OBJECTIVE: Primary central nervous system lymphoma (PCNSL) is a rare, aggressive form of extranodal non-Hodgkin lymphoma. To predict the overall survival (OS) in advance is of utmost importance as it has the potential to aid clinical decision-making. Though radiomics-based machine learning (ML) has demonstrated the promising performance in PCNSL, it demands large amounts of manual feature extraction efforts from magnetic resonance images beforehand. deep learning (DL) overcomes this limitation.
METHODS: In this paper, we tailored the 3D ResNet to predict the OS of patients with PCNSL. To overcome the limitation of data sparsity, we introduced data augmentation and transfer learning, and we evaluated the results using r stratified k-fold cross-validation. To explain the results of our model, gradient-weighted class activation mapping was applied.
RESULTS: We obtained the best performance (the standard error) on post-contrast T1-weighted (T1Gd)-area under curve [Formula: see text], accuracy [Formula: see text], precision [Formula: see text], recall [Formula: see text] and F1-score [Formula: see text], while compared with ML-based models on clinical data and radiomics data, respectively, further confirming the stability of our model. Also, we observed that PCNSL is a whole-brain disease and in the cases where the OS is less than 1 year, it is more difficult to distinguish the tumor boundary from the normal part of the brain, which is consistent with the clinical outcome.
CONCLUSIONS: All these findings indicate that T1Gd can improve prognosis predictions of patients with PCNSL. To the best of our knowledge, this is the first time to use DL to explain model patterns in OS classification of patients with PCNSL. Future work would involve collecting more data of patients with PCNSL, or additional retrospective studies on different patient populations with rare diseases, to further promote the clinical role of our model.

Primary Central Nervous System Lymphoma (PCNSL) is an aggressive neoplasm with a poor prognosis. Although therapeutic progresses have significantly improved Overall Survival (OS), a number of patients do not respond to HD-MTX-based chemotherapy (15-25%) or experience relapse (25-50%) after an initial response. The reasons underlying this poor response to therapy are unknown. Thus, there is an urgent need to develop improved predictive models for PCNSL. In this study, we investigated whether radiomics features can improve outcome prediction in patients with PCNSL. A total of 80 patients diagnosed with PCNSL were enrolled. A patient sub-group, with complete Magnetic Resonance Imaging (MRI) series, were selected for the stratification analysis. Following radiomics feature extraction and selection, different Machine Learning (ML) models were tested for OS and Progression-free Survival (PFS) prediction. To assess the stability of the selected features, images from 23 patients scanned at three different time points were used to compute the Interclass Correlation Coefficient (ICC) and to evaluate the reproducibility of each feature for both original and normalized images. Features extracted from Z-score normalized images were significantly more stable than those extracted from non-normalized images with an improvement of about 38% on average (p-value < 10-12). The area under the ROC curve (AUC) showed that radiomics-based prediction overcame prediction based on current clinical prognostic factors with an improvement of 23% for OS and 50% for PFS, respectively. These results indicate that radiomics features extracted from normalized MR images can improve prognosis stratification of PCNSL patients and pave the way for further study on its potential role to drive treatment choice.

Primary central nervous system lymphoma (PCNSL) is a rare brain tumor that most commonly arises in the cerebral white matter, basal ganglia, peri-ventricle or corpus callosum. Confinement of PCNSL to the third ventricle is extremely rare, and seldom presents with intratumoral hemorrhage (ITH). The present study described the case of a 75-year-old woman who presented with obstructive hydrocephalus due to third-ventricle PCNSL. On magnetic resonance imaging (MRI), the tumor presented ITH on T2*-weighted images and a highly elevated regional cerebral blood volume on dynamic susceptibility contrast-enhanced MRI (DSC-MRI). Due to the high elevation of the regional cerebral blood volume, high-grade glioma was suspected as a preoperative diagnosis. The patient underwent endoscopic tumor biopsy and third ventricle PCNSL was successfully diagnosed. The patient achieved good prognosis at an early stage after the start of treatment initiation. There are many differential considerations for a third-ventricle tumor, and DSC-MRI can help the differential diagnosis of these tumors. Furthermore, the presence of ITH can lead to the inaccurate estimation of regional cerebral blood volume values. Overall, silent or microhemorrhage in PCNSL may be underestimated, and clinicians should therefore carefully evaluate tumor vascularity by MRI.

BACKGROUND: Primary central nervous system diffuse large B-cell lymphoma (PCNSL) is an ominous disease with a poor prognosis. PCNSL is now known to be a form of extra-nodal, high-grade non-Hodgkin B-cell neoplasm, usually large cell or immunoblastic type.
OBJECTIVE: Sharing a rare case report of PCNSL and its diagnostic and therapeutic outcome.
METHODS: A case report.
METHODS: A 46-year-old woman was admitted in our clinic with a persistent frontal headache associated with dizziness, fatigue, and weakness. Brain MRI revealed a right frontal ganglia lesion, and a biopsy was performed on the site. The HP/Dg showed a right frontal lesion - diffuse large B-cell lymphoma, positive on CD20 with Ki-67: 90%. Since laboratory tests and physical examination findings were normal, we decided to immediately start treating our patient with rituximab-temozolomide protocol. After 6 rounds of chemotherapy, we repeated a brain MRI, and it revealed no pathological findings other than scars after the first surgery. Then, we decided to perform a PET-CT, which also revealed no pathological FDG absorption in the brain but two hypermetabolic zones in the liver with SUV-7.2. The following abdomen MRI revealed no pathological lesions in the liver, so we decided to continue with maintenance therapy with temozolomide for 8 months. Unfortunately, during the sixth round of maintenance therapy, the patient developed headaches, and repeated brain MRI revealed 35×30-mm lesions on the parasagittal frontal left hemisphere. We decided to treat with RMPV protocol. After 6 cycles of RMVP, a brain MRI revealed regression of lesions in both sides of frontal lobe, and the patient was stable for the 3 following months but was admitted again with a severe and worsening condition. MRI revealed an increased frontal lobe mass and we suggested to start a more aggressive chemotherapy approach with RMVP-ARA-C, but the patient did not survive to begin the treatment.
CONCLUSIONS: The initial response to chemotherapy was excellent, but considering the aggressive nature of the tumor, the duration of response remained short. Methotrexate-based chemotherapy markedly improves survival, but it unfortunately did not in our patient.

UNASSIGNED: Primary central nervous system lymphoma (PCNSL) is a rare tumor with a poor prognosis. Early brain biopsy is essential to avoid a diagnostic delay. To date, reports of successful diagnosis for PCNSL of the corpus callosum by endoscopic biopsy are rare.
METHODS: Herein, we report the case of an elderly woman with PCNSL of the corpus callosum who initially presented with rapidly progressive dementia. The condition was finally diagnosed by microscopic biopsy after unsuccessful endoscopic biopsy. Moreover, the postoperative course was uneventful. She is currently receiving systemic chemotherapy.
UNASSIGNED: Early diagnosis and subsequent systemic chemotherapy with or without whole brain radiotherapy are critical for PCNSL. Endoscopic biopsy may be a diagnostic option for suspected PCNSL, although stereotactic needle biopsy is most commonly used.
CONCLUSIONS: Utilizing neuronavigation and 5-aminolevulinic acid (ALA) fluorescence guidance could be helpful in identifying lesions insufficiently exposed by endoscopic visualization. However, cerebrospinal fluid (CSF) loss due to the endoscopic approach through the ventricle might be a cause of neuronavigation misregistration.

Primary central nervous system lymphoma (PCNSL) is a rare form of CNS tumor. Immunosuppression is the most important risk factor of PCNSL, but few immunocompetent individuals are also affected. The most common clinical feature of PCNSL includes dizziness and ataxia. Our patient was a 71-year-old immunocompetent female who presented with progressive ataxia, imbalance, and dizziness for one year. A homogenous enhancing lesion was found in magnetic resonance imaging (MRI) of the head. One month later, on a follow-up MRI, a significant increase in the tumor size with surrounding edema was seen. The patient underwent craniotomy and resection of the mass. Subsequently, a diagnosis of diffuse large B cell lymphoma was made on pathology examination. Guideline-directed treatment options were discussed. This case highlights that the prognosis of patients with PCNSL highly depends on the factors such as age and physical status. Early diagnosis by accurate interpretation of imaging and management is crucial for better health outcomes.

Primary central nervous system lymphoma (PCNSL) is a rare intracranial neoplasm in older adults. Tumor-associated parkinsonism (TAP) in PCNSL is extremely rare, and its clinical features are unclear. The present report describes the case of a 75-year-old man who presented with parkinsonism due to multiple hyperintense lesions in the thalamus and periventricular white matter as visualized by magnetic resonance imaging (MRI). Due to the rapid progression of parkinsonism and lesion enlargement, the patient underwent stereotaxic biopsy. Subsequently, his condition was diagnosed as TAP in PCNSL at 2 months after onset. The patient completely recovered after treatment and experienced no recurrence of TAP for 8 months. Although it is difficult to distinguish TAP from vascular parkinsonism (VP) at initial consultation, the early diagnosis of PCNSL is important for improving prognosis. In the case of rapidly progressing parkinsonism, one should suspect the possibility of TAP associated with early-stage PCNSL. Early treatment improves the chances of remission and decreases the possibility of recurrence.

BACKGROUND: Primary central nervous system lymphoma is a rare extra-nodal lymphoma of the central nervous system. Primary central nervous system lymphoma lesions usually appear in the vicinity of the ventricle, and there are few reports of primary central nervous system lymphoma with hypothalamic-pituitary lesions.
METHODS: We treated a 56-year-old male with primary central nervous system lymphoma with the primary lesion in the hypothalamus, which was found by magnetic resonance imaging after sudden onset of endocrinological abnormalities. Initially, he was hospitalized to our department for hyponatremia. Endocrinological examination in conjunction with head magnetic resonance imaging and endoscopic biopsy revealed hypothalamic hypopituitarism and tertiary hypoadrenocorticism caused by a rapidly growing, diffuse large B-cell lymphoma in the hypothalamus. Remission of the tumor was achieved by high-dose methotrexate with whole brain radiotherapy, and some of the hormone responses were normalized.
CONCLUSIONS: While primary central nervous system lymphoma is rare, it is important to note that hypopituitarism can result and that the endocrinological abnormalities can be partially restored by its remission.

Introduction Mycophenolate Mofetil (MMF), although a widely used immunosuppressant; an increasing concern of MMF induced Primary Central Nervous System Lymphoma (PCNSL) are being reported. Timely diagnosis and management of MMF induced PCNSL can play a vital role in improved outcomes. Case Presentation Eighty-one-year-old female with history of Eosinophilic Granulomatosis with Polyangiitis (EGPA) presented with word finding difficulty, right-hand weakness and right foot clumsiness. EGPA had been stable with MMF for 6 years. Physical examination revealed weakened right-hand grip, positive right-sided dysdiadokokinesia and right foot drop. MRI-brain identified three enhancing solid lesions - in right parietal, left insular and left mid brain extending into the left thalamus. Brain biopsy revealed a focally dense lymphoid infiltrate with CD20 positive B cells, with large atypical cells resembling Hodgkin Reed-Sternberg cells. With concern for immunosuppression related PCNSL, MMF was stopped. Patient was treated with 8 weeks of rituximab therapy for its least toxic profile and concomitant benefit in EGPA. On a 2 month follow up MRI-brain, near total resolution of the intracranial lesion was observed. Patient still had some residual right lower extremity incoordination, however, strength and speech normalized with resolution of dysdiadokokinesia. Patient was advised to discontinue MMF indefinitely and remains on low dose prednisone daily. Conclusion MMF is an inhibitor of Inosine Monophosphate Dehydrogenase which prevents T- and B-cell proliferation. PCNSL is a potential complication of chronic immunosuppression with this medication. Discontinuation of the drug along with immunosuppressive therapies have been the effective therapeutic options till date.

Primary central nervous system lymphoma (PCNSL) is rare. And the symptoms of PCNSL are atypical, it is extremely easy to be misdiagnosed as other diseases. However, early treatment is crucial which is requesting early diagnosis. We report a case of a 47-year-old man who was initially diagnosed as neuromyelitis optica (NMO) on the basis of clinical findings, slightly high Aquaporin4 (AQP4) (1:10) and high signals of magnetic resonance imaging. Though his symptoms progressively improved after steroid pulse treatment, but worse when steroid was decreased to 40 mg per day. We considered the patient should be diagnosed as PCNSL. After the examination of magnetic resonance spectroscopy (MRS) and positron emission tomography (PET), the results indicated PCNSL was most possible. Therefore we gave him stereotactic biopsy of deep of supratentorial, which showed non-Hodgkin malignant B-cell lymphoma.