Imaging of Lymphoma of the Central Nervous System, Spine, and Orbit

The Role of MRI in the Diagnosis of Spinal Cord Tumors

Spinal cord tumors are uncommon, and its multiple representatives not always have pathognomonic characteristics, which poses a challenge for both patients and caring physicians. The radiologist performs an important role in recognizing these tumors, as well as in differentiating between neoplastic and non-neoplastic processes, supporting clinical and surgical decision-making in patients with spinal cord injury. Magnetic Resonance Imaging (MRI) assessment, paired with a deep understanding of the various patterns of cord involvement allied to detailed clinical data can provide a diagnosis or significantly limit the differential diagnosis in most cases. In this article, we aim to review the most common and noteworthy intramedullary and extramedullary spinal tumors, as well as some other tumoral mimics, with an emphasis on their MRI morphologic characteristics.

Intradural Extramedullary Tumors and Associated Syndromes

Most intradural tumors are located within the intradural extramedullary compartment, and the most common tumors are schwannomas and meningiomas. Other less common neoplasms include neurofibroma, solitary fibrous tumor, myxopapillary ependymoma, lymphoma, metastatic leptomeningeal disease, malignant peripheral nerve sheath tumor, and paraganglioma. Patients usually present with gait ataxia, radicular pain, and motor and sensory deficits due to chronic compressive myelopathy or radiculopathy. MRI is the modality of choice for detecting and evaluating intradural extramedullary spinal tumors. This imaging technique helps narrow the differential diagnosis and therefore decide treatment.

Conventional and Advanced Imaging of Spinal Cord Tumors

Spinal cord tumors are best identified by conventional MR imaging with contrast. Most intramedullary spinal cord tumors have characteristic MR imaging features that allow an accurate preoperative diagnosis. The spinal cord tumors reviewed in this article include the most common tumors, ependymomas and astrocytomas, as well as the less common tumors such as hemangioblastomas and metastases. Rare tumors such as primary CNS lymphoma and melanocytic tumors are also described. Advanced imaging techqniques of more common intramedullary tumors are also reviewed.

B-Cell Lymphoma Intramedullary Tumor: Case Report and Systematic Review

Intramedullary tumors represent the major cause of spinal cord injuries, and its symptoms include pain and weakness. Progressive weakness may concomitantly occur in the upper and lower limbs, along with lack of balance, spine tenderness, sensory loss, trophic changes of extremity, hyperreflexia, and clonus. The study protocol was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A systematic search of the MEDLINE electronic database was performed to identify the studies reporting the clinical features of children and adults who presented with an intramedullary lymphoma. Twenty-one studies were included, reporting 25 cases. Manuscripts were excluded if the full-text article was not available, original data were not reported (e.g., review articles), or if the main disease was not intramedullary lymphoma. A structured data extraction form was employed to standardize the identification and retrieval of data from manuscripts. To enlighten the discussion, a case is also presented. An 82-year-old woman with Fitzpatrick skin type II, diagnosed and treated for non-Hodgkin's lymphoma 7 years ago, was admitted with mental confusion and memory loss for the past 2 months-evolving with recurring falls from her own height. One day before admission, she displayed Brown-Séquard syndrome. An expansive lesion from C2 to C4 in the cervical spinal cord was found and a hypersignal spinal cord adjacent was described at the bulb medullary transition to the C6-C7 level. A primary spinal cord tumor was considered, as well as a melanoma metastasis, due to the lesion's flame pattern. The patient presented a partial recovery of symptoms and a reduction of the spinal cord edema after being empirically treated with corticosteroids, but the lesion maintained its extent. Subsequently, a large diffuse B-cell lymphoma with nongerminal center was found in open body biopsy, infiltrating neural tissue. The main objective of the present study is to report a surgical case treated for a large diffuse B-cell lymphoma, in addition to presenting the results of a systematic review of primary intramedullary spinal cord lymphoma.

Non-Hodgkin Lymphoma Imaging Spectrum in Children, Adolescents, and Young Adults

In children, adolescents, and young adults (CAYA), non-Hodgkin lymphoma (NHL) is characterized by various age-related dissimilarities in tumor aggressiveness, prevailing pathologic subtypes, and imaging features, as well as potentially different treatment outcomes. Understanding the imaging spectrum of NHL in CAYA with particular attention to children and adolescents is critical for radiologists to support the clinical decision making by the treating physicians and other health care practitioners. The authors discuss the currently performed imaging modalities including radiography, US, CT, MRI, and PET in the diagnosis, staging, and assessment of the treatment response. Familiarity with diagnostic imaging challenges during image acquisition, processing, and interpretation is required when managing patients with NHL. The authors describe potentially problematic and life-threatening scenarios that require prompt management. Moreover, the authors address the unprecedented urge to understand the imaging patterns of possible treatment-related complications of the therapeutic agents used in NHL clinical trials and in practice. Online supplemental material is available for this article. ^©RSNA, 2022.

A Conservative Approach to the Treatment of a Rare Case of Cervical Spine Double Expressor Diffuse Large B-cell Lymphoma: A Case Report

Non-Hodgkin's lymphomas are a group of lymphoid neoplasms, with diffuse large B-cell lymphoma (DLBCL) being the most common subtype. Genetic alterations involving c-MYC, BCL-2, and BCL-6 have been implicated in the pathogenesis of subtypes of DLBCL with poor prognostic implications. This case report demonstrates a retropharyngeal mass with extension through the bilateral neuroforamina into the epidural space and posterior elements of the cervical spine (C2-C3), for which biopsy revealed diffuse large B-cell lymphoma. Here we present a unique case as it provides a solution for the dilemma on how to treat a patient with a known prior malignancy (gastrointestinal [GI] melanoma) with a retropharyngeal mass with epidural extension (dumbbell-shaped tumor) with an inconclusive initial CT-guided needle-core biopsy. A CT-guided biopsy only yielded that the mass was neoplasm; we had a choice between attempting gross total resection of the mass or open biopsy. Attempting gross total resection would have entailed an anterior approach (transoral with possible odontoidectomy or endoscopic endonasal with possible odontoidectomy) along with posterior instrumentation and fusion from occiput to C3, which is a rather morbid procedure that would subject the patient to a decreased quality of life as well as risks of vascular injury, dysphagia, and infection. We elected to perform an open biopsy of the epidural component of the mass through a decompressive laminectomy, which allowed for decompression of the spinal cord as well as a sampling of the mass. This provided treatment for possible increasing epidural compression from the mass, as well as diagnostic tissue. A multidisciplinary team discussed the case and developed a treatment plan for the patient with systemic and intrathecal chemotherapy in combination with radiotherapy. 

Traditional and Advanced Neuroimaging Contributions to the Diagnosis and Differential Diagnosis of Central Nervous System Lymphoma Patients Visiting a Comprehensive Medical Center

Introduction:

The diagnosis of Central Nervous System Lymphoma, especially the Primary Central Nervous System Lymphoma is carried out based on brain imaging, thus avoiding an unnecessary extend of surgery. But the traditional imaging techniques, such as Computed Tomography and Magnetic Resonance Imaging, were not satisfactory.

Aims:

This study was conducted to characterize the spectrum of advanced Neuroimaging, such as the advanced Magnetic Resonance Imaging features in the Central Nervous System Lymphoma patients in a comprehensive medical center in Lebanon, and compare them to what has been described in the literature review.

Methods:

It is a retrospective exploratory study of the clinical data and imaging features for patients admitted to the emergency and radiology departments with ages above 10 years, and who were diagnosed histopathologically with intracranial lymphoma. This study may be the first to make a Radiological evaluation of Central Nervous System Lymphoma on the local population of patients over 9 years .

Results:

Results showed that the study of the Computed Tomography and Magnetic Resonance Imaging data of 10 immunocompetent patients with Central Nervous System Lymphoma concurs with the previously described patient populations, except for the gender parameter. Tumors were mostly presented in the fifth or Sixth decade and they could be solitary or multi-focal. Lesions were typically located Preprint submitted to The Open Neuroimaging Journal May 14, 2020 in the supratentorial compartment. On the brain Computed Tomography, the lesions were hyperdense, and in pre-contrast Magnetic Resonance images, the lesions appeared hypointense on T1 and hyperintense on T2-Weighted images, but hypointense with respect to the grey matter. The lesions were also surrounded with a mild to moderate edema as compared to other intracranial neoplasms, such as glioblastomas. Evaluation results showed that on post-contrast Magnetic Resonance images, the majority of lesions exhibited a homogeneous enhancement of 50%. Majority of the lesions also showed a less common heterogeneous ring-like enhancement of 40%, and revealed the uncommon absence of enhancement of 10%. Calcifications, hemorrhage, and necrosis were rare findings and were present in only one patient.

Conclusion:

As a future prospect, studying whether the advanced imaging techniques may provide not only non-invasive and morphological characteristics but also non-invasive biological characteristics and thus accurate diagnosis could be considered.

Radiologic-Histopathologic Correlation of Adult Spinal Tumors: A Retrospective Study

Aim:

Preoperatively performed magnetic resonance images (MRIs) are essential before treating spinal tumors surgically. This study aims to investigate the compatibility of MRI preliminary diagnosis and proven histopathologic diagnosis of consecutively operated 96 spinal tumors.

Material and Methods:

Medical records were retrospectively reviewed for all spinal tumors operated at our institute during a period of 6 years. One hundred and ten spinal tumors were detected. Fourteen tumors were excluded because they were not met our study criteria.

Results:

Ninety-six cases of spinal tumors were detected in 46 female and 50 male patients. The mean age was 49.3 ± 22.7 years. The most common symptom was radicular pain (88.6%). Histopathologic diagnoses were metastasis (n = 26), meningioma (n = 16), schwannoma (n = 15), ependymoma (n = 9), astrocytoma (n = 6), chronic nonspecific granulomatous infection (n = 4), lymphoma (n = 3), lipoma (n = 3), epidural tuberculosis abscess (Pott's disease) (n = 3), and other pathologies in 11 cases. Cervical spine was the less spinal region affected with metastases (P < 0.05). Thoracic spine was the most affected spinal region from meningioma (P < 0.05). Preoperatively, preliminary diagnosis on MRIs was proven with histopathologic examinations in 22 metastasis, 14 meningioma, 11 schwannoma, and all epidermoid cyst and lipoma cases. Despite the fact that MRI cannot diagnose all cases of spinal tumors, MRIs had a high accurate rate to diagnose the most common spinal neoplasms (69.8%).

Conclusions:

Metastases rarely occurred in cervical spine, whereas meningiomas were most likely to occur in thoracic spine. MRIs can help diagnose metastases and spinal benign lesions, whereas they failed to distinguish astrocytomas and lymphomas. Further prospective studies with large size are needed to support our results.

Bone up on spinal osseous lesions: a case review series

Spinal osseous neoplasms are frequently encountered and can be challenging when present as solitary lesions. Familiarity with the range of benign and malignant spinal pathology can help the radiologist formulate a comprehensive differential diagnosis. This article focuses on the spectrum of extradural spinal tumors, accounting for the majority of primary spinal tumors, by comparing the epidemiology, pathophysiology, clinical presentation, and characteristic imaging appearance of these lesions. The discussion includes the commonly encountered benign lesions, such as vertebral venous vascular malformation and enostosis, as well as malignant lesions including metastases and lymphoma. The article also includes other less-encountered primary spinal tumors such as plasmacytoma, osteoid osteoma, osteoblastoma, giant cell tumor, eosinophilic granuloma, chordoma, chondrosarcoma, osteosarcoma, Ewing’s sarcoma, and angiosarcoma. Familiarity with the characteristic imaging features can help the radiologist reach an accurate diagnosis and obviate the need for unnecessary invasive procedures such as biopsy and surgery.

Intramedullary tumours and tumour mimics

Spinal cord lesions are traditionally classified as either extradural or intradural extramedullary or of intramedullary origin. Intramedullary spinal cord tumours are histopathologically similar to cranial tumours with a diverse range of pathologies. Astrocytomas and ependymomas account for approximately 80% of all intramedullary tumours, with other primary and secondary lesions accounting for the remaining 20%. Magnetic resonance imaging is the preferred imaging modality for diagnosing and characterising spinal cord lesions; however, accurate characterisation of tumour histology can be challenging, and is further confounded by intramedullary non-neoplastic lesions, such as demyelinating vascular, inflammatory, infectious, or traumatic lesions. This review illustrates the spectrum of intramedullary tumours and tumour mimics with emphasis on the imaging findings.

Multiple Neurologic Deficits and Cognitive Decline in a Young Woman

We present the clinicopathologic conference of a 34-year-old lady with history of facial palsy 14 years ago who developed new deficits of mononeuritis multiplex, maculopapular rash, pancytopenia, splenomegaly, lung involvement and cognitive decline rapidly over three years. Investigations revealed pancytopenia, reversal of albumin globulin ratio, mediastinal adenopathy, ANA positivity, low C3 levels with the CSF being inflammatory and MRI showing extensive hemorrhagic lesions with mass effect. She had a rapidly progressive fatal course over three years with the disease being undiagnosed. This case was presented in the annual meeting of the Indian Academy of Neurology in September 2018.

Primary spinal epidural diffuse large B-cell lymphoma with paraplegia as the first manifestation: a case report

Primary spinal epidural diffuse large B-cell lymphoma (DLBCL) is rare and often easily misdiagnose. Here, we presented a case of primary spinal epidural DLBCL with paraplegia as the first manifestation. He was misdiagnosed as thoracic disc herniation and thoracic tuberculosis successively. DLBCL was confirmed after surgery ultimately. After 6 cycles of chemotherapy with R-CHOPE, the patient went back to normal life without relapse during 2-year follow-up. Primary spinal epidural lymphoma should be suspected in patients with spinal cord compression with imaging showing isointense, homogeneous extradural contiguous level compressive soft‑tissue lesion without bony involvement and previous history of cancer.

Assessment of Primary Brain Lymphoma Using Multimodal Magnetic Resonance Imaging and Proton Magnetic Resonance Spectroscopy

Objectives:

The primary lymphoma of the central nervous system is a cancer rare. The diagnosis of this tumoral entity must be considered as an emergency considering the therapeutical involved. Therefore, we report this entity while reporting diagnostic challenges.

Patients and Methods:

Unfortunately, the conventional clinical and imaging signs can be confusing and might contribute to delay the diagnosis process of potentially curable pathological entity. The diagnosis confirmation in immunocompetent patients is based on a stereotaxic biopsy.

Results and Conclusion:

In this paper, we report a case illustrating the contribution of multimodal imaging including diffusion-weighted magnetic resonance imaging (MRI), diffusion tensor MRI, perfusion MRI, and proton MR spectroscopy to the diagnostic approach of the atypical primary lymphoma of the central nervous system.

Cerebellar large B-cell lymphoma: a case report

Background

Primary central nervous system lymphoma is a rare, malignant non-Hodgkin lymphoma that can arise in the brain, spinal cord, eye, leptomeninges, or cranial nerves. Primary central nervous system lymphoma is rare, accounting for 2–6% of all primary brain neoplasms and 1–2% of all non-Hodgkin lymphomas, and it usually presents as a solitary lesion. Cerebellar involvement is present in only 9% of cases. We present an unusual case of primary central nervous system lymphoma presenting as multiple lesions in the cerebellum in an immunocompetent host.

Case presentation

A 71-year-old Caucasian man presented to our hospital with acute onset of dizziness, nausea, vomiting, and gait imbalance. Contrast-enhanced computed tomography revealed three intensely enhancing masses in the right cerebellar hemisphere. Whole-body positron emission tomography and computed tomography failed to demonstrate a primary tumor of origin outside the central nervous system. The patient underwent right suboccipital craniotomy with partial resection of the visible tumor from the right cerebellum. Histopathology revealed diffuse large B-cell lymphoma, non-germinal center type.

Conclusions

Primary central nervous system lymphoma is rare, even more so in the cerebellum. However, the overall incidence of primary central nervous system lymphoma is rising in both immunocompromised and immunocompetent patients. The highly aggressive nature of primary central nervous system lymphoma necessitates timely diagnosis and intervention. In this report, we review the available literature for a better understanding of the pathophysiology and management of primary central nervous system lymphoma. To the best of our knowledge, this is the first reported case of a patient with primary central nervous system lymphoma presenting with multiple masses in the cerebellum.

Diagnosing Distensible Venous Malformations of the Orbit With Diffusion-weighted Magnetic Resonance Imaging

PURPOSE

To compare the diffusion-weighted imaging of nonthrombosed distensible venous malformations of the orbit with that of other histologically-proven orbital tumors.

DESIGN

Retrospective case-control study.

METHODS

Patients with nonthrombosed distensible venous malformations of the orbit and patients with other histologically-proven orbital tumors were selected for chart review. The main outcome measure was the apparent diffusion coefficient of these lesions.

RESULTS

Sixty-seven patients qualified for chart review; 9 patients had nonthrombosed distensible venous malformations and 58 patients had other histologically-proven tumors. Three of the 9 patients with nonthrombosed distensible venous malformations were initially misdiagnosed as having had solid orbital tumors. The mean apparent diffusion coefficient of distensible venous malformations was 2.80 ± 0.48 × 10^-3 mm²/s, whereas the mean apparent diffusion coefficient of other histologically-proven tumors was 1.18 ± 0.39 × 10^-3 mm²/s (P < .001). The mean apparent diffusion coefficient ranged from 2.42 to 3.94 × 10^-3 mm²/s in the distensible venous malformation group, whereas other histologically-proven tumors ranged from 0.53 to 2.08 × 10^-3 mm²/s. Therefore, in this single-institution series, a threshold value of 2.10 × 10^-3 mm²/s was 100% sensitive and 100% specific for distensible venous malformations.

CONCLUSION

Certain nonthrombosed distensible venous malformations can evade diagnostic suspicion and mimic solid orbital tumors on standard magnetic resonance imaging sequences. In this single-institution series, diffusion-weighted imaging effectively distinguished these nonthrombosed distensible venous malformations from other orbital tumors.

Primary central nervous system lymphoma in immunocompetent patients: spectrum of findings and differential characteristics

Primary central nervous system (CNS) lymphomas are uncommon and their management differs significantly from that of other malignant tumors involving the CNS. This article explains how the imaging findings often suggest the diagnosis early. The typical findings in immunocompetent patients consist of a supratentorial intraaxial mass that enhances homogeneously. Other findings to evaluate include multifocality and incomplete ring enhancement. The differential diagnosis of primary CNS lymphomas should consider mainly other malignant tumors of the CNS such as glioblastomas or metastases. Primary CNS lymphomas tend to have less edema and less mass effect; they also tend to spare the adjacent cortex. Necrosis, hemorrhage, and calcification are uncommon in primary CNS lymphomas. Although the findings in morphologic sequences are characteristic, they are not completely specific and atypical types are sometimes encountered. Advanced imaging techniques such as diffusion or especially perfusion provide qualitative and quantitative data that play an important role in differentiating primary CNS lymphomas from other brain tumors.

Neuroimaging in Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare aggressive high-grade type of extranodal lymphoma. PCNSL can have a variable imaging appearance and can mimic other brain disorders such as encephalitis, demyelination, and stroke. In addition to PCNSL, the CNS can be secondarily involved by systemic lymphoma. Computed tomography and conventional MRI are the initial imaging modalities to evaluate these lesions. Recently, however, advanced MRI techniques are more often used in an effort to narrow the differential diagnosis and potentially inform diagnostic and therapeutic decisions.

Primary diffuse large B-cell lymphoma of the central nervous system: A case report and literature review

The present study reports the clinical diagnosis and management of a patient with primary diffuse large B-cell lymphoma (Bcl) of the central nervous system (CNS). Making an early diagnosis of primary diffuse large Bcl is challenging due to the variable and complicated clinical manifestations of the disease. The relevant literature was reviewed, and high-dose methotrexate, whole brain radiotherapy and highly active antiretroviral therapy was recommended for the patient. The present study elucidates the role of positron emission tomography-computed tomography scans for the diagnosis and management of primary diffuse large Bcl of the CNS, and demonstrates the importance of resection surgery in the management of the disease. Specifically, the present study proposes that resection surgery may be applied in the early stages of disease for patients with a single occupied lesion and increased intracranial pressure.

MAGNETIC RESONANCE IMAGING FINDINGS IN THE SPINE OF SIX DOGS DIAGNOSED WITH LYMPHOMA

Lymphoma is one of the most common neoplasms in the dog. Despite its prevalence and the increasing use of advanced diagnostic imaging in veterinary patients only few reports of magnetic resonance imaging (MRI) findings in spinal lymphoma have been published to date. The purpose of this retrospective case series study was to describe the MRI findings in dogs with confirmed lymphoma affecting the spine and/or paraspinal soft tissues. Medical records were searched for patients that had MRI of the spine and a diagnosis of lymphoma during the period of 2005-2015. Data recorded from retrieved MRI studies were presence of focal or multifocal disease, structures involved, and signal characteristics on T2-W, short tau inversion recovery (STIR), and T1-W sequences prior to and following intravenous contrast medium administration. Six dogs met the inclusion criteria. Common findings included multifocal disease (4/6), vertebral involvement (5/6), spinal cord compression (4/6), and involvement of more than one spinal compartment (medullary cavity, vertebral canal, paraspinal soft tissues) (6/6). Vertebral changes were confined to the medullary cavity without evidence of cortical osteolysis. There was questionable involvement of the spinal cord in one case. All spinal and paraspinal lesions identified were T2-W isointense to hyperintense, STIR hyperintense, T1-W hypointense to isointense, and showed variable moderate to strong contrast enhancement. Additional lesions identified were enlarged intraabdominal lymph nodes, hepatomegaly, splenomegaly, and a splenic nodule. The STIR and T1-W postcontrast sequences were subjectively the most useful in identification of the spinal and paraspinal lesions.

Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence.

This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.

Primary Non-Hodgkin's Lymphoma of the Spine: A Case Report and Literature Review

Primary non-Hodgkin’s lymphoma (NHL) of the spine is a rare form of extranodal lymphoma. This entity constitutes a diagnostic challenge due to its mimicking of other spinal diseases and the difficulty in establishing a tissue diagnosis. In fact, core biopsy can be inconclusive, oftentimes requiring surgical biopsy. Definitive evidence is lacking regarding the treatment of choice. As a result, the prognosis remains unfavorable. We present the case of an adult female who presented with back pain and was found to have a spinal NHL. We also review the literature regarding this rare occurrence.

Ophthalmic manifestations of systemic diseases--part 1: phakomatoses, hematologic malignancies, metastases, and histiocytosis

The orbit can be secondarily involved in various systemic conditions. The ophthalmic involvement is often the first clue to the presence of an underlying systemic condition. The ophthalmic involvement in systemic diseases can be either ocular or extraocular. The extent of involvement can be well delineated by imaging modalities like computed tomography and magnetic resonance imaging. In the first part of the article, we provide an overview of systemic diseases affecting the orbit, briefly discuss the modalities for orbital imaging, and discuss the imaging appearances of ophthalmic involvement in (1) phakomatoses, (2) hematologic malignancies, (3) metastases, and (4) histiocytosis. At the end of the 2-part article, we discuss a pattern-based approach and differential diagnosis of orbital lesions in systemic diseases.

Diagnosis and treatment of primary central nervous system lymphoma: A report of nine cases and literature review

Primary central nervous system lymphoma (PCNSL) is a rare, highly malignant tumor type of the nervous system and is associated with poor prognosis. To investigate the efficacy of current treatment strategies for PCNSL, the present study retrospectively analyzed the clinical and pathological features, imaging results, clinical management, and prognoses of nine patients with PCNSL. Postoperative pathological examination confirmed a diagnosis of lymphoma in all the patients and the adopted treatment regimens were as follows: Stereotactic biopsy in combination with methylprednisolone (MP) and methotrexate (MTX) and/or radiotherapy; craniotomy in combination with dexamethasone or MP and/or radiotherapy; and neuroendoscopic surgery in combination with MP and MTX. The follow-up period was 5-27 months with an average duration of 10.1 months. After the initial three months of follow-up, the clinical symptoms of all the patients were significantly improved, with the tumor disappearing in seven patients and evidently reducing in size in two patients. However, six patients exhibited tumor recurrence, three of whom eventually succumbed to the disease during the follow-up period. Currently, comprehensive treatment strategies based on a combination of stereotactic biopsy, chemotherapy and radiotherapy are recommended for the treatment of PCNSL. However, the effectiveness of these treatments remains unsatisfactory. Thus, future studies are required to investigate methods for improving the efficacy of PCNSL treatment strategies.

Squash cytology of primary central nervous system lymphoma in an immunocompetent patient

The diagnosis of primary central nervous system lymphoma (PCNSL) can be suggested by magnetic resonance imaging (MRI). Cerebral PCNSL in immunocompetent patients generally shows marked homogeneous contrast enhancement in MRI. However, confirmation of it requires demonstration of lymphoma cells in stereotactic biopsy of the lesion or in cerebrospinal fluid. In the present case, with radiologic diagnosis of glioma, complete resection of the lesion by micro-neurosurgical technique was performed. The tumor tissue was examined by squash smear, frozen section and paraffin sections. Cytologic appreciation of tumor cells as lymphoid origin in squash smears negated the other possibilities. The immunocytochemistry on squash smear and immunohistochemistry on paraffin sections confirmed the diagnosis of diffuse large B cell lymphoma of non-germinal center B cell phenotype.

Imaging of adult ocular and orbital pathology--a pictorial review

Orbital pathology often presents a diagnostic challenge to the reporting radiologist. The aetiology is protean, and clinical input is therefore often necessary to narrow the differential diagnosis. With this manuscript, we provide a pictorial review of adult ocular and orbital pathology.

Intradural spinal tumours and their mimics: a review of radiographic features

Intradural spinal tumours, although relatively uncommon, can be diagnostically challenging, and often result in significant morbidity. They can be subdivided according to their cell of origin and whether they are within the cord (intramedullary) or intradural but extramedullary in location. The differential diagnosis for masses of the cauda equina region is often considered separately. Additionally, some inflammatory processes, cysts, benign tumour-like masses and vascular malformations may mimic intradural tumours. Although in many instances, a precise preoperative diagnosis is not possible as many of the imaging findings overlap, some features may strongly suggest one diagnosis over others. This article reviews the range of intradural spinal tumours in the adult and paediatric populations, with an emphasis on pertinent imaging characteristics. An approach is provided for distinguishing tumours from lesions that mimic tumours and for narrowing the differential diagnosis according to imaging findings.

Imaging of extranodal lymphoma with PET/CT

Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) represent a spectrum of malignant neoplasms arising from the lymphoid system with an incidence of around 8% of all malignancies. Although they are generally known as tumors of lymph nodes, 25% to 40% of HD/NHL tumors, especially NHL, arise at extranodal sites along the gastrointestinal tract, head and neck, orbit, central and peripheral nervous system, thorax, bone, skin, breast, testis, thyroid, and genitourinary tract. Extranodal involvement is an important pretreatment prognostic factor for patients with lymphoma and its incidence has increased in the past 2 decades. Imaging plays an important role in the noninvasive pretreatment assessment of patients with extranodal lymphoma. This involvement can be subtle and may be overlooked during computed tomography (CT). Positron emission tomography/CT (PET/CT) has evolved into an important imaging tool for evaluation of lymphomas, facilitating the detection of affected extranodal sites even when CT shows subtle or no obvious lesions. Familiarity with extranodal manifestations and suggestive PET/CT features in different sites is important for accurate evaluation of lymphoma. This article reviews the extranodal PET/CT imaging findings regarding HD and NHL.

Diffusion MR imaging for monitoring treatment response

The objective of this article was to emphasize the use of diffusion-weighted imaging in the diagnosis and follow-up of several major disease contexts, as established in recent literature. In some of these diseases the diffusion changes are correlated with the clinical deficit and are potentially useful for early diagnosis and longitudinal evaluation, as well as in the context of pharmacologic trials. Diffusion magnetic resonance is a major advance in the continuing evolution of MR imaging. It provides contrasts and characterization between tissues at a cellular level that may imply differences in function as well as framework and have contributed to a better understanding of the pathophysiological mechanisms of several diseases.

Primary intramedullary histiocytic sarcoma

Intramedullary primary central nervous system lymphoma (PCNSL) is a rare central nervous system (CNS) malignancy affecting mostly the brain, but it may also involve the leptomeninges, eyes, and spinal cord. A 71-year-old woman presented with back pain and progressive unilateral lower extremity weakness owing to an intramedullary primary histiocytic sarcoma of the spine, a rare PCNSL subtype. To the authors' knowledge, this is the first case of an intramedullary PCNSL caused by histiocytic sarcoma.

Ocular adnexal lymphoma: diffusion-weighted mr imaging for differential diagnosis and therapeutic monitoring

PURPOSE

To describe the magnetic resonance (MR) imaging and diffusion-weighted (DW) imaging features of ocular adnexal lymphomas (OALs), to determine the diagnostic accuracy of apparent diffusion coefficient (ADC) for discriminating OALs from other orbital mass lesions, and to assess whether variations in ADC constitute a reliable biomarker of OAL response to therapy.

MATERIALS AND METHODS

Institutional ethical committee approval and informed consent were obtained. In this prospective study, 114 white subjects (65 females and 49 males) were enrolled. Thirty-eight patients with histopathologically proved OAL underwent serial MR and DW imaging examination of the orbits. ADCs of OALs were compared with those of normal orbital structures, obtained in 18 healthy volunteers, and other orbital mass lesions, prospectively acquired in 58 patients (20 primary non-OAL neoplasms, 15 vascular benign lesions, 12 inflammatory lesions, 11 metastases). Interval change in ADC of OALs before and after treatment was analyzed in 29 patients. Analysis of covariance and a paired t test were used for statistical analysis.

RESULTS

Baseline ADCs in OALs were lower than those in normal structures and other orbital diseases (P < .001). An ADC threshold of 775 x 10(-6) mm(2)/sec resulted in 96% sensitivity, 93% specificity, 88% positive predictive value, 98.2% negative predictive value, and 94.4% accuracy in OAL diagnosis. Following appropriate treatment, 10 (34%) of 29 patients showed OAL volumetric reduction, accompanied (n = 7) or preceded (n = 3) by an increase in ADC (P = .005). Conversely, a further reduction of ADC was observed in the seven patients who experienced disease progression (P < .05).

CONCLUSION

ADC permits accurate diagnosis of OALs. Interval change in ADC after therapy represents a helpful tool for predicting therapeutic response.

FDG PET/CT of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease

The term extranodal disease refers to lymphomatous infiltration of anatomic sites other than the lymph nodes. Almost any organ can be affected by lymphoma, with the most common extranodal sites of involvement being the stomach, spleen, Waldeyer ring, central nervous system, lung, bone, and skin. The prevalence of extranodal involvement in non-Hodgkin lymphoma and Hodgkin disease has increased in the past decade. The imaging characteristics of extranodal involvement can be subtle or absent at conventional computed tomography (CT). Imaging of tumor metabolism with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) has facilitated the identification of affected extranodal sites, even when CT has demonstrated no lesions. More recently, hybrid PET/CT has become the standard imaging modality for initial staging, follow-up, and treatment response assessment in patients with lymphoma and has proved superior to CT in these settings. Certain PET/CT patterns are suggestive of extranodal disease and can help differentiate tumor from normal physiologic FDG activity, particularly in the mucosal tissues, bone marrow, and organs of the gastrointestinal tract. Familiarity with the different extranodal manifestations in various locations is critical for correct image interpretation. In addition, a knowledge of the differences in FDG avidity among the histologic subtypes of lymphoma, appropriate timing of scanning after therapeutic interventions, and use of techniques to prevent brown fat uptake are essential for providing the oncologist with accurate information.

Primary central nervous system lymphoma: an update

PURPOSE OF REVIEW

The purpose of the present review is to present an overview of the recent findings in diagnostic procedures, treatment outcomes and biological advances in primary central nervous system lymphoma (PCNSL).

RECENT FINDINGS

Recent imaging techniques are helpful in the diagnosis of atypical presentations of PCNSL and are likely to represent useful tools for patient follow-up. Knowledge of the biology of PCNSL is still fragmentary, but an increasing amount of data support the biological specificity of this disease with the identification of specific molecular alterations in PCNSL and specific interactions of lymphoma cells with the CNS microenvironment. The origin of the malignant cell is still unknown. Improvement of the therapeutic results along with numerous phase II studies clearly highlight a few important issues that need to be unequivocally answered and stress the need for the development of multicentric comparative studies. Attempts to decrease treatment-related toxicity on the CNS without impacting the disease control are ongoing.

SUMMARY

The standard of care for PCNSL has definitively switched toward a curative objective. Considerable cooperative efforts are being made and will hopefully result in both a better understanding of the disease and significant therapeutic outcomes.