Bone marrow involvement in young patients with non-Hodgkin's lymphoma: the importance of multiple bone marrow samples for accurate staging

18F-FDG PET/CT versus bone marrow biopsy in detecting bone marrow infiltration in initial staging of pediatric lymphoma

BACKGROUND

To evaluate the efficacy of PET/CT using18F-FDG (18F-fluorodeoxyglucose) as a radiotracer compared to conventional bone marrow biopsy (BMB) in detecting infiltration to bone marrow (BM) in pediatric patients with lymphoma at the time of initial diagnosis.

METHODS

66 pediatric patients with lymphoma (47Hodgkin's and 19non-Hodgkin's lymphoma) were referred for initial staging by18F-FDG PET/CT study. All patients underwent bilateral iliac BMB and 18F-FDG PET/CT scan with no more than 2 weeks interval in-between. Follow-up for at least 6 months was used as a reference standard to compare diagnostic performance between two modalities in detecting bone marrow infiltration (BMI).

RESULTS

Sensitivity, specificity, accuracy, as well as positive and negative predictive values of 18F-FDG PET/CT in detecting BMI were (80%, 86%, 85%, 63%, and 94%) in contrast to BMB (80%, 53%, 59%, 33%, and 90%) respectively. 18F-FDG PET/CT was concordant to BMB in 39/66 patients (59%).

CONCLUSION

18F-FDG PET/CT was more accurate and specific, with higher predictive values than BMB in detecting BMI during initial staging of pediatric lymphoma. In most pediatric lymphoma patients, 18F-FDG PET/CT can be used instead of BMB to determine BMI during their initial staging process.

Whole-Body Magnetic Resonance Imaging: Current Role in Patients with Lymphoma

Imaging of lymphoma is based on the use of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) and/or contrast-enhanced CT, but concerns have been raised regarding radiation exposure related to imaging scans in patients with cancer, and its association with increased risk of secondary tumors in patients with lymphoma has been established. To date, lymphoproliferative disorders are among the most common indications to perform whole-body magnetic resonance imaging (MRI). Whole-body MRI is superior to contrast-enhanced CT for staging the disease, also being less dependent on histology if compared to ¹⁸F-FDG-PET/CT. As well, it does not require exposure to ionizing radiation and could be used for the surveillance of lymphoma. The current role of whole-body MRI in the diagnostic workup in lymphoma is examined in the present review along with the diagnostic performance in staging, response assessment and surveillance of different lymphoma subtypes.

Diagnostic performance of 18F-2-fluoro-2-deoxy-D-glucose PET/computerized tomography in identifying bone marrow infiltration in new patients with diffuse large B-cell lymphoma and Hodgkin lymphoma

OBJECTIVE

To compare between F-2-fluoro-2-deoxy-D-glucose PET/computerized tomography (F-FDG PET/CT) and routine iliac bone marrow biopsy (BMB) in assessment of bone marrow infiltration (BMI) in Hodgkin lymphoma and diffuse large B-cell lymphoma (DLBCL) patients at initial presentation.

PATIENTS AND METHODS

A retrospective analysis of 138 patients (50 Hodgkin lymphomas, 88 DLBCLs). The study included 70 males and 68 females with median age of 43 years. All patients underwent F-FDG PET/CT and iliac crest BMB before treatment. Any focal or patchy FDG uptake in the bone marrow, superior-to hepatic uptake was interpreted as abnormal with or without corresponding CT changes. Treatment response was evaluated clinically with each cycle of chemotherapy, radiologically after three cycles and at the end of treatment.

RESULTS

The overall diagnostic performance showed significant higher sensitivity of F-FDG PET/CT than that of BMB (73.9 versus 62.5%, P = 0.046), while the specificity was higher in BMB than in F-FDG PET/CT (100% in BMB versus 93.5% in F-FDG PET/CT). In Hodgkin lymphoma, sensitivity, negative predictive value (NPV) and accuracy were significantly higher in F-FDG PET/CT compared with BMB, being 87.5, 94.4 and 96% versus 50, 81 and 84% (P = 0.02, 0.03, 0.04, respectively). However, for DLBCL patients, almost comparable results were found between both tests in terms of sensitivity, NPV and accuracy (66.7, 83.9 and 81.8% versus 68.8, 84.9 and 88.6%, respectively). After PET/CT scan, 12 patients (8.6%) were upstaged to stage IV, eight of them were negative by BMB.

CONCLUSION

F-FDG PET/CT seemed to be an excellent diagnostic test in assessment of BMI at initial assessment and staging of Hodgkin lymphoma and DLBCL patients.

Diagnostic and Clinical Impact of Staging 18F-FDG PET/CT in Mantle-Cell Lymphoma: A Two-Center Experience

INTRODUCTION

The diagnostic accuracy of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in staging mantle-cell lymphoma has not yet investigated. The aim of this 2-center retrospective study was to investigate the utility of ¹⁸F-FDG PET/CT in assessing nodal, splenic, bone marrow (BM), and gastrointestinal (GI) disease compared to CT, BM, and GI endoscopy; and to assess its clinical impact.

PATIENTS AND METHODS

One hundred twenty-two patients with histologically proven mantle-cell lymphoma were included. PET/CT BM findings were considered positive if isolated/multiple focal uptake in the BM not explained by benign findings and/or diffuse BM uptake higher than liver with/without focal uptakes were present. PET/CT findings were considered positive for GI involvement in the presence of isolated/multiple focal uptake in the GI organ.

RESULTS

All patients had positive PET/CT showing the presence of at least one hypermetabolic lesion, with the exception of one case. PET/CT results, compared to CT, detected more nodal and/or splenic lesions in 26 patients. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT for BM were 52%, 98%, 97%, 65%, and 74%; for GI 64%, 91%, 69%, 90%, and 85%; and for GI excluding diabetic patients, 78%, 92%, 72%, 94%, and 89%. PET/CT permitted upstaging of 21 cases and downstaging of 2.

CONCLUSION

¹⁸F-FDG PET/CT showed excellent detection rate in nodal and splenic disease-a rate better than CT. For BM and GI evaluation, in order to reach good accuracy, the selection of patients and the use of specific criteria for evaluation of these organs seems to be crucial. Moreover, PET/CT altered the management and therapeutic approach in about 20% of patients.

Positron Emission Tomography-based Analysis Can Accurately Predict Bone Marrow Involvement With Mantle Cell Lymphoma

INTRODUCTION

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma and requires both bone marrow biopsy and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to correctly stage the disease at diagnosis. However, accurate identification of bone marrow involvement by lymphoma on FDG PET/CT scans has not been previously demonstrated. We hypothesized that a voxel-based analysis of the iliac bones on the FDG PET/CT scan might provide insight into bone marrow involvement.

PATIENTS AND METHODS

A retrospective cohort study of patients with a diagnosis of MCL who had undergone both single iliac bone marrow biopsy and FDG-PET/CT scan from 1 study site were included in the development phase (n = 10). An additional 12 patients from a second institution were included in the validation phase. Using a semiautomated workflow, a voxel-based data set of FDG uptake within the bilateral iliac bones was captured for each patient. In the development phase, empirical receiver operating characteristic curves for each data set were fit. We then identified the standardized uptake value (SUV) threshold cutpoints at which the sensitivity and specificity were optimized to 100%. In the validation phase, we evaluated the performance of these candidate SUV threshold cutpoints in 15 additional patients from a second institution.

RESULTS

We found that 1 cutpoint, > 38% of voxels with activity < 0.95, outperformed all the other candidate cutpoints, correctly classifying all patients except for 1 (overall sensitivity, 100%; specificity, 87.5%).

CONCLUSION

The ability to correctly identify bone marrow involvement using FDG PET/CT-based voxel analysis provides promise as a novel noninvasive method of accurate staging.

Can diffusion-weighted whole-body MRI replace contrast-enhanced CT for initial staging of Hodgkin lymphoma in children and adolescents?

BACKGROUND

Although positron emission tomography with 18F-fluoro-2-deoxyglucose (FDG-PET/CT) has been recommended as the method of choice for lymphoma staging, it has limited availability in several countries, therefore, studies comparing whole-body magnetic resonance imaging (MRI) to conventional staging methods or to FDG-PET/CT are an important tool to establish whole-body MRI as an alternative to these methods.

OBJECTIVE

To compare whole-body MRI versus conventional imaging methods for staging of Hodgkin lymphoma in children and adolescents.

MATERIALS AND METHODS

The study included 22 patients ages 5 to 21 years. Staging was performed using conventional imaging methods and whole-body MRI. Conventional imaging methods were defined as computed tomography (CT) of the neck, chest, abdomen and pelvis and ultrasonography of the neck and/or abdomen. We calculated the sensitivity of these methods for Hodgkin lymphoma staging and their sensitivity and specificity for detecting sites of nodal and extranodal involvement.

RESULTS

The sensitivity of whole-body MRI for Hodgkin lymphoma staging was superior to that of conventional imaging methods (95.5% vs. 86.4%, respectively), but both methods had similar sensitivity and specificity for detecting involvement of nodal sites (99.1% and 100% vs. 97.3% and 100%, respectively) and extranodal sites (90.5% and 98.7% vs. 90.5% and 99.4%, respectively).

CONCLUSION

Whole-body MRI has excellent sensitivity for staging of Hodgkin lymphoma in children and adolescents. It can thus be considered an alternative for this purpose, particularly because it does not expose patients to ionizing radiation.

Whole Body MRI and oncology: recent major advances

MRI is a very attractive approach for tumour detection and oncological staging with its absence of ionizing radiation, high soft tissue contrast and spatial resolution. Less than 10 years ago the use of Whole Body MRI (WB-MRI) protocols was uncommon due to many limitations, such as the forbidding acquisition times and limited availability. This decade has marked substantial progress in WB-MRI protocols. This very promising technique is rapidly arising from the research world and is becoming a commonly used examination for tumour detection due to recent technological developments and validation of WB-MRI by multiple studies and consensus papers. As a result, WB-MRI is progressively proposed by radiologists as an efficient examination for an expanding range of indications. As the spectrum of its uses becomes wider, radiologists will soon be confronted with the challenges of this technique and be urged to be trained in order to accurately read and report these examinations. The aim of this review is to summarize the validated indications of WB-MRI and present an overview of its most recent advances. This paper will briefly discuss how this examination is performed and which are the recommended sequences along with the future perspectives in the field.

Whole Body MRI and oncology: recent major advances

MRI is a very attractive approach for tumour detection and oncological staging with its absence of ionizing radiation, high soft tissue contrast and spatial resolution. Less than 10 years ago the use of Whole Body MRI (WB-MRI) protocols was uncommon due to many limitations, such as the forbidding acquisition times and limited availability. This decade has marked substantial progress in WB-MRI protocols. This very promising technique is rapidly arising from the research world and is becoming a commonly used examination for tumour detection due to recent technological developments and validation of WB-MRI by multiple studies and consensus papers. As a result, WB-MRI is progressively proposed by radiologists as an efficient examination for an expanding range of indications. As the spectrum of its uses becomes wider, radiologists will soon be confronted with the challenges of this technique and be urged to be trained in order to accurately read and report these examinations. The aim of this review is to summarize the validated indications of WB-MRI and present an overview of its most recent advances. This paper will briefly discuss how this examination is performed and which are the recommended sequences along with the future perspectives in the field.

Prognostic Importance of Bone Marrow Uptake on Baseline 18F-FDG Positron Emission Tomography in Diffuse Large B Cell Lymphoma

AIM

To define the role of ¹⁸F-flourodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the detection of bone marrow (BM) involvement in patients with diffuse large B cell lymphoma (DLBCL).

MATERIALS AND METHODS

Fifty-four (mean age: 55.5 ± 18.3 years, 20 female and 34 male) DLBCL patients who underwent pretreatment ¹⁸F-FDG PET/CT were included to the study. Focal or diffuse BM ¹⁸F-FDG uptake that is higher than mediastinal blood pool uptake was accepted as positive. After staging of disease by CT and ¹⁸F-FDG PET/CT, all the patients received R-CHOP treatment after diagnostic blinded bone marrow biopsy (BMB). Presence of positive BM uptake in ¹⁸F-FDG PET/CT and histopathological examination results of BMBs were analyzed by Chi-square test. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of ¹⁸F-FDG PET/CT in the detection of BM involvement were calculated. Prognostic importance of the presence of BM ¹⁸F-FDG uptake was analyzed by Kaplan-Meier analysis.

RESULTS

BM ¹⁸F-FDG uptake was detected in 8 patients. Histopathological examination of BMB revealed BM involvement in 6 out of 8 patients. BMB was negative in all patients who have no ¹⁸F-FDG uptake in the evaluation of PET/CT images. Sensitivity, specificity, accuracy, PPV, and NPV of ¹⁸F-FDG PET/CT in the detection of BM involvement were calculated as 100%, 96%, 96%, 75%, and 100%, respectively. In the Kaplan-Meier analysis, we found that presence of pretreatment ¹⁸F-FDG uptake in BM has a prognostic importance. Whereas mean time to progression (TTP) in patients with BM uptake was 32.25 ± 10.9 months and mean TTP in those without was 51.69 ± 3.6 months (p = 0.013).

CONCLUSIONS

BM uptake in pretreatment ¹⁸F-FDG PET/CT is an important prognostic factor in DLBCL patients. Moreover, in consideration of high NPV, ¹⁸F-FDG PET/CT could eliminate unnecessary BMB in FDG-negative patients.

Whole-body MRI, FDG-PET/CT, and bone marrow biopsy, for the assessment of bone marrow involvement in patients with newly diagnosed lymphoma

PURPOSE

To compare whole-body MRI (WB-MRI) with diffusion-weighted imaging (DWI), FDG-PET/CT, and bone marrow biopsy (BMB), for the evaluation of bone marrow involvement (BMI) in patients with newly diagnosed lymphoma.

MATERIALS AND METHODS

This retrospective study was approved by our Institutional Review Board. Two independent radiologists and one nuclear medicine specialist reviewed all WB-MRI and FDG-PET/CT scans prospectively performed on 104 patients with newly diagnosed lymphoma (53 males; 47 Hodgkin; mean age: 44 years; range, 15-86 years) between 2013 and 2015. The delay between imaging scans and BMBs was up to 10 days. The diagnostic accuracy of WB-MRI (1.5 Tesla MR scanner, with T1w, T2w-STIR, and DWI sequences) was evaluated using BMB and FDG-PET/CT as the reference standard. We applied Cohen's kappa coefficient to assess the inter-observer agreement in WB-MRI interpretation and to compare WB-MRI, FDG-PET/CT and BMB. The Student's t test was done to compare pelvic marrow ADC values of patients with positive and negative BMB. A P-value of < 0.01 was considered significant.

RESULTS

Inter-observer agreement was excellent (k = 0.937). Agreement between WB-MRI and FDG-PET/CT was excellent, with a k = 0.935. Agreement between WB-MRI and BMB was moderate (k = 0.489), and fair between FDG-PET/CT and BMB (k = 0.370). WB-MRI and FDG-PET/CT were falsely negative in four indolent non-Hodgkin lymphomas with BMI < 30% of marrow cellularity. Conversely, WB-MRI and FDG-PET/CT detected all cases with a BMI>30% of marrow cellularity. Mean ADC values in patients with positive and negative BMB were not significantly different (P = 0.049).

CONCLUSION

WB-MRI and FDG-PET/CT are valuable tools for the assessment of BMI.

LEVEL OF EVIDENCE

3 J. Magn. Reson. Imaging 2017;45:1082-1089.

(18) F-FDG PET-CT and trephine biopsy assessment of bone marrow involvement in lymphoma

The ability of positron emission tomography-computerized tomography (PET-CT) to accurately detect bone marrow involvement (BMI) has been suggested in Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL), but its abilities in other histologies is less established. The aim of this retrospective study was to confirm the role of PET-CT in detecting BMI in DLBCL and HL, and to explore its usefulness in other subtypes. Of the 149 newly diagnosed patients, common subtypes included DLBCL, follicular lymphoma (FL) and HL. In DLBCL, the sensitivity and specificity of PET-CT at diagnosis were 75% and 92%. In FL, the sensitivity and specificity of PET-CT were 67% and 85% at diagnosis, and 73% and 89% at relapse. In HL, the sensitivity and specificity were 100% and 74%. PET-CT was able to detect BMI in patients with negative biopsies. Most of the patients in which PET-CT failed to identify BMI were already advanced stage by imaging. In this analysis, PET-CT was highly accurate for detecting BMI at diagnosis in DLBCL and HL and highly specific in FL at diagnosis and relapse. Results also suggested the diagnostic advantage of PET-CT over bone marrow biopsy in detecting BMI. Prospective evaluation is necessary and may eliminate biopsies in future patients.

Bone marrow 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography cannot replace bone marrow biopsy in diffuse large B-cell lymphoma

This study aimed to investigate whether visual and quantitative (18) F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT)-based bone marrow assessment can replace blind bone marrow biopsy (BMB) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). This retrospective study included 78 patients with newly diagnosed DLBCL who had undergone both FDG-PET/CT and BMB. FDG-PET/CT images were visually evaluated for bone marrow involvement. Patient-based sensitivity of visual FDG-PET/CT assessment was calculated using BMB as the reference standard. Metabolically active volume, maximum standardized uptake value, 3D partial volume corrected mean standardized uptake value, and 3D partial volume corrected mean metabolic volume product (cMVPmean ) of FDG-avid bone marrow lesions were measured. Cox regression analysis was used to determine the influence of (potential) prognostic factors (BMB status, visual [dichotomous] FDG-PET/CT bone marrow status, metabolically active volume, maximum standardized uptake value, 3D partial volume corrected mean standardized uptake value, 3D partial volume corrected mean metabolic volume product, and International Prognostic Index score) on progression-free survival and overall survival. FDG-PET/CT detected bone marrow involvement in 34 (43.6%) cases and BMB in 16 (20.5%) of 78 cases, of whom 11 were also detected by FDG-PET/CT, resulting in a patient-based sensitivity of 68.8% (95% confidence interval = 44.2%-86.1%) for FDG-PET/CT. In the multivariate Cox proportional hazards model, only BMB status was an independent predictive factor of progression-free survival (P = 0.016) and overall survival (P = 0.004). In conclusion, FDG-PET/CT misses bone marrow involvement that has been detected by BMB in a non-negligible proportion of patients. Furthermore, both visual and quantitative FDG-PET/CT-based bone marrow assessments are prognostically inferior to BMB. Therefore, FDG-PET/CT cannot replace BMB in newly diagnosed DLBCL.

Whole-body MRI for initial staging of paediatric lymphoma: prospective comparison to an FDG-PET/CT-based reference standard

OBJECTIVE

To compare whole-body MRI, including diffusion-weighted imaging (whole-body MRI-DWI), with FDG-PET/CT for staging newly diagnosed paediatric lymphoma.

METHODS

A total of 36 children with newly diagnosed lymphoma prospectively underwent both whole-body MRI-DWI and FDG-PET/CT. Whole-body MRI-DWI was successfully performed in 33 patients (mean age 13.9 years). Whole-body MRI-DWI was independently evaluated by two blinded observers. After consensus reading, an unblinded expert panel evaluated the discrepant findings between whole-body MRI-DWI and FDG-PET/CT and used bone marrow biopsy, other imaging data and clinical information to derive an FDG-PET/CT-based reference standard.

RESULTS

Interobserver agreement of whole-body MRI-DWI was good [all nodal sites together (κ = 0.79); all extranodal sites together (κ = 0.69)]. There was very good agreement between the consensus whole-body MRI-DWI- and FDG-PET/CT-based reference standard for nodal (κ = 0.91) and extranodal (κ = 0.94) staging. The sensitivity and specificity of consensus whole-body MRI-DWI were 93 % and 98 % for nodal staging and 89 % and 100 % for extranodal staging, respectively. Following removal of MRI reader errors, the disease stage according to whole-body MRI-DWI agreed with the reference standard in 28 of 33 patients.

CONCLUSIONS

Our results indicate that whole-body MRI-DWI is feasible for staging paediatric lymphoma and could potentially serve as a good radiation-free alternative to FDG-PET/CT.

KEYPOINTS

• Accurate staging is important for treatment planning and assessing prognosis • Whole-body MRI-DWI could be a good radiation-free alternative to FDG-PET/CT • Interobserver agreement of whole-body MRI-DWI is good • Agreement between whole-body MRI and the FDG-PET/CT reference standard is good • Most discrepancies were caused by suboptimal accuracy of size measurements on MRI.

Systematic review and meta-analysis on the diagnostic performance of FDG-PET/CT in detecting bone marrow involvement in newly diagnosed Hodgkin lymphoma: is bone marrow biopsy still necessary?

BACKGROUND

This study aimed to systematically review and meta-analyze published data on the diagnostic performance of (18)F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) in detecting bone marrow involvement in newly diagnosed Hodgkin lymphoma, and to determine whether FDG-PET/CT can replace blind bone marrow biopsy (BMB) in these patients.

PATIENTS AND METHODS

The PubMed/Medline and Embase databases were systematically searched for relevant studies. Methodological quality of each study was assessed. Sensitivities and specificities of FDG-PET/CT in individual studies were calculated and underwent meta-analysis with a random effects model. A summary receiver operating characteristic curve (sROC) was constructed with the Moses-Shapiro-Littenberg method. The weighted summary proportion of FDG-PET/CT-negative patients with a positive BMB among all cases was calculated under the fixed effects model.

RESULTS

Nine eligible studies, comprising a total of 955 patients with newly diagnosed Hodgkin lymphoma, were included. Overall, the studies were of moderate methodological quality. The sensitivity and specificity of FDG-PET/CT for the detection of bone marrow involvement ranged from 87.5% to 100% and from 86.7% to 100%, respectively, with pooled estimates of 96.9% [95% confidence interval (CI) 93.0% to 99.0%] and 99.7% (95% CI 98.9% to 100%), respectively. The area under the sROC curve was 0.9860. The weighted summary proportion of FDG-PET/CT-negative patients with a positive BMB among all cases was 1.1% (95% CI 0.6% to 2.0%).

CONCLUSION

Although the methodological quality of studies that were included in this systematic review and meta-analysis was moderate, the current evidence suggests that FDG-PET/CT may be an appropriate method to replace BMB in newly diagnosed Hodgkin lymphoma.

Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET

OBJECTIVE

To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma.

METHODS

A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately.

RESULTS

Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8-62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3-100 %)] was significantly higher (P = 0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1-47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8-98.9 %)] was also significantly higher (P = 0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0-49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P = 1.00) CONCLUSION: Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities.

KEY POINTS

• Bone marrow involvement in lymphoma has prognostic and therapeutic implications. • Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. • Neither whole-body MRI nor FDG-PET can yet replace BMB. • Both techniques have higher sensitivity in aggressive than in indolent lymphoma. • Both imaging techniques are complementary to BMB.

SUV on dual-phase FDG PET/CT correlates with the Ki-67 proliferation index in patients with newly diagnosed non-Hodgkin lymphoma

PURPOSE

PET using 18F-FDG integrated with CT is beneficial for staging patients with non-Hodgkin lymphoma (NHL). The Ki-67 index is used to assess the proliferation potential of tumor cells. The aim of this study was to evaluate the correlation of the Ki-67 index in tissue samples with the SUV at different sites on dual-phase FDG PET/CT of patients with newly diagnosed NHL.

MATERIALS AND METHODS

From September 2009 to March 2011, patients with newly diagnosed NHL who had received dual-phase FDG PET/CT for staging and biopsy samples that were evaluated for the Ki-67 expression were enrolled. The SUVmax of the biopsy site, the tumorous lesion sites, and 3 different bone marrow sites (right iliac crest, sternum, and L1) were measured. The SUVmean of the liver and spleen were also measured.

RESULTS

There were a total of 27 patients in this study. Significant correlations were observed between the Ki-67 index and the SUVmax of the right iliac crest in patients with early-stage disease (stage I and II) patients, the SUVmax of the biopsy and whole-body lesion sites in patients with late-stage disease (stage III and IV), and the retention index of SUVmax of the right iliac crest in patients whose bone marrow were involved by lymphoma cells.

CONCLUSIONS

For patients with newly diagnosed NHL, the significant correlation between the Ki-67 index and the SUV in this study suggests that dual-phase FDG PET/CT may be used as a noninvasive measurement of tumor proliferation.

A systematic approach to magnetic resonance imaging evaluation of epiphyseal lesions

Magnetic Resonance Imaging (MRI) is the preferred modality of choice to image epiphyseal lesions. It provides excellent soft tissue resolution and extent of disease. A wide spectrum of tumor and tumor like lesions can involve the epiphysis. Early and accurate diagnosis as well as appropriate management of epiphyseal lesions is critical as these conditions may lead to disabling complications such as, limb length discrepancy, angular or joint surface deformities and secondary osteoarthritis. In this article, we discuss the role of conventional sequences, such as T1W, fluid sensitive T2W and intravenous (IV) Gadolinium enhanced sequences as well as the additional value of problem solving MRI sequences such as, chemical shift and diffusion weighted imaging. Based on the imaging findings on various MRI sequences and lesion characteristics, a systematic approach directed to the diagnoses of epiphyseal lesions is presented and discussed. MRI features of clinically and biopsy proven examples of the epiphyseal lesions, such as osteomyelitis, intra-osseous abscess, infiltrative malignancy, metastases, transient osteoporosis, subchondral insufficiency fracture, avascular necrosis, osteochondral fracture, osteochondritis dissecans, eosinophilic granuloma and geode are demonstrated. Using this systematic approach, the reader will be able to better characterize epiphyseal lesions with a potential to positively affect patient management.

Usefulness of (18)F-FDG PET/CT for the Evaluation of Bone Marrow Involvement in Patients with High-Grade Non-Hodgkin's Lymphoma

PURPOSE

To assess the usefulness of (18)F-fluorodeoxyglucose PET/CT in the detection of bone marrow (BM) involvement of high-grade non-Hodgkin's lymphoma (NHL).

METHODS

One hundred twenty patients with newly diagnosed diffuse large B-cell lymphoma or peripheral T-cell lymphoma between January 2007 and June 2011, who received BM trephine biopsy and (18)F-FDG PET/CT before chemotherapy, were included in this retrospective study. We reviewed their (18)F-FDG PET/CT images and bone marrow biopsy (BMB) results. After reviewing the images, we reviewed the medical records and radiological findings of interesting patients.

RESULTS

There were 23 (18)F-FDG PET/CT scans in which the marrow was considered to be abnormal (either positive or equivocal), and 97 (18)F-FDG PET/CT scans were regarded as having negative FDG uptake. Of 120 patients, 100 (83.3 %) had a concordant result of BM interpretation between (18)F-FDG PET/CT and BMB, and the remaining 20 patients had discordant results. Among 23 patients with either positive or equivocal (18)F-FDG PET/CT scans, 1 of 12 patients with 'positive' (18)F-FDG PET/CT had a lymphomatous involvement on BMB. In contrast, 10 of 11 patients with 'equivocal' BM hypermetabolism were reported as having positive involvement by BMB. Patients with abnormal (18)F-FDG PET/CT had significantly higher mSUVhighest than those with normal FDG-PET/CT.

CONCLUSIONS

(18)F-FDG PET/CT and BMB are complementary techniques in assessing the presence of BM involvement in patients with high-grade NHL. The increasing availability of (18)F-FDG PET/CT will raise the need for additional biopsy for FDG-avid lesions, especially in patients with negative standard BMBs. (18)F-FDG PET/CT can be useful as a decision-making tool for determining whether to perform a standard BMB or targeted biopsy to the FDG-avid lesion as an initial staging procedure. A direct bone biopsy for FDGpositive bone lesions should be included in staging guidelines in future. In (18)F-FDG PET/CT-negative cases, BMB is still a powerful procedure, but BMB alone is insufficient for full evaluation of BM.

Role of Structural Imaging in Lymphoma

The lymphomas, Hodgkin lymphoma and non-Hodgkin lymphoma, are among the most common types of cancer in the United States. Imaging plays an important role in the evaluation of patients with lymphoma, because it aids in treatment planning and in the determination of prognosis. Structural imaging entails the assessment of morphologic features of normal tissues and organs of the body and of malignant lesions within these structures, and plays a major role in the noninvasive assessment of lymphoma. This article reviews cross-sectional structural imaging modalities with an emphasis on computed tomography and magnetic resonance imaging, with some mention of ultrasonography.

18F-FDG PET, combined FDG-PET/CT and MRI for evaluation of bone marrow infiltration in staging of lymphoma: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Evaluation of bone marrow infiltration is an essential step in the staging of lymphoma. The accuracy of (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG PET), combined (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG-PET/CT) and magnetic resonance imaging (MRI) in diagnosing bone marrow involvement of lymphoma has never been systematically assessed, and the present systematic review was aimed at this issue.

METHODS

MEDLINE, EMBASE, Cochrane library and some other databases, from January 1995 to July 2010, were searched for initial studies. All the studies published in English or Chinese relating to the diagnostic value of (18)F-FDG PET, PET/CT and MRI for patients with bone marrow involvement of lymphoma were collected. We extracted data to calculate sensitivity, specificity, SROC curves and AUC and to test for heterogeneity. The statistic software called "Meta-Disc 1.4" was used for data analysis.

RESULT

In 32 included studies, PET/CT had the highest pooled sensitivity, 91.6% (95%CI: 85.1, 95.9) and highest pooled specificity, 90.3% (95%CI: 85.9, 93.7). PET/CT also had the highest pooled DOR, 68.89 (95%CI: 15.88, 298.92). The AUC of PET, PET/CT, and MRI were 0.9430, 0.9505 and 0.8764. There was heterogeneity among studies and no evidence of publication bias.

CONCLUSION

PET/CT was a highly sensitive and specific modality in diagnosing patients with bone marrow involvement in lymphoma. Compared with MRI and PET alone, PET/CT can play important roles in the staging of lymphoma.

Follicular Lymphoma in Staging Bone Marrow Specimens: Correlation of Histologic Findings With the Results of Flow Cytometry Immunophenotypic Analysis

Context.—Bone marrow (BM) examination is part of the staging workup of lymphoma patients. Few studies have compared BM histologic findings with results of flow cytometric immunophenotyping analysis in follicular lymphoma (FL) patients.

Objective.—To correlate histologic findings with immunophenotypic data in staging BM biopsy and aspiration specimens of FL patients.

Design.—Bone marrow biopsy specimens of untreated FL patients were reviewed. Histologic findings were correlated with 3-color flow cytometric immunophenotyping results on corresponding BM aspirates.

Results.—Bone marrow biopsy specimens (with or without aspirates) of 114 patients with histologic evidence of FL in BM were reviewed. There were 76 bilateral and 38 unilateral biopsies performed, resulting in 190 specimens: 187 involved by FL and 3 negative (in patients with a positive contralateral specimen). The extent of BM involvement was &lt;5% in 32 (17.1%), ≥5% and ≤25% in 102 (54.6%), &gt;25% and ≤50% in 27 (14.4%), and &gt;50% in 26 (13.9%) specimens. The pattern of involvement was purely paratrabecular in 81 (43.3%), mixed in 80 (42.8%), and purely nonparatrabecular in 26 (13.9%). Immunophenotyping was only performed unilaterally, on BM aspirates of 92 patients, and was positive for a monoclonal B-cell population in 53 (57.6%) patients. Immunophenotyping was more often negative when biopsy specimens showed FL with a purely paratrabecular pattern. For comparison, we assessed 163 FL patients without histologic evidence of FL in BM also analyzed by flow cytometric immunophenotyping. A monoclonal B-cell population was identified in 5 patients (3%).

Conclusions.—Our data suggest that 3-color flow cytometric immunophenotyping adds little information to the evaluation of staging BM specimens of FL patients.

Can [18F]fluorodeoxyglucose positron emission tomography imaging complement biopsy results from the iliac crest for the detection of bone marrow involvement in patients with malignant lymphoma?

OBJECTIVES

To assess the usefulness of [18F]fluorodeoxyglucose positron emission tomography in the detection of bone marrow involvement in malignant lymphoma, and its impact in clinical management.

METHODS

One hundred and six consecutive patients with a confirmed diagnosis of lymphoma, referred for staging or restaging of Hodgkin's lymphoma (n=18) or non-Hodgkin's lymphoma (n=88), were reviewed retrospectively. A positron emission tomography scan and bone marrow biopsy of the iliac crest were performed in all patients. The assessment of bone marrow involvement by lymphoma was confirmed by histology and/or progression of bone marrow lesions in clinical follow-up.

RESULTS

In 28 of 106 patients, bone marrow involvement was found. Positron emission tomography was more sensitive (86%) than bone marrow biopsy (57%). Positron emission tomography and bone marrow biopsy were concordant by positive correlation in 12 of 28 cases (43%) and by negative correlation in 77 of 78 cases (99%). Ten cases of non-Hodgkin's lymphoma and two cases of Hodgkin's lymphoma with positive positron emission tomography results and an initial negative bone marrow biopsy showed clinical progression of the bone marrow lesions and/or subsequent positive histology. These were considered as false-negative results for bone marrow biopsy. In seven of the 12 positive cases with negative bone marrow biopsy, positron emission tomography uptake distant from the site of the biopsy was seen. In four cases of follicular lymphoma, the bone marrow biopsy was positive and the positron emission tomography scan was normal.

CONCLUSIONS

Positron emission tomography and bone marrow biopsy are complementary in assessing the presence of bone marrow involvement in patients with malignant lymphoma. In our series, positron emission tomography was more sensitive than bone marrow biopsy in Hodgkin's and non-Hodgkin's lymphoma, except in follicular lymphoma.

Role of 99mTc-hexakis-2-methoxyisobutylisonitrile for detecting marrow metastases in childhood solid tumours

AIM

To evaluate the role of 99mTc-hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) for detecting bone marrow metastases in childhood solid tumours, including lymphomas.

METHODS

Twenty-six children (18 males, eight females) were studied. They all had proven malignant solid tumours [Hodgkin's lymphoma (5), non-Hodgkin's lymphoma (3), neuroblastoma (9), Ewing's sarcoma (3), Langerhans cell histiocytosis (4), rhabdomyosarcoma (1) and germ cell tumour (1)] with suspected bone marrow metastases. All patients underwent computed tomography and/or magnetic resonance imaging, 99mTc-MIBI and Tc-methylene diphosphonate bone scans and bone marrow aspiration and/or biopsy. The scintigraphic evaluation of 99mTc-MIBI scans was performed according to the visual assessment of the extent and intensity of uptake. The scintigraphic score, which is the sum of the extent and intensity of uptake, was calculated for each patient. Scores of more than 2 were considered to be positive for bone marrow involvement.

RESULTS

Twenty-seven 99mTc-MIBI scans were studied for 26 patients. Twenty-two 99mTc-MIBI scans were accepted as normal bone marrow. Bone scans were also normal in these patients. Five of the 27 99mTc-MIBI scans had scores of more than 2. Bone marrow cytology revealed bone marrow metastases in these patients.

CONCLUSION

Abnormal 99mTc-MIBI uptake correlated extremely well with bone marrow aspiration/biopsy cytology results. Non-invasive 99mTc-MIBI imaging in children with malignant solid tumours appears to be promising for the evaluation of bone marrow metastases.

A pathologist's perspective on bone marrow aspiration and biopsy: I. Performing a bone marrow examination

The bone marrow aspirate and biopsy is an important medical procedure for the diagnosis of hematologic malignancies and other diseases, and for the follow-up evaluation of patients undergoing chemotherapy, bone marrow transplantation, and other forms of medical therapy. During the procedure, liquid bone marrow is aspirated from the posterior iliac crest or sternum with a special needle, smeared on glass microscope slides by one of several techniques, and stained by the Wright-Giemsa or other techniques for micro-scopic examination. The bone marrow core biopsy is obtained from the posterior iliac crest with a Jamshidi or similar needle and processed in the same manner as other surgical specimens. Flow cytometric examination, cytochemical stains, cytogenetic and molecular analysis, and other diagnostic procedures can be performed on bone marrow aspirate material, while sections prepared from the bone marrow biopsy can be stained by the immunoperoxidase or other techniques. The bone marrow procedure can be performed with a minimum of discomfort to the patient if adequate local anesthesia is utilized. Pain, bleeding, and infection are rare complications of the bone marrow procedure performed at the posterior iliac crest, while death from cardiac tamponade has rarely occurred from the sternal bone marrow aspiration. The recent development of bone marrow biopsy needles with specially sharpened cutting edges and core-securing devices has reduced the discomfort of the procedure and improved the quality of the specimens obtained.

Prospective analysis of minimal bone marrow infiltration in pediatric Burkitt's lymphomas by long-distance polymerase chain reaction for t(8;14)(q24;q32)

The chromosomal translocation t(8;14)(q24;q32) represents a characteristic marker for Burkitt's lymphoma (BL). This translocation involves the MYC oncogene on chromosome 8 and the immunoglobulin heavy-chain (IgH) locus on chromosome 14. Since the translocation does not produce a fusion gene, we established a long-distance polymerase chain reaction (LD-PCR) assay that can detect the t(8;14) at the genomic level. The sensitivity of the LD-PCR was 10(-4). We used the LD-PCR assay to prospectively study 78 BL patients and found a specific PCR product in 52 of them. Among the 52 positive patients, we could test both the tumor and the bone marrow (BM) at diagnosis in 33 and determined the prevalence of minimal disseminated disease (MDD) at diagnosis. In 12/33 patients, BM was positive by LD-PCR and in 10 of them we conducted a study of minimal residual disease (MRD). Eight out of 10 children showed a clearance of MRD after one cycle of chemotherapy. The only two patients who did not achieve a negative MRD status died of disease progression. The comparative analysis of sensitivity of BM aspirate, BM biopsy and LD-PCR in t(8;14)-positive patients demonstrated a superiority of the molecular method in the assessment of MDD. The LD-PCR for t(8;14) is an important tool to study minimal BM infiltration at diagnosis and to determine its response kinetics in BL.

Diagnostic utility of bilateral bone marrow examination: significance of morphologic and ancillary technique study in malignancy

BACKGROUND

To retrospectively evaluate the significance of morphologic examination and ancillary studies performed on bilateral bone marrow biopsy specimens, 1864 bone marrow samples were studied.

METHODS

Bilateral bone marrow biopsy specimens included 883 specimens that were evaluated for involvement by non-Hodgkin lymphoma (NHL); 381 specimens that were evaluated for involvement by carcinoma (CA); 362 specimens that were evaluated for involvement by Hodgkin disease (HD); 94 specimens that were evaluated for involvement by sarcoma (SA); 56 specimens that were evaluated for involvement by multiple myeloma (MM); 53 specimens that were evaluated for involvement by acute and chronic leukemia, myelodysplasia, and/or myeloproliferative disorders (LEUK); and 35 specimens that were evaluated for other reasons.

RESULTS

Of all 1864 specimens, 410 samples (22.0%) were positive for disease, including 77% of MM samples, 58% of LEUK samples, 29.6% of NHL samples, 14% of SA samples, 9.9% of HD samples, and 6.8% of CA samples. A discrepancy between the left and right sides was identified in 48 specimens (11.7% of positive samples). The discrepancy rate was 39% for HD samples, 29% for SA samples, 23% for CA samples, and 9.2% for NHL samples. No morphologic discrepancies between bilateral samples were found in MM samples or LEUK samples. Bilateral flow cytometric studies (n = 113 samples) were positive in 11 samples (9.7%; all morphologically positive), with two discrepancies detected between bilateral samples. Bilateral cytogenetic studies (n = 74 samples) were positive in 5 samples (7%), and there were no discrepancies. Bilateral molecular studies (n = 16 samples) were positive in 7 samples (44%), and there were 3 discrepancies.

CONCLUSIONS

Bilateral morphologic evaluation is useful in the evaluation of patients with NHL, HD, CA, and SA and is not indicated for patients with acute or chronic leukemia, myelodysplasia, MM, and other diseases. Bilateral flow cytometric or cytogenetic studies of bone marrow did not provide additional information in this population to justify bilateral samples. The role of bilateral molecular analysis needs to be defined further, but pooled samples for molecular studies may be adequate.

Bone marrow trephine biopsy

Trephine biopsies of the bone marrow should be carried out, when clinically indicated, by trained individuals following a standard operating procedure. A bone marrow aspiration should be performed as part of the same procedure. For patient safety and convenience, biopsies are usually performed on the posterior iliac crest. The biopsy specimen should measure at least 1.6 cm and, if it does not, consideration should be given to repeating the procedure, possibly on the contralateral iliac crest. If bone marrow aspiration is found to be impossible, imprints from the biopsy specimen should be obtained. Otherwise, the specimen is placed immediately into fixative and after fixation is embedded in a resin or, more usually, decalcified and embedded in paraffin wax. Thin sections are cut and are stained, as a minimum, with haematoxylin and eosin and with a reticulin stain. A Giemsa stain is also desirable. A Perls' stain does not often give useful information and is not essential in every patient. The need for other histochemical or immunohistochemical stains is determined by the clinical circumstances and the preliminary findings. Trephine biopsy sections should be examined and reported in a systematic manner, assessment being made of the bones, the vessels and stroma, and the haemopoietic and any lymphoid or other tissue. Assessment should begin with a very low power objective, the entire section being examined. Further examination is then done with an intermediate and high power objective. Ideally, reporting of trephine biopsy sections should be done by an individual who is competent in both histopathology and haematology, and who is able to make an appropriate assessment of both the bone marrow aspirate and the trephine biopsy sections. When this is not possible, there should be close consultation between a haematologist and a histopathologist. The report should both describe the histological findings and give an interpretation of their importance. A signed or computer authorised report should be issued in a timely manner. If the report is a preliminary, this must be clearly stated.

Diagnosis of bone marrow metastases in children with solid tumors and lymphomas. Aspiration, or unilateral or bilateral biopsy?

BACKGROUND

Malignancies are among the most common causes of death in children. The present study was undertaken to evaluate and compare bone marrow aspiration and unilateral biopsy to detect bone marrow metastases in pediatric patients, using bilateral biopsy as the gold standard.

METHODS

During a 6-month period, 63 consecutive newly diagnosed children with confirmed malignant diseases other than leukemia were evaluated for bone marrow metastases or infiltration. Biopsies were obtained from both right and left posterior iliac crests whereas aspiration was performed only at the right crest. Interpretation to the right-side biopsy was considered as the unilateral biopsy result, whereas the bilateral biopsy result was as follows: positively was accepted if one or both of the two-side samples were qualified as positive, while a negative result was considered only if both sides were negative. The bilateral biopsy was considered the gold standard, and sensitivity, specificity, positive and negative predictive value, and false positive and negative rates were computed for the unilateral biopsy and aspiration procedure.

RESULTS

We identified bone marrow metastases in 11 (17.5%) patients. The sensitivity was the only significant difference (p <0.05) observed between unilateral biopsy and aspiration. Finally, of the 63 patients, unilateral biopsy was reported as inadequate in one patient (1.6%), while aspiration was inadequate in two (3.2%).

CONCLUSION

Unilateral biopsy was better than bone marrow aspiration. However, because bilateral biopsy is the gold standard, we recommend using this and bone marrow aspiration simultaneously to evaluate a pediatric patient with any malignancy potentially infiltrating bone marrow.

Detection of Lymphoma in Bone Marrow by Whole-Body Positron Emission Tomography

Positron emission tomography (PET) is a whole-body imaging technique using 18 fluorine-fluorodeoxyglucose (FDG), whose uptake is increased in tumor cells. Published studies have shown PET to be an effective method of staging lymphoma and to be more sensitive than CT at detecting extranodal disease. The purpose of this study was to determine whether the increased marrow uptake of FDG observed in some lymphoma patients during routine staging PET scans represented marrow involvement by disease. PET scans of 50 patients with Hodgkin's (12) and non-Hodgkin's (38) lymphoma were analyzed by three independent observers and the marrow graded as normal or abnormal using a visual grading system. Unilateral iliac crest marrow aspirates and biopsies were performed on all patients. The PET scan and marrow histology agreed in 39 patients (78%), being concordant positive in 13 and concordant negative in 26 patients. In 8 patients the PET scan showed increased FDG uptake but staging biopsy was negative; in 4 of these 8 patients the PET scan showed a normal marrow background with focal FDG “hot spots” distant from the site biopsied. In 3 patients the marrow biopsy specimen was positive but the PET scan normal; 2 of these 3 patients had non-Hodgkin's lymphoma whose malignant cells did not take up FDG at lymph node or marrow disease sites. Therefore, there were only 5 patients (10%) in whom there was a difference between the PET scan and biopsy result which could not be fully explained. Visual interpretation of marrow FDG uptake during whole-body staging PET scans can correctly assess marrow disease status in a high proportion of lymphoma patients. PET has the potential to reduce the need for staging marrow biopsy.

Detection of Lymphoma in Bone Marrow by Whole-Body Positron Emission Tomography

Positron emission tomography (PET) is a whole-body imaging technique using 18 fluorine-fluorodeoxyglucose (FDG), whose uptake is increased in tumor cells. Published studies have shown PET to be an effective method of staging lymphoma and to be more sensitive than CT at detecting extranodal disease. The purpose of this study was to determine whether the increased marrow uptake of FDG observed in some lymphoma patients during routine staging PET scans represented marrow involvement by disease. PET scans of 50 patients with Hodgkin's (12) and non-Hodgkin's (38) lymphoma were analyzed by three independent observers and the marrow graded as normal or abnormal using a visual grading system. Unilateral iliac crest marrow aspirates and biopsies were performed on all patients. The PET scan and marrow histology agreed in 39 patients (78%), being concordant positive in 13 and concordant negative in 26 patients. In 8 patients the PET scan showed increased FDG uptake but staging biopsy was negative; in 4 of these 8 patients the PET scan showed a normal marrow background with focal FDG “hot spots” distant from the site biopsied. In 3 patients the marrow biopsy specimen was positive but the PET scan normal; 2 of these 3 patients had non-Hodgkin's lymphoma whose malignant cells did not take up FDG at lymph node or marrow disease sites. Therefore, there were only 5 patients (10%) in whom there was a difference between the PET scan and biopsy result which could not be fully explained. Visual interpretation of marrow FDG uptake during whole-body staging PET scans can correctly assess marrow disease status in a high proportion of lymphoma patients. PET has the potential to reduce the need for staging marrow biopsy.

Non-Hodgkin's lymphoma

Pediatric lymphomas are the third most common group of malignancies in children and adolescents. Unlike lymphomas in adults, pediatric lymphomas are diffuse, aggressive neoplasms with a propensity for widespread dissemination. Intensification of conventional treatment approaches along with improvements in supportive care have resulted in dramatic improvement in event-free survival rates of close to 90% in patients with B-cell lymphomas and only slightly lower in patients with T-cell lymphomas. Lymphoid neoplasms arise because of genetic changes that result in altered growth and differential patterns of lymphoid cells. The characterization of these molecular abnormalities and an understanding of their consequences has led to new approaches to diagnosis and the detection of minimal residual disease and also provides the basis for the future development of novel treatment approaches targeted specifically to the neoplastic cells.

Immunophenotypic analysis of T-cell acute lymphoblastic leukaemia in Madras, India

Immunophenotypic analysis of 285 newly diagnosed previously untreated, unselected, acute lymphoblastic leukaemia cases carried out at the Cancer Institute (W.I.A) in Madras reveals that 126 (44.2%) cases showed T-immunophenotype. The study was conducted using flow-cytometric immunofluorescent or immunoperoxidase methods using an extensive panel of monoclonal antibodies comprising CD1, 2, 3, 4, 5, 7, 8, 57, 19, 20 kappa, lambda, IgG, M, D, CIg, CD10, HLA-DR, CD13, 14, 33, 34 and CD61. The study group comprised 73 (57.9%) paediatric cases (<15 years) and 53 (42.1%) adult cases (>15 years). Based on their reactivity with various anti-T-cell monoclonal antibodies, all T-ALL cases were assigned to one of the intrathymic differentiation compartments. 56.2% of paediatric T-ALLs arise from intrathymic compartment II, 34.2% from compartment III and 9.6% from compartment I. Among adults, 45.3% arise from compartment I. 33.9% from compartment III and 20.8% from compartment II. The most frequently observed CD antigens in our study group are CD7, 5, 2 and 3. A correlative study of socioeconomic status reveals that 67.5% of T-ALL cases occurred among lower socioeconomic strata.

[Research on bone marrow involvement in the diagnosis of solid tumors in children. Methods, results and interpretation]

The assessment of bone marrow involvement by tumor cells remains an essential problem at diagnosis in pediatric solid tumors. Besides the conventional cytological and histological methods, some modern cell density separation techniques have been described in order to improve the detection of minimal or scattered bone marrow involvement. Immunological or genetical (molecular biology) tools can be used for the recognition of separated cells. In terms of investigations, MRI and MIBG radionucleide scan, although giving no definite proof, have the ability to macroscopically study the scattering of bone marrow invasion in the particular case of neuroblastoma. In some pediatric tumors, especially neuroblastomas and non Hodgkin lymphomas, an extensive bone marrow investigation is mandatory at diagnosis. Such an investigation is only necessary in case of particular criteria at diagnosis of Hodgkin's disease, Ewing' sarcomas, rhabdomyosarcomas and retinoblastomas. All other pediatric solid tumors do not need to be investigated in terms of bone marrow involvement at diagnosis, with the exceptions of advanced disseminated disease or if an autologous bone marrow transplantation is planned.

Factors contributing to the prognostic significance of bone marrow involvement in childhood non-Hodgkin lymphoma

To evaluate the clinical characteristics and treatment outcome of childhood non-Hodgkin lymphoma (NHL) cases with bone marrow involvement, we studied 13 lymphoblastic, 15 small noncleaved cell, and 8 large cell cases with tumor cells in their marrow. They represented 16%, 11%, and 9% of consecutive NHL cases with these respective histologic subtypes. The treatment outcome differed significantly according to histologic subtype--the 5-year event-free survivals (EFS +/- SE) for large cell NHL, small non-cleaved cell NHL, and lymphoblastic NHL cases were 11 +/- 8%, 40 +/- 20%, and 62 +/- 15%, respectively. Increased serum lactate dehydrogenase (LDH) levels (> 500 U/L) were associated with a poorer EFS (5-year EFS, 0% vs. 50 +/- 10%; P < 0.001). Children < or = 5 years of age had a poorer EFS survival than older children (5-year EFS, 14 +/- 9% vs. 44 +/- 10%; P = 0.03). The degree of bone marrow involvement (< 5% vs. > or = 5%) and race were not significantly associated with treatment outcome. Although intensive chemotherapy has substantially improved survival for patients with advanced stage lymphoblastic or small noncleaved cell lymphoma, patients with large cell NHL and associated marrow involvement continue to have a dismal outcome and require novel or more intensive therapy.

Treatment of advanced stage T cell lymphoblastic lymphoma: results of the United Kingdom Children's Cancer Study Group (UKCCSG) protocol 8503

Ninety-five unselected patients with stage III and IV T cell lymphoblastic lymphoma were treated according to the United Kingdom Children's Cancer Study Group protocol 8503. This was a continuous, intensive leukaemia type regimen including cranial irradiation (18 Gy in 10 fractions) and continuing chemotherapy for 2 years identical to the concurrent Medical Research Council ALL protocol. Four-year event-free survival was 65% (95% CI 50-80%) with no significant difference between stage III and stage IV cases. 4.2% of patients died of infection or non-tumour related events. Following relapse salvage was unlikely without high dose chemotherapy and bone marrow rescue. These results show an improvement over previous U.K. studies but we need to continue to search for subsets of patients with resistant disease for whom even more intensive therapy possibly combined with bone marrow rescue is required.

Bone marrow involvement in non-Hodgkin's lymphoma: increased diagnostic sensitivity by combination of immunocytology, cytomorphology and trephine histology

Diagnostic results from cytomorphology and immunocytology of aspirated bone marrow (BM) were compared with the findings from standard trephine histology of 100 adult patients with non-leukaemic non-Hodgkin's lymphomas (NHL) in a retrospective study. Immunocytological investigations were performed by the immunoenzymatic APAAP-technique on BM smears monoclonal antibodies against CD19, Cd3, CD10 or TdT antigens and determination of positive cells in relation to total BM leucocytes. Corresponding results were obtained for trephine histology and for the combination of cytomorphology and immunocytology in 93/100 cases. Four cases with BM involvement by trephine histology were missed by the combination of immunocytology and cytomorphology. In turn, three cases negative by trephine histology, were found to be positive by the combination of immunocytology and cytomorphology. Immunocytochemistry considerably increased the number of true positive detected BM-infiltrations by cytomorphology in low grade B-cell lymphoma from 58% to 97%. For the diagnosis of BM involvement in high-grade NHL cytomorphology of the aspirate was of equal sensitivity to the biopsy and was always confirmed by immunocytology. The high diagnostic sensitivity of immunocytology was mainly due to high B-cell counts in BM involved by B-cell lymphoma (means = 38%, s = 23) in contrast to low B-cell counts in BM not involved by NHL (means = 4.5%, s = 3.8). We conclude from our data that immunocytology in addition to standard cytomorphology improves diagnostic sensitivity in the detection of BM involvement by NHL.

Non-Hodgkin's lymphomas in children. I. Patterns of disease and classification

Non-Hodgkin's lymphomas (NHL) are part of an overlapping spectrum of lympho-proliferative diseases in childhood. In the first of this 2 part series, the clinicopathological aspects of NHL in childhood are discussed. The rapid progression of disease, the high incidence of micrometastases (over 80%) at diagnosis, and the propensity of hematogenous spread to the bone marrow and the central nervous system (CNS) as well as the clinico-pathologic 'clusters' associated with particular presenting sites distinguish the pediatric forms of disease. Abdominal primary sites most frequently manifest diffuse undifferentiated (Burkitt's or non-Burkitt's) histopathology, B-cell immunophenotype, FAB-L3 cytomorphology and specific karyotypic and/or genotypic alterations of the immuno-globulin genes and the c-myc oncogene. Mediastinal presentation is associated with lymphoblastic histopathology, T-cell immunophenotype and a variety of less consistent karyotypic and genotypic aberrations. Ki-1 lymphoma, a rare subtype of large cell NHL with specific features is often of T cell origin. The requirements for diagnosis, staging and monitoring are presented in the context of the associations between clinico-pathological presentation and subsequent behavior. The most frequent sites of disease progression and relapse are involvement of the bone marrow and the CNS. For Burkitt's lymphoma there is a historic perspective and a description of particular epidemiologic, clinical, virologic, immunophenotypic and genotypic features. Cytogenetic and molecular biologic studies of genomic rearrangements are advancing the understanding of oncogenesis, clonality, lineage, and clinical behavior. The capacity to detect and amplify DNA from submicroscopic disease may contribute to prognostic stratification both at diagnosis and during subsequent monitoring.