Primary central nervous system post-transplant lymphoproliferative disorders: the spectrum of imaging appearances and differential

Post-transplant lymphoproliferative disorders after allogeneic hematopoietic stem cell transplantation: a case report, meta-analysis, and systematic review

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLD) are rare but severe complications that occur after solid organ or allogeneic hematopoietic stem cell transplantations (allo-HSCT), with rapid progression and high mortality. Primary central nervous system (CNS)-PTLD are rarely recognized histo-pathologically. In addition, the diagnostic value of the Epstein-Barr virus (EBV) DNA copies in CNS-PTLD remains poorly understood.

OBJECTIVES

We herein report a case of monomorphic EBV-associated CNS-PTLD (diffuse large B-cell lymphoma, DLBCL) after allo-HSCT and perform a meta-analysis to assess the efficacy of PTLD treatment strategies in recent years.

METHODS

We present the case report covering clinical manifestations, diagnosis, treatment, and outcomes of a patient with primary CNS-PTLD. Additionally, we include a systematic review and meta-analysis of the clinical characteristics of 431 patients with PTLD after allo-HSCT. We evaluate the main treatment options and outcomes of PTLD management, including rituximab, chemotherapies, and autologous or human leukocyte antigen (HLA)-matched EBV-specific cytotoxic T lymphocyte infusion (EBV-CTLs)/donor lymphocyte infusion (DLI).

RESULTS

The meta-analysis revealed an overall response rate of 69.0% for rituximab alone (95% CI: 0.47-0.84), 45.0% for rituximab plus chemotherapies (95% CI: 0.15-0.80), and 91.0% for rituximab plus EBV-CTLs/DLI (95% CI: 0.83-0.96). The complete response (CR) rate after treatments for PTLD was 67.0% (95% CI: 0.56-0.77). Moreover, the 6-month and 1-year overall survival (OS) rate was 64.0% (95% CI: 0.31-0.87) and 49.0% (95% CI: 0.31-0.68), respectively.

CONCLUSIONS

This case highlighted the urgent need for effective, low-toxic treatment regimens for CNS-PTLD. Our meta-analysis suggested that rituximab combined with EBV-CTLs/DLI could be a favorable strategy for the management of PTLD after allo-HSCT.

Primary central nervous system lymphomas in immunocompromised patients require specific response criteria

PURPOSE

Immunosuppression is a well-established risk factor for primary central nervous system lymphomas (PCNSLs), which present in this context distinct radiological characteristics. Our aim was to describe the radiological evolution of treated PCNSL in immunocompromised patients and suggest adapted MRI response criteria.

METHODS

We conducted a multicenter retrospective study of patients from the French LOC, K-Virogref and CANCERVIH network databases and enrolled adult immunocompromised patients with newly diagnosed PCNSL.

RESULTS

We evaluated the baseline, intermediate, end-of-treatment and follow-up MRI data of 31 patients (9 living with HIV, 16 with solid organ transplantation and 6 with an autoimmune disease under chronic immunosuppressive therapy). At baseline, 23/30 (77%) patients had necrotic lesions with ring enhancement and 28% of the lesions were hemorrhagic. At the end of the first-line treatment, 12/28 (43%) patients could not be classified according to the IPCG criteria. Thirteen of 28 (46%) patients still harbored contrast enhancement, and 11/28 (39%) patients had persistent large necrotic lesions with a median diameter of 15 mm. These aspects were not associated with a pejorative outcome and progressively diminished during follow-up. Six patients relapsed; however, we failed to identify any neuroimaging risk factors on the end-of-treatment MRI.

CONCLUSION

In immunocompromised patients, PCNSLs often harbor alarming features on end-of-treatment MRI, with persistent contrast-enhanced lesions frequently observed. However, these aspects seemed to be related to the necrotic and hemorrhagic nature of the lesions and were not predictive of a pejorative outcome. Specific response criteria for this population are thereby proposed.

Imaging Features of Immunodeficiency-Associated Primary CNS Lymphoma: A Review

In the immunocompromised setting, there are distinct radiologic findings of primary central nervous system lymphoma (PCNSL), including necrotic ring-enhancing lesions, increased propensity for intralesional haemorrhage, and multiplicity. In this clinical context, advanced imaging with MR perfusion, spectroscopy, and diffusion-weighted imaging can be used to increase accuracy in the diagnosis of lymphoma over mimics such as high-grade glioma, metastases, or infection. This review summarizes the histology and pathophysiology of PCNSL in immunodeficient hosts, which provide a basis for its imaging appearances, prognosis, and treatment. This discussion is important for the general radiologist as the incidence of immunodeficiency-related PCNSL may be increasing.

Primary central nervous system post-transplantation lymphoproliferative disorder: A case report and systematic review of imaging findings

Primary central nervous system post-transplant lymphoproliferative disease (PCNS-PTLD) is a rare subset of post-transplant lymphoproliferative disorder (PTLD) isolated to the CNS without nodal or extra-nodal organ involvement [1,2]. PCNS-PTLD occurs primarily in patients following either solid organ transplants or hematopoietic stem cell transplants and tends to be monomorphic DLBCL. The development of PCNS-PTLD is commonly associated with EBV infection [3]. Many intracranial pathologies can resemble the imaging appearance of PCNS-PTLD, including primary CNS lymphoma, glial tumors, metastatic disease, and intracranial abscesses. The purpose of this systematic review is to identify the most common imaging characteristics of PCNS-PTLD. Our review included 97 sources that describe the imaging appearance of PCNS-PTLD. Based on our review, PCNS-PTLD lesions are typically multifocal, ring-enhancing and diffusion-restricting. PCNS-PTLD lesions typically demonstrate focal FDG avidity. Despite advancement in medical imaging, PCNS-PTLD remains a diagnostic challenge due to its rare incidence. Limited data is available on advanced imaging with regards to PTLD, but techniques including DCE-MRI and fMRI demonstrate promising results that may help further delineate PCNS-PTLD.

A disease warranting attention from neurosurgeons: primary central nervous system post-transplant lymphoproliferative disorder

Background

Primary central nervous system post-transplant lymphoproliferative disorder (PCNS-PTLD) is a rare condition, posing diagnostic and treatment challenges, with histological biopsy essential for diagnosis. Standardized treatment protocols are lacking. This disease requires urgent attention due to the increasing number of organ transplant surgeries and the use of immunosuppressive agents.

Methods

From 2020 to 2023, our center diagnosed five patients with PCNS-PTLD. We reviewed their clinical records and conducted a comprehensive analysis of 22 literatures on PCNS-PTLD cases following renal transplantation or allogeneic hematopoietic stem cell transplantation (HSCT).

Results

Four patients had previously received a kidney transplant, one had undergone allogeneic HSCT. The median time from the last transplant surgery to the diagnosis of PCNS-PTLD differs between kidney transplant (21.5 years) and allogeneic HSCT (9 months). Common symptoms included motor weakness (n = 4), headache (n = 2), confusion (n = 2), and nausea (n = 2), with ring-enhancing (n = 5), typically solitary (n = 3) and supratentorial (n = 3) lesions on imaging. Diagnosis involved robot-assisted stereotactic brain biopsy (n = 4) or craniotomy (n = 1), all showing Epstein-Barr virus and CD20 positivity. Most cases (n = 4) were monomorphic diffuse large B-cell lymphoma. Treatment included rituximab (n = 3), surgical resection (n = 2), zanubrutinib (n = 1), whole-brain radiation (n = 1), and methotrexate (n = 1). At the last follow-up, the median duration of follow-up for all patients was 19 months. During this time, 3 patients had died and 2 patients were still alive.

Conclusion

In patients with a history of kidney transplantation or allogeneic HSCT who are on long-term immunosuppressive therapy, any neurological symptoms, particularly the presence of supratentorial ring-enhancing masses in the brain on imaging, whether solitary or multiple, should raise high suspicion for this disease, warranting a timely brain biopsy. Additionally, we found that besides reducing immunosuppressants, zanubrutinib may be a potential, safe, and effective treatment for this condition. Moreover, post-surgical administration of rituximab in conjunction with whole-brain radiotherapy also appears to be a potentially safe and effective approach.

Neuroimaging features of primary central nervous system post-transplantation lymphoproliferative disorder following hematopoietic stem cell transplant in patients with β-thalassemia: a case series and review of literature

PURPOSE

Primary central nervous system post-transplantation lymphoproliferative disorder (PCNS-PTLD) is a rare but serious complication of hematopoietic stem cell transplantation (HSCT) in patients with severe β-thalassemia. This study aimed to assess the clinical presentation, pathological characteristics, neuroimaging findings, and treatment strategies in patients with β-thalassemia who developed PCNS-PTLD and to compare a case series from our transplant center to reported cases from literature.

METHODS

We retrospectively reviewed our hospital database and identified four cases of pathologically confirmed PCNS-PTLD without a history of systemic PTLD in patients with severe β-thalassemia after HSCT. We also performed a relevant literature review on PCNS-PTLD.

RESULTS

The median time from transplantation to diagnosis of PCNS-PTLD was 5.5 months. Intracerebral lesions were usually multiple involving both supratentorial and infratentorial regions with homogeneous or rim enhancement. All patients had pathologically confirmed PCNS-PTLD with three patients having diffuse large B-cell lymphoma and the fourth patient having plasmacytic hyperplasia. There was low response to treatment with a median survival of 83 days.

CONCLUSION

PCNS-PTLD should be considered in the differential diagnosis of patients with β-thalassemia who had an intracranial lesion on neuroimaging after HSCT.

CRITICAL RELEVANCE STATEMENT

This case series with a comprehensive review of neuroimaging and clinical characteristics of children with primary central nervous system post-transplantation lymphoproliferative disorder should advance our understanding and improve management of this rare yet severe complication following transplant for β-thalassemia.

KEY POINTS

• We assessed clinical presentation, treatment strategies, and neuroimaging characteristics of PCNS-PTLD in patients with β-thalassemia after transplantation. • Patients with β-thalassemia may have post-transplantation lymphoproliferative disorder presenting as brain lesions on neuroimaging. • Neuroimaging findings of the brain lesions are helpful for prompt diagnosis and proper management.

Diagnostic, Pathologic, and Therapeutic Considerations for Primary CNS Lymphoma

Primary CNS lymphoma (PCNSL) is a rare lymphoma representing 3% of CNS malignancies. The diagnosis is complicated by the unique risks associated with brain biopsy, and the treatment is similarly complicated by the restriction of effective therapeutics able to cross the blood-brain barrier. Currently, the majority of individuals diagnosed with this disease are immunocompetent although immune deficiency related to HIV or immunosuppressive therapy remains an important risk factor. Improvements in both frontline therapy and consolidation options, including the use of hematopoietic stem-cell transplantation, have translated to improved survival. Unfortunately, patients experiencing relapsed or refractory disease often fare poorly. Here, we review key clinical, pathologic, and therapeutic aspects of PCNSL and highlight challenging clinical scenarios that may be encountered by the treating oncologist.

Post-transplant lymphoproliferative disorder myeloradiculopathy

A 56-year-old woman developed progressive subacute lower limb weakness with sensory and autonomic abnormalities. She had received a living-donor kidney transplantation 21 years before for end-stage chronic kidney disease and took mycophenolate mofetil and prednisolone. MR scan of the spinal cord showed bilateral cauda equina gadolinium enhancement and MR scan of the brain showed enhancing nodular hyperintensities in the internal capsule and globus pallidus. Cerebrospinal fluid (CSF) showed a pleocytosis with extremely low glucose, and positive DNA-PCR for Epstein-Barr virus. Her condition worsened despite empirically guided antimicrobial treatment. CSF immunophenotyping later identified mature, clonal B lymphocytes of large size, expressing CD19, CD20, CD200 antigens, and kappa light chain immunoglobulin, with absent CD5 and CD10 expression. We diagnosed a myeloradiculopathy from a monomorphic post-transplant lymphoproliferative disorder. This condition occurs after kidney transplantation and falls on the lymphoma spectrum. We review its clinical features, diagnosis and management.

Successful Treatment of Central Nervous System Post-Transplant Lymphoproliferative Disease With a Reduced Dose of High-Dose Methotrexate

Post-transplant lymphoproliferative disease (PTLD) is a complication of solid organ and hematopoietic stem cell transplantation that occurs as a result of immunosuppression. PTLD isolated to the central nervous system (CNS) is a rare disease and it presents with nonspecific signs and symptoms. Optimal therapy guidelines have not yet been established for CNS PTLD. Here, we report a case of successful treatment of CNS PTLD in an adult female following two subsequent kidney transplants. Initial management was with immunosuppression reduction and a trial of rituximab. There were concerns regarding using methotrexate (MTX) given the patient's fragile transplant status. Magnetic resonance imaging of the brain following four cycles of rituximab revealed the progression of the disease. Subsequently, high-dose MTX (HD-MTX) was considered within the constraints of potential kidney toxicities given her transplant status and chronic kidney disease. Potential toxicities from other therapies, such as brain radiation, also factored into the final decision. The patient was treated with one cycle of a combination of rituximab and HD-MTX 1 g/m². The patient tolerated HD-MTX and did not have evidence of renal toxicity in laboratory studies. Following that, she was started on a reduced dose of HD-MTX at 2 g/m² every two weeks instead of the higher MTX dose range of 3.5 to 8 g/m², which was a shared decision with the patient and nephrology after weighing the risk of kidney dysfunction with the possibility of a less than optimal response with regards to her lymphoma. She was followed with a magnetic resonance imaging of the brain, which demonstrated a complete response after four cycles. Further consolidation treatments with HD-MTX 2 g/m² every four weeks were administered to complete one year of treatment. Following the completion of chemotherapy, the patient was able to achieve and maintain a complete response without affecting her kidney function. She continues to do well one year following treatment. This case highlights the significance of tailoring therapy to each individual based on their comorbidities and clinical response, as well as the possible merit in exploring the use of a reduced dose of HD-MTX in the treatment of CNS PTLD in patients at high risk for renal toxicity.

Post-Transplant Lymphoproliferative Disorder: A Rare Case of CNS Involvement following Renal Transplant

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLD) are rare immunosuppression complications affecting 5% of transplant patients. Isolated central nervous system (CNS)-PTLD without nodal or extra-nodal organ involvement is rarely reported and is difficult to diagnose due to the non-specific clinical manifestations and imaging features overlapping with other common CNS lesions.

CASE PRESENTATION

We present a case of a 72-year-old female subjected to a renal transplant 11 years ago with progressively worsening headaches and confusion. Imaging revealed vasogenic edema in the left frontal and bilateral temporal lobes. She was subjected to a craniotomy and excisional biopsy to obtain tissue for diagnostic and therapeutic interventions. Pathology examination showed atypical EBV-positive lymphoplasmacytic infiltrate, consistent with Polymorphic type PTLD.

CONCLUSIONS

Patients diagnosed with PTLD need to have close monitoring of immunosuppressive medications while in the hospital. Early diagnosis is essential for patient survival with PTLD, as their health can deteriorate fast.

Extremely delayed-onset post-transplant lymphoproliferative disorder in a renal transplant patient

Post-transplant lymphoproliferative disorder (PTLD) is a rare condition that occurs in patients who have undergone solid organ transplantation. Symptoms at presentation depend on the organs involved. PTLD most commonly occurs in the first year after transplant (early onset) or around 5 years after transplant (late onset). Herein, we report a rare presentation of central nervous system PTLD in an adult who presented with seizures 17 years after renal transplantation. After extensive infectious and transplant-related workup, brain biopsy confirmed the diagnosis of PTLD. The patient was treated with rituximab and high-dose methotrexate. Eighteen months later, the patient had no signs of recurrence. Very late-onset (>10 years) PTLD is rare, but is likely to become more common with more long-term survivors of solid organ transplant. Data are limited but show that the factors associated with very late-onset PTLD are different from early or late-onset PTLD.

Blood-Brain Barrier Alterations and Edema Formation in Different Brain Mass Lesions

Differential diagnosis of brain lesion pathologies is complex, but it is nevertheless crucial for appropriate clinical management. Advanced imaging methods, including diffusion-weighted imaging and apparent diffusion coefficient, can help discriminate between brain mass lesions such as glioblastoma, brain metastasis, brain abscesses as well as brain lymphomas. These pathologies are characterized by blood-brain barrier alterations and have been extensively studied. However, the changes in the blood-brain barrier that are observed around brain pathologies and that contribute to the development of vasogenic brain edema are not well described. Some infiltrative brain pathologies such as glioblastoma are characterized by glioma cell infiltration in the brain tissue around the tumor mass and thus affect the nature of the vasogenic edema. Interestingly, a common feature of primary and secondary brain tumors or tumor-like brain lesions characterized by vasogenic brain edema is the formation of various molecules that lead to alterations of tight junctions and result in blood-brain barrier damage. The resulting vasogenic edema, especially blood-brain barrier disruption, can be visualized using advanced magnetic resonance imaging techniques, such as diffusion-weighted imaging and apparent diffusion coefficient. This review presents a comprehensive overview of blood-brain barrier changes contributing to the development of vasogenic brain edema around glioblastoma, brain metastases, lymphomas, and abscesses.

Approach to Neurologic Complications in the Immunocompromised Patient

Neurologic complications are common in immunocompromised patients, including those with advanced human immunodeficiency virus, transplant recipients, and patients on immunomodulatory medications. In addition to the standard differential diagnosis, specific pathogens and other conditions unique to the immunocompromised state should be considered in the evaluation of neurologic complaints in this patient population. A thorough understanding of these considerations is critical to the inpatient neurologist in contemporary practice, as increasing numbers of patients are exposed to immunomodulatory therapies. In this review, we provide a chief complaint-based approach to the clinical presentations and diagnosis of both infectious and noninfectious complications particular to immunocompromised patients.

Central nervous system infections after solid organ transplantation

PURPOSE OF REVIEW

Significant advances to our understanding of several neuroinfectious complications after a solid organ transplant (SOT) have occurred in the last few years. Here, we review the central nervous system (CNS) infections that are relevant to SOT via a syndromic approach with a particular emphasis on recent updates in the field.

RECENT FINDINGS

A few key studies have advanced our understanding of the epidemiology and clinical characteristics of several CNS infections in SOT recipients. Risk factors for poor prognosis and protective effects of standard posttransplant prophylactic strategies have been better elucidated. Newer diagnostic modalities which have broad clinical applications like metagenomic next-generation sequencing, as well as those that help us better understand esoteric concepts of disease pathogenesis have been studied. Finally, several studies have provided newer insights into the treatment of these diseases.

SUMMARY

Recent findings reflect the steady progress in our understanding of CNS infections post SOT. They provide several avenues for improvement in the prevention, early recognition, and therapeutic outcomes of these diseases.

The spectrum of Epstein-Barr virus infections of the central nervous system after organ transplantation

BACKGROUND

Epstein-Barr virus (EBV)-related neurologic complications have a diverse presentation in transplant recipients, creating diagnostic and therapeutic challenges for clinicians. In this case series, we report unique manifestations of EBV related neurologic complications following solid organ transplant and highlight pitfalls in management.

CASE PRESENTATIONS

A retrospective search of the electronic medical record of all patients from January 2015 to December 2020 who underwent solid organ transplantation and had central nervous system complications as determined by ICD-10 codes were included. Three patients with unique manifestation of EBV-related neurologic complications after liver transplantation were identified. The first was a 52-year-old man with a live-donor liver transplant 11 years prior for Budd-Chiari syndrome presented with several weeks of headache and several lesions on brain MRI; he was diagnosed with primary central nervous system post-transplant lymphoproliferative disorder. The second patient was a 63-year-old man with a deceased-donor liver transplant 16 years prior for alpha-1-antitrypsin deficiency and was found to have a stroke; he was diagnosed with EBV encephalitis. The final patient was a 75-year-old woman with a deceased-donor liver transplant six years prior for primary biliary cirrhosis who presented with four months of gait instability; she was diagnosed with EBV myelitis. A review of the literature was performed to supplement description of the different diseases.

CONCLUSIONS

EBV-related central nervous infection in post-transplant patients can manifest in a variety of neurologic syndromes, which can be challenging to diagnose. Careful correlation of clinical, pathologic, and radiologic findings and a high index of suspicion are crucial in identification and appropriate management.

Successful treatment of central nervous system lymphoproliferative disorder in a kidney-pancreas and stem cell transplanted patient using intrathecal rituximab

Central nervous system lymphoproliferative disorder (CNS-PTLD) after organ transplant is a unique clinicopathological entity and is associated with poor survival rates. When the CNS is involved, intravenous rituximab might not be the treatment of choice, due to its poor CNS penetration. However, intrathecal (IT) administration of rituximab has shown to be safe and efficient in small studies and in case series. We report here the case of a patient with late development of CNS-PTLD after kidney-pancreas transplantation who achieved complete remission after surgical resection and four cycles of IT rituximab and we provide a review of the literature for this treatment option.

CNS Post-Transplant Lymphoproliferative Disorder in a Heart Recipient: A Case Report

Solid organ recipients have increased risk of malignancy in comparison with general population. Although post-transplant lymphoproliferative disorders are the second most common cancer in transplanted patients, primary CNS lymphoma is a rare presentation of these disorders. Among the wide range of neurologic complications in post- transplant period, some characteristics could be helpful for diagnosing of this disorder. Rarity of CNS lymphoma may lead to late diagnosis of this disease while early detection has utmost importance for better management of it. Here, we describe a heart recipient young woman with focal neurologic symptoms 14 months after transplantation and some features that could be helpful for on-time diagnosis.

Radiologic Differentiation of Primary CNS Posttransplant Lymphoproliferative Disorder From Brain Metastasis

OBJECTIVE. Primary CNS posttransplant lymphoproliferative disorder (PTLD) may present as multiple contrast-enhancing intraaxial lesions, often with central necrosis and surrounding edema. This imaging appearance is similar to the pattern seen in brain metastases. The purpose of this study was to find differences in the radiologic features of primary CNS PTLD lesions and brain metastases. MATERIALS AND METHODS. We retrospectively reviewed the radiologic findings of 51 primary CNS PTLD lesions in 10 patients and 156 metastatic brain lesions in 25 patients. Lesion size, multifocality, location, necrosis, hemorrhage, perilesional vasogenic edema, contrast enhancement, and diffusion and perfusion features were evaluated. We used the chi-square test or Fisher exact test when appropriate to compare the findings between primary CNS PTLD lesions and brain metastases. RESULTS. Primary CNS PTLD lesions occur in the deep gray matter and periventricular locations more frequently than brain metastases (p < 0.0001) and are not present at the gray and white matter junctions and vascular border zones as commonly as brain metastases are (p < 0.0001). Primary CNS PTLD tends to have less frequent hemorrhage (p < 0.0001), more restricted diffusion (p = 0.001), and lower perfusion (p = 0.002) than brain metastases. We did not find statistically significant differences between primary CNS PTLD and brain metastases for lesion size, multifocality, necrosis, and perilesional edema. CONCLUSION. The imaging characteristics of primary CNS PTLD overlap considerably with those of brain metastases, but there are significant differences between primary CNS PTLD lesions and brain metastases in lesion location, diffusion and perfusion features, and tendency to hemorrhage.

Intracranial peripherally enhancing lesions in cardiac transplant recipients: A rare case series and literature review

Intracranial peripherally enhancing lesions in immunosuppressed solid organ transplant recipients represent a unique diagnostic and management dilemma due to the vast array of differentials that demand consideration. Diagnosis of the underlying pathology is often guided by the use of magnetic resonance imaging (MRI). We present the first published case series of three cardiac transplant recipients with significantly atypical neuroradiological findings contrary to the tenets of contemporary literature. Our rare case series consists of: (1) A sterile Mycobacterium pyogenic abscess mimicking glioblastoma multiforme due to an immunosuppressed state (2) Epstein Barr Virus encephalitis masquerading as Central Nervous System Post-Transplant Lymphoproliferative Disorder (3) An unusual case of partially treated disseminated Nocardiosis warning of the need to consider the immunosuppressed state and partial treatment response obfuscating classical MRI appearances. We utilise these unprecedented cases as the basis of a literature review to understand the pathophysiology behind the peculiar imaging findings in this rarefied cohort of transplant recipients, and rationalise why the MRI findings in each instance contradicts the accepted imaging patterns. In the setting of potential unreliability of neuroradiology in this immunosuppressed unique subgroup, we hope to impart to clinicians that definitive diagnosis obtained by emergent neurosurgical intervention may be necessary to accurately and expediently guide further medical management.

Parkinsonism as a late presentation of lymphomatosis cerebri following high-dose chemotherapy with autologous stem cell transplantation for primary central nervous system lymphoma

Primary central nervous system lymphoma is an aggressive form of non-Hodgkin lymphoma arising in the eyes, meninges, spinal cord, or brain. Treatment of primary CNS lymphoma with a combination of high-dose chemotherapy and autologous stem cell transplantation has been shown to have high rates of remission which is frequently sustained for multiple years. Recurrence of primary CNS lymphoma generally presents with one or multiple contrast enhancing lesions on MRI. In rare cases, lymphoma cells may proliferate diffusely within the brain parenchyma without mass formation, a pattern termed lymphomatosis cerebri. Lymphomatosis cerebri presents a significant diagnostic challenge, and has not been reported to present with parkinsonism. Here, we present a case of initially mass forming, contrast-enhancing primary CNS lymphoma which remitted following chemotherapy and autologous stem cell transplantation, and recurred 7 years post-transplant with symptoms of parkinsonism and a lack of typical lesions on imaging, with lymphomatosis cerebri confirmed at autopsy.