Treatment of extranodal lymphomas

Diffuse Large B-Cell Non-Hodgkin Lymphoma Involving Multiple Different Organs in a Young Adult with 18F-FDG PET/CT

Extranodal-multiorgan involvement is rarely presented in diffuse large B-cell non-Hodgkin lymphoma. ¹⁸Fluorine-fluorodeoxyglucose positron emission tomography/computed tomography findings of a 22-year-old female patient with supra/infra-diaphragmatic nodal and skeletal involvements and thyroid, pancreas, right breast, bilateral renal, and ovarian involvements were presented.

Association of antiviral prophylaxis and rituximab use with posttransplant lymphoproliferative disorders (PTLDs): A nationwide cohort study

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation (SOT). Most PTLD cases are associated with Epstein-Barr virus (EBV) infection. The role of antiviral prophylaxis or rituximab therapy for prevention of PTLD in SOT recipients is controversial. In a nationwide cohort, we assessed the incidence, presentation, and outcome of histologically proven PTLD. We included 4765 patients with a follow-up duration of 23 807 person-years (py). Fifty-seven PTLD cases were identified; 39 (68%) were EBV positive (EBV+ PTLD). Incidence rates for EBV+ PTLD at 1, 2, and 3 years posttransplant were 3.51, 2.24, and 1.75/1000 py and 0.44, 0.25, and 0.29/1000 py for EBV- PTLD. We did not find an effect of antiviral prophylaxis on early and late EBV+ PTLD occurrence (early EBV+ PTLD: SHR 0.535 [95% CI 0.199-1.436], p = .264; late EBV+ PTLD: SHR 2.213, [95% CI 0.751-6.521], p = .150). However, none of the patients (0/191) who received a rituximab-containing induction treatment experienced PTLD, but 57 of 4574 patients without rituximab induction developed PTLD. In an adjusted restricted mean survival time model, PTLD-free survival was significantly longer (0.104 years [95% CI 0.077-0.131]) in patients receiving rituximab as induction treatment. This study provides novel data on the association of rituximab induction and reduced risk for PTLD.

Extranodal Lymphomas: a pictorial review for CT and MRI classification

Extranodal lymphomas represent an extranodal location of both non-Hodgkin and Hodgkin lymphomas. This study aims to evaluate the role of CT and MRI in the assessment of relationships of extranodal lymphomas with surrounding tissues and in the characterization of the lesion. We selected and reviewed ten recent studies among the most recent ones present in literature exclusively about CT and MRI imaging of extranodal lymphomas. Contrast-enhanced computed tomography (CT) is usually the first-line imaging modality in the evaluation of extranodal lymphomas, according to Lugano classification. However, MRI has a crucial role thanks to the superior soft-tissue contrast resolution, particularly in the anatomical region as head and neck. (www.actabiomedica.it)

Computed tomography patterns of pulmonary and pleural involvement in lymphoma

Background

Pulmonary and pleural involvement is fairly common in patients with lymphoma, especially in the setting of progressive or recurrent disease. Pleuropulmonary involvement in lymphoma may occur as a single pattern or as a combination of multiple patterns which can often mimic unrelated pathologies.

Methods

Review of our institutional database from 01 Jan 2015 to 04 Oct 2017 revealed 90 patients with pulmonary and/or pleural lesions attributable to lymphoma. These lesions were classified into various categories, and the pattern of involvement was evaluated.

Results

Pulmonary involvement was seen in 17.6% of patients with Hodgkin lymphoma (HL) and in 10.5% of patients with non-Hodgkin lymphoma (NHL), whereas pleural involvement was seen in 6.5% of patients with NHL. Almost all the patients in our study had findings belonging to multiple categories. Pulmonary involvement in patients with HL was seen in the form of nodules (51.6%), masses (51.6%), and direct extension from a mediastinal/hilar mass (45.2%). Patients with NHL had pulmonary involvement in the form of nodules (42.4%), direct extension from a mediastinal/hilar mass (25.4%), pulmonary masses (18.6%), and interstitial pattern (2.4%). Pleural thickening (61.5%), masses (30.8%), and effusion (15.4%) were the three patterns of pleural involvement.

Conclusion

Nodules and masses were the two commonest patterns of pulmonary involvement in patients with HL, whereas nodules were the commonest pattern noted in patients with NHL. Pulmonary masses were seen more commonly in patients with HL than in those with NHL. Pleural involvement was seen exclusively in patients with NHL.

Simultaneous occurrence of invasive pulmonary aspergillosis and diffuse large B-cell lymphoma: case report and literature review

Background

Patients with lymphoma are at risk for developing pulmonary opportunistic infections due to immunocompromise. However, clinical reports of concurrent lymphoma and opportunistic infection at presentation are rare and often confined to single cases. A delayed diagnosis of either opportunistic infection or lymphoma usually occurs in this complex situation. Here, we report such a case and analyse 18 similar cases searched in the PubMed database to deepen clinicians’ understanding.

Case presentation

A 48-year-old man presented with a 3-month history of fever, cough and emaciation. High-resolution computed tomography revealed bilateral cavitating lesions of different sizes. Aspergillus fumigatus complex was identified from a bronchoalveolar lavage fluid culture. However, antifungal treatment combined with multiple rounds of antibacterial therapy was unsuccessful, and the patient’s lung lesions continued to deteriorate. Multiple puncture biopsies finally confirmed the coexistence of diffuse large B-cell lymphoma. Despite the initiation of combination chemotherapy, the patient died of progressive respiratory failure.

Conclusions

Synchronous pulmonary lymphoma and simultaneous opportunistic infection is rare and usually lacks specific clinical and imaging manifestations. Lymphoma should be considered as part of the differential diagnosis of patients with an opportunistic infection when treatment fails or other symptoms are present that could be considered “atypical” for the condition. Tissue biopsy is the gold standard, and multiple biopsies are essential for making the final diagnosis and should be performed upon early suspicion.

Prognostic value of SUVmax measured by pretreatment 18F-FDG PET/CT in patients with primary gastric lymphoma

PURPOSE

The aim of this retrospective study was to determine whether glucose metabolism assessed by fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) provides prognostic information independent of established prognostic factors in patients with gastric lymphoma.

PATIENTS AND METHODS

We reviewed the medical records of 86 patients retrospectively (men, 42; women, 44; mean age 58±13 years) with pathologically proven gastric lymphoma (34 mucosa-associated lymphoid tissue and 52 aggressive non-Hodgkin's lymphoma). They underwent F-FDG PET/CT as part of a pretreatment work-up from February 2004 to July 2012. For the analysis, patients were classified by age, sex, Musshoff stage, serum lactate dehydrogenase, International Prognostic Index score, extragastric spread, and visual intensity [visual assessment and maximum standardized uptake value (SUVmax), respectively]. The relationship between F-FDG uptake and survival was analyzed using the Kaplan-Meier method with a log-rank test and Cox's proportional-hazard regression method.

RESULTS

The median survival of all 86 study participants was 1117 days and the median SUV measured by PET/CT was 6.1 (range, 1.9-32.7). Patients with an SUVmax less than or equal to 5.2 survived significantly longer than patients with an SUVmax more than 5.2 (median, 1163 vs. 1004 days; P=0.003). Survival was also found to be significantly related to age (P=0.0005), histological type (P=0.004), extragastric spread (P=0.0004), International Prognostic Index score (P<0.0001), serum lactate dehydrogenase (P=0.02), stage (P<0.0001), and visual intensity (P=0.041). A multivariate analysis showed that patients with a higher SUVmax [P=0.021; 95% confidence interval (CI), 1.52-8.14; hazard ratio (HR)=6.29], older age (P=0.001; 95% CI, 4.64-219.96; HR=18.8), more aggressive histologic type (P=0.006; 95% CI, 2.20-70.63; HR=12.76), and higher stage (P=0.0006; 95% CI, 5.81-206.43; HR=17.48) showed worse survival.

CONCLUSION

A higher SUVmax on pretreatment F-FDG PET/CT can predict poorer survival in patients with gastric lymphoma.

18F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

AIM

To compare ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.

METHODS

Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ¹⁸F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ² test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma.

RESULTS

Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.

CONCLUSION

PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

Fluorine-18 fluorodeoxyglucose PET-CT for extranodal staging of non-Hodgkin and Hodgkin lymphoma

PURPOSE

We aimed to evaluate the role of fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) involving care-dose unenhanced CT to detect extranodal involvement in patients with non-Hodgkin and Hodgkin lymphoma.

MATERIALS AND METHODS

Lymphoma patients (35 Hodgkin lymphoma, 75 non-Hodgkin lymphoma) who were referred for 18F-FDG PET-CT imaging, following a diagnostic contrast-enhanced CT (CE-CT) performed within the last month, were included in our study. A total of 129 PET-CT images, and all radiologic, clinical, and pathological records of these patients were retrospectively reviewed.

RESULTS

In total, 137 hypermetabolic extranodal infiltration sites were detected by 18F-FDG PET-CT in 62 of 110 patients. There were no positive findings by CE-CT that reflected organ involvement in 40 of 137 18F-FDG-positive sites. The κ statistics revealed fair agreement between PET-CT and CE-CT for the detection of extranodal involvement (κ=0.60). The organs showing a disagreement between the two modalities were the spleen, bone marrow, bone, and thyroid and prostate glands. In all lesions that were negative at CE-CT, there was a diffuse 18F-FDG uptake pattern in the PET-CT images. The frequency of extranodal involvement was 51% and 58% in Hodgkin and non-Hodgkin lymphoma patients, respectively. There was a high positive correlation between the maximum standardized uptake values of the highest 18F-FDG-accumulating lymph nodes and extranodal sites (r=0.67) in patients with nodal and extranodal involvement.

CONCLUSION

18F-FDG PET-CT is a more effective technique than CE-CT for the evaluation of extranodal involvement in Hodgkin and non-Hodgkin lymphoma patients. PET-CT has a significant advantage for the diagnosis of diffusely infiltrating organs without mass lesions or contrast enhancement compared to CE-CT.

PET/Computed Tomography in the Diagnosis and Staging of Gastric Cancers

Although there has been a reduction of the incidence and mortality of gastric cancer, it remains among the commonest causes of cancer-related death. Accurate staging and evaluation of treatment response are vital for management. PET is used to complement anatomic imaging in cancer management. PET/computed tomography (CT) has demonstrated its potential value for preoperative staging, evaluation of response to therapy, and detection of recurrence. Not all types of gastric cancers have a high affinity for fluorodeoxyglucose. PET/CT in the evaluation and staging of gastric cancer is not established, but studies indicate that there may be an evolving role for this imaging modality.

Clinical value of 18F-FDG PET/CT in diagnosis and follow-up of primary gastric lymphoma

AIM: To assess the clinical value of ¹⁸F-fluorodeoxygiucose positron emission computed tomography (¹⁸F-FDG PET/CT) in the diagnosis and follow-up of primary gastric lymphoma (PGL).

METHODS: Thirty-five patients with endoscopically or pathologically confirmed PGL were enrolled into this study. Among them, 12 patients underwent pre-treatment ¹⁸F-FDG PET/CT scans, and the other 23 patients (32 episodes) underwent a total of 32 post-treatment ¹⁸F-FDG PET/CT scans, with 8 scanned 2-3 times. The lesions on the images of ¹⁸F-FDG PET/CT were observed and analyzed, and the SUVmax was measured.

RESULTS: Among the 12 patients who underwent pre-treatment ¹⁸F-FDG PET/CT scans, 5 had infiltration type PGLs and showed gastric wall thickening [SUVmax = 22.5 ± 7.6 (7.2-30.9), average thickness = 3.4 cm ± 1.3 cm (1.2-4.8 cm)], 6 had nodule type [SUVmax = 24.2 ± 13.0 (5.8-39.4), average diameter = 2.8 cm ± 1.5 cm (1.0-4.6 cm), and 1 had mass type (SUVmax = 21.0, size = 19.5 cm × 1.4 cm). Among the 23 patients who underwent after-treatment ¹⁸F-FDG PET/CT scans, using endoscopic pathology or clinical follow-up beyond six months as standard, 11 had negative images, and the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of ¹⁸F-FDG PET/CT were 83.3% (10/12), 1.7% (11/12), 87.5% (21/24), 84.6% (11/13) and 84.6% (11/13), respectively.

CONCLUSION: ¹⁸F-FDG PET/CT plays an important role in the pre-treatment diagnosis of PGL as well as post-treatment surveillance of PGL from a clinical perspective.

Rare case of Primary Pulmonary Extranodal Non-Hodgkin's Lymphoma in a Patient with Sjogren's Syndrome: Role of FDG-PET/CT in the Initial Staging and Evaluating Response to Treatment

A 64-year old woman with a long standing Sjogren's syndrome was undergoing evaluation for renal transplant surgery when two pulmonary opacities were detected on chest CT. Subsequent biopsy revealed extranodal marginal B-cell non-Hodgkin's lymphoma (NHL). An FDG-PET/CT scan was then performed which demonstrated isolated FDG avid pulmonary involvement. After therapy, FDG-PET/CT scans showed good response to treatment with near complete resolution of FDG avidity. This rare case illustrates the rare pulmonary manifestation of extranodal lymphoma in a patient with Sjogren's syndrome and emphasizes the value of FDG PET/CT in the initial staging and evaluation of response to treatment, which has not previously been published.

CONFLICT OF INTEREST

None declared.

Primary gastric lymphoma: utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography for detecting relapse after treatment

The purpose of this study was to evaluate the role of 18F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) in detecting relapse in patients with primary gastric lymphoma (PGL) post-treatment. Data of 39 previously treated patients with PGL (age: 50.3 ± 13.8 years; male: 24) who underwent 71 (18)F-FDG PET-CT studies for suspected relapse (n = 53) or routine follow-up (n = 18) were retrospectively evaluated. PET-CT images were evaluated both qualitatively and quantitatively (standardized uptake value [SUVmax]). A combination of clinical/imaging follow-up, endoscopy and/or histopathology was taken as the reference standard. The per patient based sensitivity of PET-CT was 96%, specificity 91% and accuracy 93%. The lymph node was the commonest site of relapse on PET-CT. Mean lesion SUVmax was 5.9 ± 3.1 (2.3-13.6). Accuracy was similar in suspected relapse and routine follow-up groups (90.5% vs. 100%; p = 0.409). Based on the data, (18)F-FDG PET-CT appears to be highly accurate for the detection of relapse in patients with PGL post-treatment.

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.

Cranio-maxillofacial non-Hodgkin's lymphoma: clinical and histological presentation

Non-Hodgkin's lymphoma represents about 5% of all malignant lesions of the head and neck. In this study we retrospectively evaluated clinical presentation, histological subtype and long-term prognosis of 42 patients with non-Hodgkin's lymphoma involving the craniofacial area. The mean age at diagnosis was 64 years. More than half of the patients presented with disseminated disease at multiple sites (55%, n=23). In 62% (n=26) the first manifestation was extranodal. The most common affected region was the oral cavity (65%, n=17). Treatment consisted of local therapy, including surgical resection and radiation, as well as chemotherapy with or without local therapy. Recurrence occurred in 31% (n=13) of the treated patients. Mean survival after first diagnosis varied from 17 months in patients presenting with diffuse large B-cell lymphoma (DLBCL), to 8.5 years in patients with follicular lymphoma. The most common histological subtype is DLBCL. Standard treatment for DLBCL consists of chemotherapy combined with CD 20 monoclonal antibody, even after total resection of the tumour. There is high risk of systemic disease in patients presenting with non-Hodgkin's lymphoma and high risk of post therapy recurrence.

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.

Surgery does not adversely affect survival in primary gastrointestinal lymphoma

OBJECTIVE

To evaluate the impact of surgery on gastrointestinal lymphoma.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried from 1973 to 2005.

RESULTS

A total of 17,222 cases of PGIL were identified. The overall incidence of PGIL was approximately 1.505 cases per 100,000. A significantly increasing incidence for PGIL was observed (APC = +4.67, P < 0.05). In the cases for which treatment data was available, resection occurred in roughly half of the patients. In univariate analysis, surgical extirpation did not improve survival (47 months vs. 76 months, P < 0.001), while radiation treatment improved median survival (77 months vs. 59 months, P < 0.001). Multivariate analysis revealed increasing age and male gender as independent predictors of decreased overall survival. Tumor location also was a significant predictor of outcome. Large B-cell lymphoma type PGIL had a poorer prognosis than marginal zone B-cell lymphoma. By multivariate analysis, surgery was not found to increase the risk of death (HR = 0.99).

CONCLUSIONS

No associated survival benefit for surgery in the treatment in gastrointestinal lymphoma was observed. Determination of lymphoma should preclude surgical resection. Nonetheless, inadvertent extirpative surgery or in association with perforation does not appear to increase mortality.

Clinicopathologic characteristics of T-cell non-Hodgkin's lymphoma: a single institution experience

BACKGROUND/AIMS

Although the incidence of T-cell non-Hodgkin's lymphoma (NHL) is higher in Far East Asia than in Western countries, its incidence and clinical course in Korea are not well-defined. Therefore, we assessed the relative frequency and clinical features of T-cell NHL in Korea.

METHODS

We performed a retrospetcive analysis of 586 patients with NHL.

RESULTS

101 (17.2%) had T-cell NHL. The most frequent subtypes of T-cell NHL were extranodal NK/T-cell lymphoma, nasal type (NASAL), peripheral T-cell lymphoma, unspecified type (PTCL-U), and anaplastic large cell lymphoma, T/null cell, primary systemic type (ALCL). The seven pathological subtypes could be classified into three prognostic subgroups. When patients with the three most frequent subtypes were grouped together, their survival was reflected in the International Prognostic Index (IPI) scores. Univariate analysis of IPI elements and other clinical features showed that clinical stage and extranodal sites were significant predictors of survival. Cox multivariate analysis showed that the number of extranodal sites was the only independent prognostic indicator.

CONCLUSIONS

The relative frequency of T-cell NHL seems to be decreasing in Korea, although NASAL remains frequent. Korean patients with ALCL appear to have an unfavorable prognosis. Large-scale studies are warranted for Korean patients with T-cell NHL.

FDG avidity and PET/CT patterns in primary gastric lymphoma

PURPOSE

The use of 18F-fluoro-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in primary gastric lymphoma (PGL) is challenging due to physiologic FDG activity in the stomach and variability in the degree of uptake in various histologic subtypes. This study assesses FDG avidity and PET/CT patterns in newly diagnosed PGL.

METHODS

Sixty-two PET/CT studies of newly diagnosed PGL were reviewed (24 low-grade mucosa-associated lymphoid tissue [MALT], 38 aggressive non-Hodgkin's lymphoma [AGNHL]). FDG avidity, patterns (focal/diffuse), and intensity (visually vs. the liver and SUVmax) were assessed and compared to 27 controls. Gastric CT abnormalities and extragastric sites were recorded.

RESULTS

Gastric FDG uptake was found in 55/62 (89%) PGL (71% MALT vs. 100% AGNHL, p < 0.001) and 63% controls. A diffuse pattern was found in 60% PGL (76% MALT vs. 53% AGNHL, p = NS) and 47% controls. FDG uptake higher than liver was found in 82% PGL (58% MALT vs. 97% AGNHL, p < 0.05) and 63% controls. SUVmax in FDG-avid PGLs was 15.3 +/- 11.7 (5.4 +/- 2.9 MALT vs. 19.7 +/- 11.5 AGNHL, p < 0.001) and 4.6 +/- 1.4 in controls. CT abnormalities were found in 79% PGL (thickening, n = 49; ulcerations, n = 22). Extra-gastric FDG-avid sites were seen in none of MALT, but 61% of AGNHL (nodal, n = 18; nodal and extranodal, n = 5).

CONCLUSIONS

FDG avidity was present in 89% of PGLs, including all patients with AGNHL but only 71% of MALT. FDG uptake can be differentiated, in particular in AGNHL-PGL, from physiologic tracer activity by intensity but not by pattern. Extragastric foci on PET and structural CT abnormalities are additional parameters that can improve PET/CT assessment of PGL. Defining FDG avidity and PET/CT patterns in AGNHL and a subgroup of MALT-PGL before treatment may be important for further monitoring therapy response.

Fluorine-18 Fluorodeoxyglucose PET/CT Patterns of Extranodal Involvement in Patients with Non-Hodgkin Lymphoma and Hodgkin's Disease

Lymphoma may originate in extranodal sites. Extranodal lymphoma may also be secondary to and accompany nodal disease. Fluorine-18 fluorodeoxyglucose (18F-FDG) imaging has an essential role in the staging of lymphoma, in monitoring the response to therapy, and in detection of recurrence. The introduction of 18F-FDG PET/CT hybrid imaging allows for accurate localization of disease and may be specifically beneficial for the detection of unexpected extranodal sites of disease or exclusion of disease in the presence of nonspecific extranodal CT findings. Accurate staging and localization often dictate the appropriate treatment strategy in patients with lymphoma. Therefore, at any stage in the course of the disease, the potential presence of extranodal disease should be considered when interpreting 18F-FDG PET/CT studies in patients with non-Hodgkin lymphoma and Hodgkin's disease.

Primary gastrointestinal tract lymphoma: diagnosis and management of common neoplasms

Primary gastrointestinal lymphoma represents the most common location of extranodal lymphoma. With the bulk of disease manifesting within the gastrointestinal tract and contiguous lymph nodes, many of the lymphomas occurring in the peripheral lymph nodes can also present with primary gastrointestinal tract involvement. Molecular biology has recently enabled significant progress in the diagnosis and management of primary gastrointestinal lymphoma. Herein, we will discuss the major lymphomas affecting the bowel and highlight their key morphological, immunophenotypical and molecular diagnostic attributes. Similarly, in keeping with recent therapeutic advances, we will briefly discuss some important treatment considerations. Thus, this review is intended to offer clinicians and pathologists an overview of primary gastrointestinal lymphomas.

Primary gastric lymphoma pathogenesis and treatment: what has changed over the past 10 years?

Primary gastric (PG) lymphomas are generally non-Hodgkin lymphomas (NHL). They represent 5% of gastric malignancies and show an apparently increasing incidence worldwide. The most common histological subtypes are diffuse large B-cell and marginal zone B-cell NHL of the mucosa-associated lymphoid tissue (MALT)-type. Pathogenesis is often related to Helicobacter pylori infection (HPI). There is still no consensus on the optimal treatment for PG lymphoma. Nowadays surgery is limited to rare cases and radiotherapy--combined or not with chemotherapy--represents an effective therapeutic option ensuring long-term, organ-salvage benefits mainly in aggressive histological subtypes. Additionally, the description of MALT lymphomas has made the situation even more complex, because antibiotics alone can induce lasting remissions in those cases associated with HPI. Consequently, a global therapeutic approach to the cure of PG-NHL has completely changed over the last 10 years: innovative, conservative options to reduce treatment toxicity, thus preventing systemic relapses, have made their appearance and are on the rise.

FDG-PET scanning for detection and staging of extranodal marginal zone lymphomas of the MALT type: a report of 42 cases

BACKGROUND

Although reports have suggested that FDG-PET scans were not useful for staging of extranodal marginal zone lymphomas (MZL), experience at our center suggests otherwise. Thus we reviewed the findings of FDG-PET scans in patients with extranodal MZL seen at our center.

PATIENTS AND METHODS

A database of 175 patients with histologically-confirmed diagnoses of extranodal MZL was reviewed. Forty-two patients who had had FDG-PET scans for initial staging were identified. All information was obtained by retrospective review of medical records and PET scans.

RESULTS

Thirty-four (81%) patients had focal tracer uptake within verified tumor sites, six (14%) patients did not, and two (5%) patients had indeterminate uptake. Seven of the 34 (21%) patients with uptake within verified tumor sites had uptake in regional lymph nodes and four patients were upstaged due to FDG-PET findings. Eight patients also obtained post-treatment FDG-PET scans. In five of those eight, the repeated FDG-PET scan indicated a complete response, and in three there was an indeterminate or mixed response.

CONCLUSION

FDG-PET scans carried out for initial staging of extranodal MZL detected disease in a high proportion of patients. This study suggests that imaging with FDG-PET scans is useful for both initial staging and follow-up of patients with extranodal MZL.