Sentinel Lesions Research Articles

10020-ML-1 SENTINEL LESION PRECEDING PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA

Abstract It has been reported that there are rare cases of spontaneous resolution, which are referred to as sentinel lesions in the early stages of primary malignant lymphoma of the central nervous system (PCNSL). In this study, we examined cases of PCNSL that presented with a sentinel lesion. Of the 43 PCNSL cases biopsied at our institution between 2011 and 2022, three cases were difficult to diagnose on initial biopsy. No preoperative steroids were used in all patients, and postoperative CT or MRI confirmed that the lesions were appropriately sampled from the targeted lesions. Since the diagnosis was not confirmed by the initial biopsy and symptoms were stable, the patients were followed up without chemotherapy, but symptoms worsened around 6 months later, and MRI showed recurrent large lesions. Another biopsy was performed in all patients, and a definitive diagnosis of diffuse large B-cell lymphoma (DLBCL) was finally obtained. It has been reported that sentinel lesions in PCNSL are characterized by demyelination or nonspecific inflammation on initial pathology and spontaneous resolution of lesions, which are estimated to be changes mediated by immunological mechanisms. In the present study, the course of symptoms was characterized by a relatively slow progression, and diffusion-weighted images at the initial onset did not show as high a signal as in usual PCNSL. Multiple biopsies are required to make a definitive diagnosis, and careful follow-up of symptoms and images and determination of the appropriate timing of biopsy are important.

Primary central nervous system lymphoma and the significance of sentinel lesions

Primary central nervous system lymphoma and the significance of sentinel lesions

Neuroimaging and clinicopathological differences between tumefactive demyelinating lesions and sentinel lesions of primary central nervous system lymphoma.

It is still a challenge to distinguish sentinel lesions of primary central nervous system lymphoma (PCNSL) from atypical tumefactive demyelinating lesions (TDLs) in clinical practice. We aimed to investigate potential differences of clinical features, neuroimaging findings and pathological characteristics between PCNSL and TDLs, improving early accurate diagnosis. It was a retrospective study involving 116 patients with TDLs and 150 patients with PCNSLs. All cases were pathologically confirmed. Clinical features, neuroimaging findings and pathological characteristics between two groups were analyzed. The onset age was 37 ± 14 years in TDLs and 58 ± 13 years in PCNSL(p=0.000). Main onset symptom was headache in TDLs, while cognitive impairment was frequently noted in PCNSL. CT brain scan image showed hypodense lesions in most cases of TDL (110/116, 94.8%), while approximately 80% patients (120/150) with PCNSL had hyperdense lesions. Furthermore, we found that the presence of Creutzfeldt-Peters cells (might be misdiagnosed as tumor cells) may serve as an important feature in TDLs. Onset age of patients with TDLs was younger than PCNSL. Neuroimaging features on brain CT scan might provide clues to make a differential diagnosis. Pathological features of PCNSL with sentinel lesions or following steroids therapy might mimic TDLs. Dynamic neuroimaging pathological and follow-up information were essential for an accurate diagnosis.

Neuroinflammation preceding primary central nervous system lymphoma (PCNSL) – Case reports and literature review

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extra-nodal non-Hodgkin’s lymphoma. Corticosteroids cause transient regression of PCNSL at the radiological and histological level. A growing number of case reports describe histologically confirmed neuroinflammation (sentinel lesions) heralding the development of PCNSL. We present two further cases of sentinel lesions contextualised by a review of past literature. Our aims are to collate existing knowledge on sentinel lesions in PCNSL and explore their pathophysiological significance. Two cases were identified (n = 2) from a cohort of 104 patients with PCNSL referred to a tertiary neurosurgery centre. A literature search identified previously reported cases (n = 14). Median age was 57.5 (range; 26–72); pre-biopsy corticosteroid administration was reported in 50% of cases (n = 8); mean time between biopsies was 10 months (range; 3–60). Common MRI features were homogenous enhancement (10;71.4%) and T2-hyperintensity (11;100%). Histochemical analysis of sentinel lesion biopsy revealed inflammatory CD3/4/5/8-positive T-cells (14; 100%), demyelination (13; 81.3%), rare/scattered CD20-postive B-cells (11;78.6%) and CD68-positive macrophages (10;71.4%). Repeat biopsy confirmed PCNSL in all cases. Waxing and waning CNS inflammation has been identified in 16 patients ultimately diagnosed with PCNSL. Neuro-specialists should be aware of this atypical presentation and maintain a high index of suspicion for lymphoma despite histopathology negative for lymphoma when clinical or radiological features indicate PCNSL.

High incidence of RAS pathway mutations among sentinel genetic lesions of Korean pediatric BCR-ABL1-like acute lymphoblastic leukemia.

IntroductionRecent advances in genetic analysis have led to the discovery of novel genetic subtypes of precursor B‐cell acute lymphoblastic leukemia (B‐ALL) with prognostic relevance. In this study, we studied a cohort of pediatric B‐ALL patients to retrospectively determine the incidence of patients harboring novel genetic subtypes, as well as their outcome.MethodsB‐ALL patients (N = 190) diagnosed in a single Korean hospital were included in the study. Patients' medical records were reviewed for data on established genetic abnormalities and outcome. CRLF2 expression was analyzed by quantitative RT‐PCR. Anchored multiplex PCR‐based enrichment was used to detect fusions and point mutations in 81 ALL‐related genes.ResultsIncidence of established recurrent genetic subtypes was as follows: high hyperdiploidy (21.6%), ETV6‐RUNX1 (21.6%), BCR‐ABL1 (7.9%), KMT2A rearrangement (7.4%) TCF3‐PBX1/TCF3‐HLF (7.4%), and hypodiploidy (1.1%). Incidence of new genetic subtypes was as follows: BCR‐ABL1‐like (13.2%), ETV6‐RUNX1‐like (2.1%), EWSR1‐ZNF384 (1.1%), and iAMP21 (1.1%). Median age at diagnosis of BCR‐ABL1‐like ALL was 6.8 years. According to type of genetic abnormality, BCR‐ABL1‐like ALL was divided into ABL class (12%), CRLF2 class (8%), JAK‐STAT class (12%), and RAS class (68%). The 5‐year event‐free survival (EFS) of BCR‐ABL1‐like patients was significantly inferior to non‐BCR‐ABL1‐like low‐ and standard‐risk patients (71.5 ± 9.1% vs 92.5 ± 3.2%, P = .001) and comparable to non‐BCR‐ABL1‐like high (75.2 ± 6.2%) and very high‐risk patients (56.8 ± 7.4%). All four ETV6‐RUNX1‐like patients survived event‐free.ConclusionAnalogous to previous studies, incidence of BCR‐ABL1‐like ALL in our cohort was 13.2% with outcome comparable to high and very high‐risk patients. A significantly high number of RAS class mutations was a distinct feature of our BCR‐ABL1‐like ALL group.

Features of cotton wool spots in diabetic retinopathy: a spectral-domain optical coherence tomography angiography study.

To describe the features of cotton wool spots (CWSs) in diabetic retinopathy (DR) by using spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCT angiography). We retrospectively studied patients with DR who presented CWSs and had been imaged by SD-OCT angiography. The retinal layer localisation and dimensions of the CWSs were assessed on SD-OCT, while the decorrelation signal generated by the CWSs and the vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus around the CWSs and in the macula were assessed on OCT angiography. A total of 87 eyes of 57 DR patients were included. All CWSs were located in the retinal nerve fibre layer and exhibited a decorrelation signal on OCT angiography. In 68 eyes (78.1%), hyporeflective cavities appearing as cysts in the CWS were noted, especially when were peripheral and large (P < 0.0001). The thickness averaged 211.8 ± 80.02mm and was positively influenced by recent diabetes history, glycaemic dysregulation, posterior pole localisation and a high VD of the SCP around the CWS, while the surface area averaged 0.33 ± 0.24mm2 and was influenced only by a low VD of the SCP around the CWS (P < 0.001). In 72 eyes (82.7%), the non-perfused areas were predominant in the periphery of the CWS. The features of CWSs are influenced by systemic factors, such as history and severity of diabetes, in association with local factors, such as localisation and retinal ischaemia. The peripheral localisation of ischaemia confirms the hypothesis that CWSs are sentinel lesions.

Tumefactive Demyelination versus Primary Central Nervous System Lymphoma on 18F-Fluorodeoxyglucose Positron Emission Tomography Magnetic Resonance Imaging: A Twist in the Tale.

Demyelinating lesions of the central nervous system (CNS) are classically known to be hypometabolic on 18F-Flurodeoxyglucose Positron Emission Tomography (18F-FDG PET). However, demyelinating lesions may show increased tracer uptake on 18F-FDG PET and can radiologically mimic neoplasm. Delayed tracer uptake on FDG PET is one of the diagnostic hallmarks of primary CNS lymphoma (PCNSL). Here, we present two cases in which the brain lesions showed increased FDG uptake on delayed integrated PET Magnetic Resonance Imaging (MRI), which were pathologically proven as CNS demyelination. Such demyelinating lesions may also act as “sentinel lesions” and potential harbinger of PCNSL on follow-up.

CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids)

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) has been recently identified as an inflammatory central nervous system (CNS) disorder. Punctate and curvilinear gadolinium enhancement (peppering) the pons is a characteristic magnetic resonance imaging (MRI) feature of CLIPPERS. Pathogenesis of this disorder remains unknown. A specific serum or cerebrospinal fluid biomarker for this disorder is currently unknown. Whether CLIPPERS is an actual new disease or just represents overlapping symptoms from multiple diseases is still debated. Many differential diagnoses exist even when using imaging as a tool. Pre-lymphoma states, such as grade I LYG (lymphomatoid granulomatosis) and sentinel lesions of primary CNS lymphoma are the most difficult to distinguish.

Abstract IA28: New targeted approaches for high-risk pediatric malignancies

Abstract While significant progress has been made in treating many pediatric malignancies, cancer remains the leading cause of death from disease in children. A number of childhood cancer subtypes remain particularly recalcitrant to dose-intensified cytotoxic treatment suggesting that new approaches are needed. Initial optimism that massively parallel sequencing efforts would reveal imminently targetable lesions has been tempered by a major finding that pediatric cancers often have simple genomes. While a signature mutation is frequently present, the product is often considered a difficult drug target, such as an aberrant transcription factor. Thus, the hope that cancer can be treated with combinations of drugs targeting specific gene mutations is unlikely to be imminently viable for most pediatric cancers. We hypothesized that while there is a notable paucity of events in easily druggable enzymes, a small number of sentinel lesions in an otherwise quiet genome may enable the discovery of synthetic lethal relationships with these key genetic events. Thus, we are applying unbiased approaches to identify key dependencies in pediatric cancers using functional genomic screening (shRNA and CRISPR) and chemical genomic screening. The primary goal is to connect key genetic lesions or disease lineages to new gene targets or small-molecule perturbations in the highest risk subtypes of pediatric cancers. Illustrative examples of our early findings will be presented. Citation Format: Kimberly Stegmaier. New targeted approaches for high-risk pediatric malignancies. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr IA28.

Sentinel lesions in osteoarticular traumatology: Signs to watch out for

Sentinel lesions are lesions of the bone or soft tissue, visible in standard X-rays carried out within a traumatic context, indicating bone or more severe capsular ligament lesions not visible on these X-rays. A detailed review of the peripheral joints as well as the spine is carried out with an example of each type of lesion in a standard X-ray. Confrontation with the reference examination, CT or MRI, depending on the case, is then carried out.

Inflammatory Demyelinating Brain Lesions Heralding Primary CNS Lymphoma

Brain biopsy plays a crucial role in the exploration of suspect white matter lesions in the differential diagnosis of primary central nervous system lymphoma (PCNSL) and inflammatory demyelination. We present the case of a previously healthy, immunocompetent woman, aged fifty-nine, who developed a histologically confirmed demyelinating white matter lesion months prior to the manifestation of a PCNSL. Similar cases of "sentinel lesions" preceding a PCNSL have been reported. In a literature review, we compared the diagnostic features that may be useful to differentiate a PCNSL from inflammatory demyelinating disease in older age. We conclude that the occurrence of large, contrast-enhancing cerebral lesions in older patients with a relapsing-remitting disease course and steroid-resistant vision disorders should lead to the consideration of a PCNSL.

Colorectal Neoplasm in Asymptomatic Average-risk Koreans: The KASID Prospective Multicenter Colonoscopy Survey

The incidence of colorectal cancer is increasing in Korea, but the epidemiology of colorectal neoplasm is not clearly defined. We aimed to elucidate the prevalence of colorectal neoplasm in average-risk Koreans and explore the underlying risk factors. A large-scale, multicenter, prospective study was conducted. Of the 19,460 subjects who underwent colonoscopy at 11 university hospitals, we analyzed 3,951 consecutive asymptomatic adults with no risk factors for colorectal cancer. The subjects were aged 52.1+/-11.6 years (mean+/-SD) and 60.1% of them were men. The prevalences of colorectal neoplasm and advanced neoplasm were 33.3% and 2.2%, respectively. The prevalence of a neoplasm increased with age (trend: p<0.001) and was higher in males (p<0.001). The prevalence of a proximal neoplasm was higher in subjects with a distal neoplasm than in those without a distal neoplasm (11.9% vs. 5.4%, p<0.001). However, 150 (52.1%) of the 288 subjects with a proximal neoplasm had no distal neoplasm. The overall prevalence of colorectal neoplasm in asymptomatic average-risk Koreans is comparable with that in Western countries. Being male and older are associated with a higher risk of colorectal neoplasm. Over half of proximal neoplasms are not associated with any distal sentinel lesions.

The Anatomical Distribution of Colorectal Cancer in Korea: Evaluation of the Incidence of Proximal and Distal Lesions and Synchronous Adenomas

The incidence of colorectal cancer throughout the Republic of Korea has been rising over the last 25 years. The change in incidence is supposed to be due to the westernized life style. We evaluated the anatomical distribution of colorectal cancer and the properties of synchronous adenomatous polyps in the Korean population which were known to be different from those in Western countries. From January 1997 to December 2006, 896 cases of colorectal cancer were reviewed retrospectively. A total of 25.1% were proximally located cancer with a modest female predominance (odds ratio 1.5). Synchronous adenomatous lesions were accompanied in 31.9% of all colorectal cancer cases. In the distal colorectal cancer patients, 18.8% had proximally located synchronous adenomas. In those with proximal colon cancer, only 20.5% of patients had distally located adenomas. The likelihood of a proximal colon cancer without distal sentinel lesions was higher in females (odds ratio 3.0). There has been a steep rise in the incidence of colorectal cancer in Korea and distal colon cancer is more prevalent than in Western countries. However, as over 20% of proximal colon cancers can exist without distal colonic synchronous or sentinel lesions, a total colonoscopic examination should be considered first in surveillance.

Tuberculids as sentinel lesions of tuberculous epididymo‐orchitis

Tuberculids are rarely associated with male genital tract tuberculosis (TB). Tuberculous epididymo-orchitis (TBEO) has been associated rarely with papulonecrotic tuberculid (PNT) but not with erythema induratum (EI) or the simultaneous occurrence of different tuberculids. A retrospective assessment of tuberculids that occurred with underlying TBEO was carried out. Five patients, four with one and one with two skin biopsies, with clinical diagnoses of PNT (two), EI (one), impetigo (two) and calf ulcer (one), formed the study cohort. Histopathological evaluation confirmed PNT and EI in four and two skin biopsies, respectively. Two patients who returned for follow-up were commenced on anti-tuberculous therapy. All patients sought medical attention 3-34 months later for tender right-sided (two) and left-sided (three) testicular masses. Orchidectomy was undertaken following a poor clinical response to empirical treatment with trimethoprim sulfamethoxazole. Pathological examination of the testis and epididymis confirmed TBEO. The patients were initiated on anti-tuberculous therapy. There was dramatic healing of the skin lesions. Tuberculids are a sentinel cutaneous manifestation of visceral TB and a valuable external audit of treatment compliance and response. Heightened recognition of and more rigorous genitourinary tract investigation are necessary to identify occult or asymptomatic TBEO as the underlying cause of tuberculids.

Colon Cancer Screening in 2005: Status and Challenges

The field of colon cancer screening has evolved dramatically in the last 15 years regarding evidence, guidelines, and practice. In 1990, no evidence from a randomized controlled clinical trial (RCT) existed to show that colorectal cancer (CRC) screening was effective in reducing CRC mortality. In 1990, although some guidelines endorsed screening, there was disagreement among recommending organizations about which tests to recommend or whether to recommend any screening tests at all. The US Preventive Services Task Force (USPSTF), arguably the most influential of the recommending organizations and the most rigorously evidence based, said that evidence was insufficient to recommend either for or against CRC screening.1 In this environment, CRC screening was not widely practiced, much less reimbursed by payers. If screening was performed at all, fecal occult blood testing (FOBT) was the most common test. Sigmoidoscopy was performed less frequently, and colonoscopy, rarely performed for screening, was used mainly for workup of a positive FOBT or sigmoidoscopy and for postpolypectomy surveillance. The primary questions facing academics, recommending organizations, and practicing clinicians in 1990 were (1) does CRC screening—of any kind—work to reduce CRC mortality, and (2) should it be implemented and reimbursed? In 2005, the situation is dramatically different. We now know that CRC screening works, and it is now being implemented and reimbursed. Colonoscopy has become popular as a primary screening test, and new tests, such as virtual colonoscopy, are being developed. The purpose of this article is to identify current challenges in light of the evolution of evidence, guidelines, and practice and to anticipate the next phase of development and implementation.

Prevalence of advanced colonic polyps in asymptomatic Chinese

To investigate the prevalence of advanced polyps in asymptomatic Chinese and to determine the risk of proximal advanced colonic polyps in subjects with and without polyps in the distal colon. Data were collected prospectively during colonoscopic examinations performed in 5 973 subjects as part of health evaluation at our unit from December 1997 to December 2003. Polyps were considered advanced, if they were larger than 10 mm or were tubovillous, villous or malignant. Proximal colon was defined as the splenic flexure and more proximal portions of the colon. Colon polyps were detected in 971 (16.3%) subjects (613 males and 358 females) with their mean age being 56.6+/-10.7 years. Advanced polyps were noted in 199 (3.3%) individuals. Subjects were sub-classified according to the location of polyps into three groups: distal (569, 58.6%), proximal (284, 29.2%), and combined proximal and distal (118, 12.2%) groups. Subjects with advanced polyps in these three groups were 95 (9.8%), 56 (5.8%), and 48 (4.9%) respectively. In the 48 subjects with advanced combined polyps, 13 advanced polyps were distributed at the distal colon, 17 at the proximal colon, and 18 at both. Eighteen colon cancers including 12 at sigmoid and 6 at ascending colon were confirmed by final pathology. The relative risk for advanced proximal polyp according to distal findings was 3.1 (95%CI: 1.3-7.4) for hyperplastic polyp, 2.7 (95%CI: 1.4-5.3) for tubular polyp and 13.5 (95%CI: 5.1-35.4) for advanced polyp as compared to that for no polyp. However, 56 (28.2%) of 199 subjects with advanced polyps had no index polyps at the distal colon and might go undetected under sigmoidoscopic screening. Although distal lesions can predict the risk of advanced proximal polyps, a substantial portion of Chinese with advanced proximal polyps is not associated with any distal sentinel lesions. These data have implications for screening policy of colon cancers in Taiwanese Chinese.

Distribución de la enfermedad polipoidea en la comarca interior de Vizcaya: implicación en pruebas diagnósticas y cribado del cáncer colorrectal

The importance of colonic polyp is increasing because colorectal cancer (CRC) screening is based on their identification. However, consensus is lacking on which technique should be used in CRC screening, whether colonoscopy or other methods such as sigmoidoscopy, which shows good sensitivity only in distal segments of the colon. We studied the characteristics and localization of polyps in our environment to verify their tendency to change localization and determine the implications of this in screening. We reviewed the prevalence and characteristics of colonic polyps in 3604 patients who underwent colonoscopy for various causes in our service, as well as their distribution in 837 patients with a diagnosis of polyps who underwent complete colonoscopy. Localization proximal or distal to the splenic flexure and polyp size (less than or more than 1 cm) were analyzed. Polyps were found in 28.3% of 3604 patients (11.7% showed polyps > or = 1 cm). Of the 837 patients who underwent complete colonoscopy, proximal polyps were found in 44.9% (14.6% showed polyps > or = 1 cm), while distal polyps were found in 79.9% (30.3% showed polyps > or = 1 cm). Both proximal and distal polyps were found in 24.8%. The probability of finding both proximal and distal lesions was 31%. Proximal lesions without distal lesions were found in 20% of the patients (5.6% presented polyps > or = 1 cm), and consequently sigmoidoscopy would miss 15.6% of polyps > or = 1 cm. A relatively high percentage of patients with proximal polyps > or = 1 cm would remain undiagnosed if complete colonoscopy were only performed in patients with distal polyps. Because of the well-known increase in the frequency of proximal polyps and because a considerable number of these present without distal sentinel lesions, there are increasing arguments for considering colonoscopy as the basic technique for CRC screening.

Diaphragmatic endometriosis: diagnosis, surgical management, and long-term results of treatment

Objective: To describe symptoms, surgical diagnosis and treatment, and long-term outcome of patients with symptomatic diaphragmatic endometriosis. Design: Observational follow-up study. Setting: American tertiary referral center for the surgical treatment of endometriosis. Patient(s): Eight patients with diaphragmatic endometriosis causing severe or disabling symptoms. Intervention(s): Laparoscopic diagnosis of diaphragmatic endometriosis followed by upper abdominal laparotomy for full-thickness resection of the diaphragm. Main Outcome Measure(s): Reduction of several symptoms as measured on a 5-point ranked ordinal scale administered by a phone survey up to 7 years after surgery. Result(s): Laparoscopy from an umbilical port may identify small “sentinel lesions” of endometriosis on the anterior or mid diaphragm. Eight symptomatic patients all had significant invasive disease with dimensions up to 5 cm across of the posterior right diaphragm, which could not always be seen from the umbilical port site. All such lesions can be seen by a laparoscope placed beneath the right costal margin. Laparoscopic treatment of symptomatic disease is not rational given the posterior placement of the disease out of sight behind the liver and the full-thickness nature of the disease in all eight patients. Laparotomy with full thickness resection of the diaphragm resulted in complete eradication of symptoms in seven of eight patients, and good symptomatic reduction in one. Conclusion(s): Treatment of diaphragmatic endometriosis by laparotomy results in a high rate of symptom relief. Laparoscopic treatment of diaphragmatic endometriosis will result in a high rate of incomplete diagnosis and incomplete treatment with a high rate of continuing symptoms.

The Topography of Colorectal Cancer Varies by Race/Ethnicity and Affects the Utility of Flexible Sigmoidoscopy

Colorectal cancer screening beginning at age 50 is recommended for all Americans considered at "average" risk for the development of colorectal cancer either with flexible sigmoidoscopy and fecal occult blood testing (FOBT) or with colonoscopy. Patients who elect flexible sigmoidoscopy and FOBT undergo full colonoscopy only if left-sided neoplasia is detected or if the FOBT is positive. Unfortunately in blacks and whites most right-sided colorectal lesions are unaccompanied by left-sided sentinel lesions, which leads some to prefer colonoscopic screening in these patients. The topography of colorectal cancer in Asians and Latinos is unavailable. We used 1988-1995 California Cancer Registry data to determine the topography of 105,906 consecutive colorectal cancers among Asian, black, Latino, and white patients. We found that the proportion of colorectal cancer distal to the splenic flexure and therefore detectable by flexible sigmoidoscopy varied by ethnicity: Asian (71%) > Latino (63%) > white (57%) > black (55%); P < 0.001. These differences were significant after adjusting for age and sex. The risk of distal disease relative to whites was 1.61 in Asians, 1.15 in Latinos, and 0.82 in blacks (P < 0.001). Flexible sigmoidoscopy detects a higher proportion of colorectal cancers in Asians and Latinos than in whites or blacks. Further study is needed to assess whether the topography of benign colorectal neoplasia parallels that of malignant disease. Colorectal screening recommendations may need to incorporate racial and ethnic differences in colorectal neoplasia topography.

Primary central nervous system lymphoma: from clinical presentation to diagnosis.

Immunocompetent patients with primary central nervous system lymphoma (PCNSL) present with a median age of 55 years, immunosuppressed patients with a median age of 40 years. They show a broad range of signs and symptoms. Symptoms of increased intracranial pressure and personality change are most frequent, followed in frequency by ataxia and hemiparesis. The median time from onset of symptoms to diagnosis is 3-5 months in immunocompetent patients and 2 months in immunodeficient patients. The time to diagnosis can be considerably longer in patients with slowly developing personality change or fluctuating symptoms due to spontaneous or steroid-induced remission of so-called sentinel lesions. Native CT scans show iso- or hyperdense lesions with homogenous contrast enhancement. T1-weighted MRI scans show hypointense and T2-weighted scans hyperintense lesions. The definitive diagnosis of PCNSL requires biopsy. In some cases, however, the definitive diagnosis may exclusively be made by the demonstration of malignant B-lymphocytes in the cerebrospinal fluid.