degenerative diseases is usually challenging because lymphomatosis cerebri seldom forms mass lesions. In lymphomatosis cerebri, the lymphoma cells infiltrate into several regions in the brain tissue, including the basal ganglia, brainstem, and corpus callosum, in addition to periventricular and subcortical white matters. The rapid deterioration of cognitive function in the patient suggests a rapid spread of lymphomatosis cerebri, necessitating early histological diagnosis and prompt treatments. If the diagnosis is obtained, administration of high-dose MTX and WBR followed by rituximab and cytarabine can contribute to a longer survival time, based on our literature review.

Numerous spindle-shaped lymphoma cells in lymphomatosis cerebri: An autopsy case report

Lymphomatosis cerebri (LC) is a rare variant of primary central nervous system lymphoma (PCNSL). It is characterized by diffuse infiltration of atypical lymphoid cells with no mass formation and little or no contrast enhancement on magnetic resonance imaging (MRI). Interestingly, some lymphoma cells form characteristic spindle shapes; these cells are found in some variants of malignant lymphoma, such as primary cutaneous follicle center lymphoma, but they have not been reported in PCNSL or LC. Here, we provide an autopsy case report of LC in a 69-year-old immunocompetent man who developed rapidly progressive cognitive decline and died on day 68 after the episode despite treatment with intravenous methylprednisolone administration. MRI revealed high signal intensities on T2-weighted images of the cerebral hemispheres, cerebellum, brainstem, and spinal cord without gadolinium enhancement on T1-weighted images. On autopsy, diffuse infiltrative atypical cells were seen; these cells were positive for CD20 and CD79a and negative for GFAP, CD3, and CD5 on immunohistochemistry, resulting in a diagnosis of diffuse large B-cell lymphoma, specifically LC. We found characteristic spindle-shaped cells, especially in the cerebral cortex. This is the first report showing that lymphoma cells in PCNSL can take on a spindle-shaped form. It is difficult to recognize these spindle-shaped cells as lymphoma cells on hematoxylin and eosin staining and diagnose them correctly with small biopsy specimens without immunohistochemistry. This case suggests that we should add atypical, spindle-shaped cells to the differential diagnosis of PCNSL.

Diffuse Infiltrative Non-mass-like Brain Parenchymal Lesions on MRI: Differentiating Lymphomatosis Cerebri from its Mimics

Objectives:

Diffuse infiltrative “non-mass-like” parenchymal lesions on MRI brain are a known presentation of an aggressive condition called lymphomatosis cerebri (LC) but are often misdiagnosed due to its non-specific clinical and imaging findings. We aim to identify clues to differentiate lymphomatosis from its less aggressive mimics based on imaging features.

Material and Methods:

MRI brain studies showing diffuse infiltrative “non-mass-like” parenchymal lesions between January 2013 and March 2020 were retrospectively identified and read for lesion location, signal characteristics, and enhancement pattern by two radiologists. Additional findings on MRI spine and whole-body fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) were recorded wherever available. The clinical diagnosis, patient demographics, symptoms, laboratory and histopathology results, treatment details, and follow-up details were also noted.

Results:

Of the 67 patients, 28 (41.7%) were diagnosed with lymphomatosis. The remaining 39 (13.4%) patients were classified as non-lymphomas (infective, vasculitis, and inflammatory conditions). Diffusion restriction on MRI (20/67, P = 0.007) and increased regional activity on FDG PET-CT (12/31, P = 0.017) were the two imaging parameters found to significantly favor lymphomatosis over other conditions, whereas the presence of microhemorrhages on susceptibility-weighted imaging was significantly associated with vasculitis (P = 0.002). Rapid clinical or imaging deterioration on a short trial of steroids (P = 0.00) was the only relevant clinical factor to raise an early alarm of lymphomatosis. Positive serological markers and non-central nervous system systemic diseases were associated with non-lymphomatous diseases.

Conclusion:

LC and its less aggressive mimics can be differentiated on diffusion-weighted imaging-MRI and PET-CT when read in conjunction with rapid progression of clinical features, serological workup, and systemic evaluation.

[A case of lymphomatosis cerebri rapidly confirmed by brain biopsy]

Lymphomatosis cerebri (LC) is a variant of primary central nervous system lymphoma, which demonstrates diffuse white matter infiltrates without showing definite enhanced mass lesions on MR scans. We present a case of seventy-one year-old immunocompetent male who manifested with progressive truncal ataxia and drowsiness. The MRI exhibited diffuse white matter lesions from brainstem to cerebral hemispheres with minimum enhanced lesions at the first presentation. Because the diagnosis of LC was suspected, we performed a brain biopsy from the enhanced lesion near the right thalamus, which revealed diffuse large B cell lymphoma. After he underwent methylprednisolone pulse therapy and methotrexate chemotherapy, he obtained remission. Making a diagnosis of LC is often difficult because image findings resemble those of inflammatory or autoimmune diseases. LC is an important differential diagnosis to be considered in patients presenting with diffuse white matter disease. Performing a brain biopsy at the early phase is essential for the correct diagnosis and the favorable prognosis.

Diffuse large B-cell lymphoma of the central nervous system presenting as "lymphomatosis cerebri" and dementia in elderly man: Case report and review of the literature

RATIONALE

Lymphomatosis cerebri is a rare form of PCNSL, characterized by diffuse infiltration of lymphoma cells in cerebral parenchyma, without mass-formation and mild or no contrast enhancement on magnetic resonance (MR) imaging. There are less than 50 cases described in the literature under the term Lymphomatosis cerebri.

PATIENT CONCERNS

A 74-year-old man presented to our service with progressive dementia for 12 months and accelerated cognitive decline within the last two months. Brain magnetic resonance imaging showed areas of hyperintensity involving predominantly the white matter of frontal lobes and knee of the corpus callosum, along with areas of blood-brain barrier disruption and areas of restricted diffusion. Stereotaxy brain surgery was indicated into contrasting areas and histologically there was heterogeneous foci of discreet infiltration of rare medium-large lymphoid cells intermingled with inflammatory cells and these atypical lymphoid cells were placed on breakdown neuropil and did not form tumor mass or sheets of cells, but occasionally displayed perivascular distribution. Immunohistochemically, these atypical lymphoid cells expressed CD20, Bcl2, Bcl6 and, heterogeneously, IRF4/MUM1.

DIAGNOSIS

The diagnosis of a primary CNS diffuse large B-cell lymphoma manifested as lymphomatosis cerebri was performed.

INTERVENTIONS

The treatment of choice was: temozolomide 100 mg/m (D1 to D5), methotrexate 3 g/m (D1, D10, and D20) and rituximab 375 mg/m.

OUTCOMES

The patient evolved with progressive neurological deterioration, regardless of the improvement on neuroimaging.

LESSONS

We described the diagnostic dilemma we faced with an elderly man with rapid cognitive impairment and a myriad of differential diagnoses, diagnosed with primary CNS diffuse large B-cell lymphoma with a lymphomatosis cerebri-like pattern.

Neuroradiological features of lymphomatosis cerebri: A systematic review of the English literature with a new case report

Lymphomatosis cerebri is a rare form of diffusely infiltrating primary central nervous system (CNS) lymphoma (PCNSL). The neuroradiological findings of lymphomatosis cerebri have not been adequately characterized, as the relevant literature consists only of case reports and small case series. The present study describes an unusual presentation of lymphomatosis cerebri in a 56-year-old immunocompetent woman who presented with diffusely infiltrating lesions with perivascular curvilinear enhancement on initial magnetic resonance imaging (MRI) and multiple nodules on the later follow-up computed tomography (CT) scan. A systematic review of the literature is also performed searching PubMed between January 1996 and December 2016 to collect all pertinent case reports and series written in the English language with pathologically confirmed lymphomatosis cerebri and diffuse infiltrative PCNSL without cohesive masses on initial MRI. A total of 45 cases were identified from 39 articles and the present case report. The patient ages ranged from 28 to 85 years (mean, 57.3 years). Only 3 patients (6.7%) were immunosuppressed (acquired immune deficiency syndrome patients). The most common clinical presentation was cognitive changes or dementia (46.7%). Cerebrospinal fluid analysis in all cases was non-specific. Diffuse and asymmetric abnormal T2-hyperintensity in deep and subcortical white matter was observed in all cases. Gray matter involvement (17.8%), spreading along the corticospinal tract (35.6%) and a slight mass effect (51.1%) also were observed. Contrast-enhanced patterns on MRI could be divided into three forms of non-enhancement (64.4%) and non-mass-like enhancement (35.6%) on initial MRI, as well as nodular or mass-like enhancement on the later follow-up MRI (15.6%). There were non-specific findings on magnetic resonance spectroscopy for 4 patients, on positron emission tomography/CT for 12 patients and on single-photon emission CT for 1 patient. Diagnosis was established by brain biopsy in 35 cases (77.8%) and autopsy in 9 cases (20%), involving B-cell lymphoma in 40 cases (88.9%) and T-cell lymphoma in 4 cases (8.9%). In conclusion, lymphomatosis cerebri, namely diffuse PCNSL or diffuse lymphoma of the CNS, is characterized by rapidly progressive dementia in the elderly, diffusely infiltrated CNS white matter along the corticospinal tract, possible involvement of the gray matter, a slight mass effect and varied contrast-enhancement patterns on MRI. Non-enhancement or non-mass-like enhancement on MRI may be a special form of diffuse PCNL during disease development and progression.