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

Unexpected Symmetrical Uptake of 18 F-FDG of Distal Peripheral Bones in a Patient With Diffuse Large B-Cell Lymphoma

ABSTRACT

A 74-year-old woman was referred for 18 F-FDG PET/CT scanning to investigate an underlining etiology due to recently developed unexplained bone pains and lack of walking capacity. On the initial PET/CT scan, we have noted a highly symmetrical and apparent intramedullary FDG uptake of the distal parts of appendicular skeleton system including the bilateral elbows, wrists, and foot ankles in addition to a lymphadenomegaly in the right groin. The excisional biopsy from the lymph node of right groin revealed a diagnosis of diffuse large B-cell lymphoma.

Coexpression of PD-L1/PD-1 with CXCR3/CD36 and IL-19 Increase in Extranodal Lymphoma

Many studies have demonstrated that PD-L1/PD-1 signaling is an immune evasion mechanism in tumors. PD-L1/PD-1 coexpression with CXCR3/CD36 in peripheral lymphocytes in lymphoma still needs to be clarified. The current study investigated PD-L1/PD-1 coexpression with CXCR3/CD36 in circulating lymphocytes, serum IL-19 levels, and their correlation with clinical outcome and extranodal involvement in lymphoma. Subjects and Methods. The coexpression of PD-L1/PD-1 with CXCR3/CD36 on circulating lymphocytes was analyzed by flow cytometry in 78 lymphoma patients before and after therapy and in 50 healthy controls. The concentration levels of IL-19 in serum were assessed by an ELISA. Results. PD-L1 and PD-1 were expressed on circulating CXCR3+ and CD36+ lymphocytes in lymphoma and were significantly higher in patients with extranodal involvement than in lymphoma patients without extranodal involvement (P < 0.001). Elevated IL-19 levels were observed in lymphoma patients and increased significantly in extranodal involvement (P < 0.001). High percentages of PD-L1+CXCR3+ and PD-1+CXCR3+ lymphocytes were associated with high LDH levels, hepatomegaly, lymphedema, advanced tumor stage, and recurrence. Furthermore, patients with splenomegaly and generalized lymphadenopathy had high percentages of PD-L1+CXCR3+ lymphocytes. In addition, levels of PD-L1/PD-1 coexpression with CXCR3 and IL-19 were significantly associated with bone marrow, lung, and lymph vessel involvement. Further analysis revealed that high percentages of PD-L1+CD36+ and PD-1+CD36+ lymphocytes were associated with lung and bone marrow involvement. Patients with high levels of PD-L1/PD-1 coexpression with CXCR3 and IL-19 had inferior event-free survival (EFS) compared with that in lymphoma patients with low levels. EFS was decreased in patients with high percentages of PD-L1+CD36+ and PD-1+CD36+ lymphocytes. When using the receiver operating characteristic (ROC) curve, the superiority of IL-19 (area under the curve (AUC): 0.993) and PD-L1+CXCR3+% (AUC: 0.961) to PD-1+CXCR3+% (AUC: 0.805), PD-L1+CD36+% (AUC: 0.694), and PD-1+CD36+% (AUC 0.769) was evident in the diagnosis of extranodal involvement, identifying lymphoma patients with extranodal involvement from patients without extranodal involvement. Conclusions. Coexpression of PD-L1/PD-1 with CXCR3/CD36 in circulating lymphocytes and serum IL-19 levels contributes to poor prognosis and might be potential markers for extranodal involvement in lymphoma.

Two-Stage Deep Learning Model for Automated Segmentation and Classification of Splenomegaly

Splenomegaly is a common cross-sectional imaging finding with a variety of differential diagnoses. This study aimed to evaluate whether a deep learning model could automatically segment the spleen and identify the cause of splenomegaly in patients with cirrhotic portal hypertension versus patients with lymphoma disease. This retrospective study included 149 patients with splenomegaly on computed tomography (CT) images (77 patients with cirrhotic portal hypertension, 72 patients with lymphoma) who underwent a CT scan between October 2020 and July 2021. The dataset was divided into a training (n = 99), a validation (n = 25) and a test cohort (n = 25). In the first stage, the spleen was automatically segmented using a modified U-Net architecture. In the second stage, the CT images were classified into two groups using a 3D DenseNet to discriminate between the causes of splenomegaly, first using the whole abdominal CT, and second using only the spleen segmentation mask. The classification performances were evaluated using the area under the receiver operating characteristic curve (AUC), accuracy (ACC), sensitivity (SEN), and specificity (SPE). Occlusion sensitivity maps were applied to the whole abdominal CT images, to illustrate which regions were important for the prediction. When trained on the whole abdominal CT volume, the DenseNet was able to differentiate between the lymphoma and liver cirrhosis in the test cohort with an AUC of 0.88 and an ACC of 0.88. When the model was trained on the spleen segmentation mask, the performance decreased (AUC = 0.81, ACC = 0.76). Our model was able to accurately segment splenomegaly and recognize the underlying cause. Training on whole abdomen scans outperformed training using the segmentation mask. Nonetheless, considering the performance, a broader and more general application to differentiate other causes for splenomegaly is also conceivable.

Utility of F-18 Fluorodeoxyglucose Positron Emission Tomography - Computed Tomography in Primary Thyroid Lymphoma

Primary thyroid lymphoma (PTL) is an uncommon malignancy. The majority of PTLs are non-Hodgkin's lymphoma. Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) is the state-of-the-art imaging in lymphoma and plays a pivotal role in staging, follow-up, and treatment decisions. There is good evidence that it performs well in a wide variety of nodal and extranodal lymphomas (ENL). However, the data are scarce on its usefulness in rare ENL. Herein, we describe four cases of PTLs and a brief review of the literature. FDG PET/CT was performed at baseline to assess the disease status and response to treatment. This case series highlights the varied appearance of PTL and response to treatment. It establishes the importance of FDG PET/CT in the personalized management of PTL.

Radiomics Features of the Spleen as Surrogates for CT-Based Lymphoma Diagnosis and Subtype Differentiation

Simple Summary

In malignant lymphoma an early and accurate diagnosis is essential for therapy initiation and patient outcome. Within the diagnostic process, imaging plays a crucial role in disease staging. However, an invasive biopsy is required for subtype classification. Involvement of the spleen, a major lymphoid organ, is frequent in malignant lymphoma; this may be reactive or due to infiltration by malignant cells. Using radiomics features of the spleen in a machine learning approach, we investigated the possibility of distinguishing malignant lymphoma patients from other cancer patients and to classify lymphoma subtypes in the case of disease presence. Recent studies have proven the value of radiomics analysis in differentiating lymphoma from non-lymphoma groups on involved sites. Supported by machine learning, imaging could gain importance as a noninvasive diagnostic tool for future lymphoma classification, offering more precise radiological information for an interdisciplinary approach regarding treatment planning.

Abstract

The spleen is often involved in malignant lymphoma, which manifests on CT as either splenomegaly or focal, hypodense lymphoma lesions. This study aimed to investigate the diagnostic value of radiomics features of the spleen in classifying malignant lymphoma against non-lymphoma as well as the determination of malignant lymphoma subtypes in the case of disease presence—in particular Hodgkin lymphoma (HL), diffuse large B-cell lymphoma (DLBCL), mantle-cell lymphoma (MCL), and follicular lymphoma (FL). Spleen segmentations of 326 patients (139 female, median age 54.1 +/− 18.7 years) were generated and 1317 radiomics features per patient were extracted. For subtype classification, we created four different binary differentiation tasks and addressed them with a Random Forest classifier using 10-fold cross-validation. To detect the most relevant features, permutation importance was analyzed. Classifier results using all features were: malignant lymphoma vs. non-lymphoma AUC = 0.86 (p < 0.01); HL vs. NHL AUC = 0.75 (p < 0.01); DLBCL vs. other NHL AUC = 0.65 (p < 0.01); MCL vs. FL AUC = 0.67 (p < 0.01). Classifying malignant lymphoma vs. non-lymphoma was also possible using only shape features AUC = 0.77 (p < 0.01), with the most important feature being sphericity. Based on only shape features, a significant AUC could be achieved for all tasks, however, best results were achieved combining shape and textural features. This study demonstrates the value of splenic imaging and radiomic analysis in the diagnostic process in malignant lymphoma detection and subtype classification.

Bilateral renal involvement in diffuse large B-cell lymphoma on fluorodeoxyglucose positron emission tomography/computed tomography

Secondary renal involvement in patients with diffuse large B-cell lymphoma (DLBCL) is rare and associated with poor prognosis. We, hereby, described a case of a patient diagnosed with DLBCL, in whom bilateral renal involvement was detected on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT). The patient received 4 courses of chemotherapy, and follow-up ¹⁸F-FDG PET/ CT revealed the complete resolution of the diffuse increased renal ¹⁸F-FDG uptake. Renal lymphoma is uncommon and ¹⁸F-FDG PET/CT is particularly useful for detecting extranodal involvement in DLBLC.

Multicentric primary diffuse large B-cell lymphoma in genitourinary tract detected on 18F-F-fluorodeoxyglucose positron emission tomography with computed tomography: An uncommon presentation of a common malignancy

Primary extranodal lymphomas (ENLs) are lymphomas with no or minor nodal involvement and a dominant extranodal component originating from any organ. Primary ENL originating in the genitourinary tract is extremely rare. Diffuse large B-cell lymphoma (DLBCL) is the most frequent histological subtype in primary genitourinary lymphoma. Lymphomatous involvement of genitourinary system organs is common in the setting of disseminated disease. Herein, we present a unique case of primary multicentric extranodal DLBCL of the urogenital system involving ureter, seminal vesicle, and penis detected on 18fluro-deoxyglucose positron emission tomography with computed tomography, and to the best of our knowledge, it is the first case report with multiorgan involvement within a single (urogenital) organ system in a patient without disseminated disease, i.e., with no other nodal or extranodal organ system involvement.

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)

An Uncommon Initial Presentation of T-Cell/Histiocyte-Rich B-Cell Lymphoma: Acute Renal Failure

T-cell/histiocyte-rich B-cell lymphoma accounts for approximately 1% to 3% of all cases of diffuse large B-cell lymphoma, and involvement of the kidneys comprises a mere 1% of the total primary extranodal lymphomas. We present a case of T-cell/histiocyte-rich B-cell lymphoma who had acute renal failure at initial presentation with bilateral lymphomatous infiltration depicted on FDG PET/CT scan. Four months after the treatment, a repeat FDG PET/CT scan revealed complete resolution of the renal lesions, indicative of the complete remission for kidneys.

CT and 18F- FDG-PET-CT Findings in Secondary Adrenal Lymphoma with Pathologic Correlation

RATIONALE AND OBJECTIVE

To evaluate computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) imaging manifestations of lymphomas secondarily involving the adrenal gland.

MATERIALS AND METHODS

Seven patients (Five men, two women; median age [range], 66 years [34-75 years]) with pathologically proven adrenal lymphoma were assessed retrospectively. Clinical findings, prior history of lymphoproliferative malignancy, CT (n = 7) and fludeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG-PET-CT) (n = 6) features were analyzed.

RESULTS

Six cases were diffuse large B-cell lymphoma, and one case was peripheral T-cell lymphoma. The longest diameter of the lesions ranged from 3.2 to 6.6 cm (median 4.3 cm). Six lesions were well-defined and one lesion was ill-defined. In five cases, an adreniform shape was preserved. No lesions contained fat, calcification or hemorrhage. Two lesions had necrosis on CT. Median (range) unenhanced CT density of six lesions was 31.8 (29.2-35.2) Hounsfield units. Following administration of IV contrast media (n = 6), three lesions enhanced homogenously whereas three enhanced heterogeneously. The median increase in attenuation was 35.1 Hounsfield units. Two patients had 15-minute delayed CT and they both demonstrated limited wash-out consistent with nonadenoma. Six patients had fludeoxyglucose positron emission tomography-computed tomography(^18-F-FDG-PET-CT) and all lesions were fludeoxyglucose (FDG) avid with a median SUV_max of 18.6 (range: 10.3-49.2).

CONCLUSION

Secondary adrenal lymphomas usually manifest as, large (>3 cm), well-defined, homogenously or slightly heterogeneously enhancing masses on CT with preserved adreniform shape. These lesions tend to show limited wash-out and high fludeoxyglucose (FDG) uptake.

Imaging features of extranodal involvement in paediatric Hodgkin lymphoma

Detecting extranodal disease in paediatric Hodgkin lymphoma is of great importance for both treatment and prognosis. Different imaging techniques can be used to identify these extranodal sites. This pictorial essay provides an overview of imaging features of extranodal disease manifestation in paediatric Hodgkin lymphoma.

18F-FDG PET/CT Findings of Non-Hodgkin Lymphoma Involving the Whole Genitourinary System

A sixty-two-year-old male patient underwent orchiectomy and was diagnosed with diffuse large B-cell lymphoma in the testicle and spermatic cord. ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) scanning was performed for initial staging. ¹⁸F-FDG PET/CT scan revealed multiple hyper-metabolic lymphadenopathies, lung lesions and mass lesions in the adrenal glands and kidneys. In addition, diffuse increased ¹⁸F-FDG uptake suggesting lymphomatous infiltration on the right testicle, prostate and left testicular veins were detected. The genitourinary system involvement is extremely rare in extra-nodal lymphomas and to the best of our knowledge this is the first case in the literature having ¹⁸F-FDG accumulating lesions in all genitourinary system structures.

Low rate of spleen involvement in sporadic Burkitt lymphoma at staging on PET-CT

BACKGROUND

Burkitt lymphoma is a highly aggressive B cell non-Hodgkin lymphoma. Cross-sectional imaging techniques that are used to detect liver and spleen involvement by lymphoma have high rates of false negative and false positive findings, and as such may reduce the accuracy of staging.

PURPOSE

This retrospective study evaluated the use of FDG PET-CT in determining splenic involvement at staging, in a relatively large cohort of adult patients with the sporadic form of Burkitt lymphoma (SBL).

PATIENTS AND METHODS

All adult patients who underwent FDG PET-CT for staging of SBL at one medical center during 2005-2014 were enrolled for this retrospective study.

RESULTS

Data were analyzed of 20 patients, with median age 49 years; 17 were male. PET-CT revealed highly intense FDG uptake, mean SUV max 11.4 ± 7.49 (range 4.3-38) in various tissues. None of the 20 patients had either focal or diffuse increased uptake of FDG in the spleen parenchyma. In 2 patients, there were highly FDG-avid soft tissue masses adjacent to the spleen, both in the context of direct peritoneal disease extension.

CONCLUSION

The spleen is rarely involved in SBL at the time of staging, according to PET-CT, except in cases with direct extension from adjacent peritoneal mass. The low rate of spleen involvement according to PET-CT may serve as a specific characteristic of SBL. Larger-scale clinical studies incorporating PET-CT scans in SBL are needed to confirm our observation.

Spectrum of CT Findings in Thoracic Extranodal Non-Hodgkin Lymphoma

Non-Hodgkin lymphoma (NHL) frequently manifests in extranodal structures in the chest, often in the form of secondary involvement but occasionally as primary disease. Because staging and treatment are affected by the presence of extranodal disease at imaging, radiologists' interpretation and management of suspicious findings are critical to patient care. Unfortunately, owing to considerable imaging overlap with other diseases, primary extranodal lymphoma is difficult to diagnose with imaging alone. Radiologists should have a heightened degree of suspicion in patients at risk (including patients with immune compromise, autoimmune diseases, or a history of stem cell or solid organ transplant) or with particular imaging appearances (including the vertebral wraparound sign, nonresolving consolidation, an infiltrative soft-tissue mass, and lesions demonstrating vascular encasement without invasion). For patients with known NHL, positron emission tomography/computed tomography (PET/CT) using fluorine 18 (¹⁸F)-labeled fluorodeoxyglucose (FDG) is now preferred for routine staging in most cases. CT remains heavily used, and identification of subtle extranodal involvement with CT can be improved with use of intravenous contrast material and careful review of multiplanar images. Pericardial effusion, pleural soft tissue (even when mild), mass-like consolidation, perilymphatic nodularity, and new lytic bone lesions are particularly suggestive of secondary involvement in a patient with known NHL. Magnetic resonance imaging is a helpful problem-solving tool when equivocal findings would change staging and treatment. This comprehensive review illustrates the spectrum of CT manifestations of extranodal NHL in the chest, including the pleura, lung, airways, heart, pericardium, esophagus, chest wall, and breast. ^©RSNA, 2017.

[Clinical features of 11 cases of primary bone lymphoma]

目的

探讨原发性骨淋巴瘤患者的临床特征、治疗及预后。

方法

回顾性分析11例原发性骨淋巴瘤患者的临床资料，对其临床特征，诊治过程及预后进行分析总结。

结果

11例患者中女7例，男4例，中位发病年龄45岁，仅1例患者以无痛性肿块起病，其余均以骨痛为首发症状，主要病理类型为弥漫大B细胞淋巴瘤和间变大细胞淋巴瘤。Ann Arbor临床分期ⅠE期3例，ⅡE期2例，ⅣE期6例。6例患者采取化疗联合放疗，2例行骨关节置换术联合化疗，3例选择单纯化疗。11例患者经初始治疗后5例达完全缓解，4例达部分缓解，2例疾病稳定。中位随访时间为21（6~58）个月，中位无进展生存期为17（5~58）个月。

结论

原发性骨淋巴瘤诊断时多为晚期，临床表现及影像学检查缺乏特异性，目前治疗主要采取以化疗为主的综合治疗，预后相对较好。

[A Case of Small Bowel Diffuse Large B-cell Lymphoma Mimicking Crohn's Disease]

A 66-year-old male with dyspepsia and weight loss was referred to our hospital for evaluation. On laboratory examination, anti-saccharomyces cerevisiae (ASCA)-IgA was positive and iron deficiency anemia was present. PET/CT and abdominal CT scan images showed multiple small bowel segmental wall thickening and inflammation. Capsule endoscopy images showed multiple small bowel ulcerative lesions with exudates. Based on laboratory test results and imaging studies, the patient was diagnosed with Crohn's disease and treated with prednisolone and 5-aminosalicylic acid (5-ASA). However, the patient underwent second operation due to small bowel perforation within 2 month after initiation of treatment. Pathology report of the resected specimen was compatible to primary small bowel diffuse large B cell lymphoma and pertinent treatment was given to the patient after recovery. Herein, we describe a case of primary small bowel diffuse large B cell lymphoma that was mistaken for Crohn's disease.

PET-CT for Evaluation of Spleen and Liver 18F-FDG Diffuse Uptake Without Lymph Node Enlargement in Lymphoma

The aim of the study was to compare differences between lymphoma and inflammation as indicated by high diffuse uptake of F-fluorodeoxyglucose (F-FDG) in the spleen, liver, and bone marrow without increased F-FDG uptake in the lymph nodes and without enlarged peripheral lymph nodes.Eighteen lymphoma patients and 14 inflammation patients were examined with F-FDG positron emission tomography-computer tomography (PET-CT). All patients displayed high diffuse uptake of F-FDG in the spleen, liver, and bone marrow without increased F-FDG uptake in the lymph nodes and without enlarged peripheral lymph nodes. Our analyses compared the maximum standardized uptake values (SUVmax) of F-FDG uptake ratios between the spleen/liver, the spleen/bone marrow, and the liver/bone marrow and further compared spleen sizes between lymphoma and inflammation patients.Using Student t test, no significant differences were found in the SUVmax ratios of spleen/liver and liver/bone marrow between the lymphoma and inflammation patients (t = 0.853, P = 0.401 > 0.05; t = 1.622, P = 0.115 > 0.05). However, the SUVmax ratio of the spleen/bone marrow of the lymphoma patients was significantly different from that of the inflammation patients (t = 2.426, P = 0.021 < 0.05). The spleen size between the lymphoma and inflammation patients was also significantly different (t = 2.911, P = 0.007 < 0.05).As indicated by F-FDG PET-CT, our study demonstrated that lymphoma and inflammation patients displayed a few differences despite both having high diffuse uptake of F-FDG in the spleen, liver, and bone marrow without enlarged peripheral lymph nodes and without increased F-FDG uptake in lymph nodes.

Diffuse Large B-Cell Lymphoma Presenting with Bilateral Renal Masses and Hematuria: A Case Report

Renal involvement is most often seen in conjunction with multisystemic, disseminated lymphoma either by direct extension from a retroperitoneal mass or via hematogenous spread. Primary lymphoma of the kidney is not a common entity and it is a controversial issue on account of the absence of lymphatic tissues in the normal kidney. In this case report, we describe a 19-year-old male with hematuria, acute kidney injury, and bilateral renal masses due to massive lymphomatous infiltration of the kidneys, which was diagnosed as diffuse large B-cell non-Hodgkin lymphoma by Tru-Cut biopsy.

Association between 18F-FDG PET/CT and MRI appearance of spinal leptomeningeal disease before and after treatment at a tertiary referral center

OBJECTIVE

Leptomeningeal disease (LMD), the presence of metastasis in the subarachnoid space, has devastating implications if left untreated. The gold standard for LMD diagnosis is cytologic analysis of cerebrospinal fluid (CSF); MRI is also used to evaluate suspected LMD. The purpose of this study was to compare the appearance of LMD in the spinal canal on 18F-FDG PET/CT imaging with the appearance of LMD on MRI and with CSF cytology.

METHODS

In twenty-one patients with cytologically-proven spinal LMD, findings on 18F-FDG PET/CT, MRI, and CSF cytology at diagnosis of LMD and after the initiation of treatment for LMD were retrospectively reviewed.

RESULTS

At diagnosis of LMD, abnormal 18F-FDG avidity was demonstrated in the spinal canal in six patients, and the anatomic distribution of 18F-FDG activity corresponded to the sites of LMD on MRI. All six of these patients were then treated with intrathecal chemotherapy. Follow-up 18F-FDG PET/CT and MRI were obtained in four of the six cases. In all four cases, normalization of 18F-FDG activity in the spinal canal and reduction of enhancement on MRI corresponded to the cytologic response to treatment, as determined by CSF analysis.

CONCLUSION

18F-FDG avidity in the spinal canal greater than the normal contents of the canal can suggest spinal LMD. This abnormal avidity may be detected before the diagnosis of LMD has been established with MRI or CSF cytology. The spinal canal should be routinely evaluated on 18F-FDG PET/CT in patients with suspected LMD so that appropriate treatment is initiated.

Current update on primary pancreatic lymphoma

OBJECTIVE

This article reviews the computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) CT findings of primary and secondary pancreatic lymphomas and discusses the role of endoscopic ultrasound-guided fine needle aspiration in diagnosis and management.

CONCLUSION

Pancreatic lymphoma has certain characteristic imaging features which may help distinguish it from the more common pancreatic adenocarcinoma. It is critical to make an accurate diagnosis, as the management of these two conditions is vastly different.

FDG PET-CT Finding in Bilateral Renal and Bone Involvement of Diffuse Large B-Cell Lymphoma

Thirty-six year old male patient with pathological fracture of the left tibia underwent intramedullary and soft tissue curettage. The histopathological examination revealed diffuse large B cell lymphoma. The patient underwent F18-FDG PET-CT scanning for initial staging. FDG PET-CT scan revealed hypermetabolic lesions at the left tibia and in bilateral kidneys. After the systemic chemotherapy and local radiotherapy to the tibia, repeated FDG PET/CT scan showed improvement of the previous hypermetabolic lesions, suggesting good response to therapy. Bone and renal involvement is an uncommon variant of diffuse large B-cell lymphoma and FDG PET-CT is an useful whole body imaging modality in these cases.

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.

Extranodal lymphoma originating in the gluteal muscle with adjacent bone involvement and mimicking a soft tissue sarcoma

Introduction

Extranodal lymphoma (ENL) in the muscles is a rare manifestation of non-Hodgkin lymphoma (NHL). The aim of this case report is to describe and evaluate the clinical presentation and important radiologic features of ENL affecting the musculoskeletal system.

Presentation of case

We present a 52-year-old female with a 3-week history of left gluteal pain. Computed tomography (CT) showed a non-uniformly early enhancing mass in the left gluteal muscle, the tumor demonstrating central necrosis and adjacent bone involvement. Fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT showed areas of increased ¹⁸F-FDG uptake in the left gluteal musculature, pelvic bones, para-aortic and mediastinal lymph nodes and both lungs. Histopathological examination showed a diffuse large B cell lymphoma (DLBCL). After 8 cycles of R-CHOP chemotherapy, the mass in the left gluteal muscle has completely disappeared

Discussion

Although destructive tumor originating in the gluteal muscle with adjacent bone involvement is more common in soft tissue sarcoma, lymphoma should be regularly included in the differential diagnosis. While CT is a useful modality for assessing soft tissue masses, disruption and injury of the surrounding tissues, PET/CT fusion is superior for the detection of unexpected extranodal sites of disease, or for exclusion of disease in the presence of nonspecific extranodal CT findings.

Conclusion

A rapid growth pattern and destructive masses that invade adjacent structures on CT are key findings of DLBCL, and ¹⁸F-FDG PET/CT is a useful imaging modality to accurately determine the disease stage and disease aggressiveness of NHL.

The incidence of secondary central nervous system involvement in patients with non-Hodgkin's lymphoma as detected by 18F-FDG PET/CT

AIM

Secondary central nervous system (CNS) involvement is a devastating and usually fatal complication of non-Hodgkin's lymphoma (NHL). We aimed to evaluate the incidence of secondary CNS involvement and the value of (18)F-FDG PET/computed tomography (CT) imaging in the detection of secondary CNS involvement in patients with NHL.

METHODS

A total of 123 immunocompetent patients (58 men, 65 women; mean age: 56.5±19.2) with biopsy-proven NHL who underwent (18)F-FDG PET/CT for primary staging (n=68) and restaging (n=55) of recurrent disease were reviewed retrospectively. Those with secondary CNS involvement as diagnosed on PET/CT were identified. CNS involvement was confirmed by MRI and cerebrospinal fluid cytology.

RESULTS

The clinical Ann Arbor stages of the patient population were as follows: stage I - 10 patients; stage II - 44 patients; stage III - 32 patients, and stage IV - 37 patients. PET/CT detected CNS involvement in six patients. The ages of patients with CNS disease ranged from 23 to 68 (mean: 47.2) years. Three patients presented with CNS involvement associated with systemic disease manifestation at initial diagnosis; one patient had isolated CNS relapse and two had relapsed systemic NHL with progression to CNS involvement. Relapse interval was 8-12 months following initial diagnosis. The types of CNS involvement in patients were as follows: parenchymal (n=2), leptomeningeal (n=2), both parenchymal and leptomeningeal (n=1), and pituitary gland involvement (n=1), which is an uncommon manifestation. Median duration of survival was 2.5 months after the diagnosis of CNS involvement.

CONCLUSION

The incidence of secondary CNS involvement was 4.4% at initial diagnosis and 5.4% among patients with relapse of lymphoma in our study. PET/CT is a sensitive, objective, and valuable method for the diagnosis of secondary CNS involvement in patients with NHL. In addition, pituitary gland involvement, as a very rare manifestation of secondary CNS lymphoma, has been shown.

131I-tositumomab myeloablative radioimmunotherapy for non-Hodgkin's lymphoma: radiation dose to the testes

PURPOSE

To investigate radiation doses to the testes delivered by a radiolabeled anti-CD20 antibody and its effects on male sex hormone levels.

MATERIALS AND METHODS

Testicular uptake and retention of (131)I-tositumomab were measured, and testicular absorbed doses were calculated for 67 male patients (54 ± 11 years of age) with non-Hodgkin's lymphoma who had undergone myeloablative radioimmunotherapy (RIT) using (131)I-tositumomab. Time-activity curves for the major organs, testes, and whole body were generated from planar imaging studies. In a subset of patients, male sex hormones were measured before and 1 year after the therapy.

RESULTS

The absorbed dose to the testes showed considerable variability (range = 4.4-70.2 Gy). Pretherapy levels of total testosterone were below the lower limit of the reference range, and post-therapy evaluation demonstrated further reduction [4.6 ± 1.8 nmol/l (pre-RIT) vs. 3.8 ± 2.9 nmol/l (post-RIT), P<0.05]. Patients receiving higher radiation doses to the testes (≥ 25 Gy) showed a greater reduction [4.7 ± 1.6 nmol/l (pre-RIT) vs. 3.3 ± 2.7 nmol/l (post-RIT), P<0.05] compared with patients receiving lower doses (<25 Gy), who showed no significant change in total testosterone levels.

CONCLUSION

The testicular radiation absorbed dose varied highly among individual patients. Patients receiving higher doses to the testes were more likely to show post-RIT suppression of testosterone levels.

Thyroid nodule as a first manifestation of Hodgkin lymphoma-report of two cases and literature review

Lymphomas account for less than 5% of thyroid malignant lesions. Vast majority of them are B-cell non-Hodgkin lymphomas (NHL), while Hodgkin lymphoma (HL) is extremely rare. Here we present two cases of HL, at baseline manifesting as a thyroid lesion. First patient, 29-year-old pregnant female, initially suspected for metastatic medullary thyroid cancer, was eventually diagnosed with mixed cellularity type of thyroid HL. Second patient, 22-year-old woman with suspicion of advanced thyroid cancer, was in the end diagnosed with an extra-lymphatic classical HL of the thyroid. In both cases, despite repeated fine-needle aspiration biopsy, cytological examination gave inconclusive or misleading results. On histopathological examination, thyroid tumor cells were positive for CD15 and CD30 antigen, which is typical for Reed-Sternberg cells. In the report authors also discuss difficulties in management as well as potential importance of novel methods such as FISH, PCR and other molecular techniques in diagnostics of thyroid lymphomas.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2896947559559648.

Fusion PET-CT detection of neurolymphomatosis originating from primary breast lymphoma: A case report and literature review

Neurolymphomatosis (NL) is an extremely rare manifestation. Involvement of the cranial and peripheral nerves is an unusual manifestation of NL which is occasionally difficult to diagnose using conventional imaging modalities. A 45-year-old female in complete remission from primary breast lymphoma presented with multiple neurological symptoms. (18)F-FDG PET/CT revealed multiple nodular hypermetabolic lesions along the cranial and peripheral nerves, which corresponded to the patient's neurological symptoms. These findings suggest that (18)F-FDG PET/CT successfully detects the infiltration of cranial and peripheral nerves by lymphoma.

Extensive Extranodal Involvement of Rare Sites in Non Hodgkin's Lymphoma Detected on (18)F- FDG PET-CT: A Case Report

We present a case of a 23 year-old male treated for Hodgkin's lymphoma who developed diffuse large B-cell lymphoma (DLBCL) 8 years after achieving remission. (18)F-fluorodeoxyglucose positron emission tomography computed tomography ((18)F-FDG PET-CT) was done, which revealed extensive extranodal involvement of bilateral atria, bilateral kidneys, ileo-caecal junction and left testis along with mesenteric and retroperitoneal lymph nodal involvement. Renal and cardiac lesions were not detected by contrast-enhanced CT. Simultaneous lymphomatous involvement of rare sites such as heart, kidneys and testis in a single patient has not been reported before.

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.

Cross-sectional evaluation of thoracic lymphoma

Thoracic lymphomas most frequently involve mediastinal lymph nodes in the anterior mediastinum and paratracheal areas. The lymphomas may also involve lung, thymus, pleura, pericardium, chest wall, and the breast and their radiologic manifestations are diverse. Lymphomas (mostly BALT lymphoma and large B-cell lymphoma) may arise primarily from the lung with various imaging features including single or multiple nodule(s) and area(s) of consolidation. CT is currently the most important imaging modality for the evaluation of thoracic lymphoma but FDG PET also plays a crucial role in the clinical management of these cases.

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.

Splenic hamartoma in a child in the era of PET-CT

We present a case of a healthy 7-year-old female with an incidental finding of a growing splenic lesion, diagnosed as a splenic hamartoma after splenectomy. This case highlights the diagnostic challenge of splenic lesions and that the role of positron emission tomography/computerized tomography (PET/CT) in defining splenic lesions in the pediatric population remains to be defined.

Nodal status of malignant lymphoma in pelvic and retroperitoneal lymphatic pathways: PET/CT

Nodal involvement of abdominal lymphatic pathways occurs in a number of histologic subtypes of malignant lymphoma. The histologic diagnosis of abnormal uptake in abdominal lymphatic pathways includes mainly non-Hodgkin lymphoma with B-cell lineage and Hodgkin lymphoma. Initial involvement of pelvic and retroperitoneal lymphatic pathways can result from a variety of underlying non-Hodgkin's lymphoma: follicular lymphoma, diffuse large B-cell lymphoma, marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type, and mantle cell lymphoma. The diagnosis of these clinical entities requires various imaging techniques, including fluorine-18-fluorodeoxyglucose ((18)FDG) positron emission tomography/computed tomography (PET/CT), computed tomography, (67)Gallium scintigraphy, and magnetic resonance imaging (MRI). Specific symptoms of these diseases are often lacking, but intense (18)FDG accumulation on PET/CT may be a marker of disease activity. Interpretation of the presence of and the specific pattern of (18)FDG uptake may obviate the need for invasive biopsy. However, distinction of abnormal uptake is often difficult to determine because focal accumulation of (18)FDG in the urinary tract or intestine mimics nodal involvement in the pelvic and retroperitoneal lymphatic pathways. In this review, specific conditions causing nodal involvement of pelvic and retroperitoneal lymphatic pathways in patients with malignant lymphoma that may impact diagnostic and treatment decisions are highlighted.

CT and 18F-FDG PET for noninvasive detection of splenic involvement in patients with malignant lymphoma

OBJECTIVE

The purpose of this study was to determine the sensitivity and specificity of (18)F-FDG PET, CT, and combined PET/CT in the detection of splenic involvement at initial staging of lymphoma.

MATERIALS AND METHODS

A retrospective longitudinal analysis was performed on the records of 111 patients with proven lymphoma who had undergone PET and CT before and after treatment. CT scans were evaluated independently by two radiologists, and PET scans by two nuclear medicine physicians. Abnormal CT findings were defined as low-attenuation nodules or a splenic index greater than 725 cm(3) (> 2 SDs above the mean in 100 controls). An abnormal PET finding was defined as splenic uptake greater than hepatic uptake. True splenic involvement was defined retrospectively on the basis of the treatment response assessed with criteria revised in the International Harmonization Project on lymphoma. Observer agreement and sensitivity and specificity values were calculated.

RESULTS

Observer agreement for CT splenic index and PET findings was good. For initial splenic staging, the sensitivity and specificity of CT, PET, and PET/CT were 91% and 96%, 75% and 99%, and 100% and 95%.

CONCLUSION

For initial staging of splenic involvement in malignant lymphoma, the sensitivity and specificity of PET/CT can reach 100% and 95%. The sensitivity of the combined approach is higher than that of either technique alone.

Cross-sectional evaluation of thoracic lymphoma

In patients who have lymphoma, the presence and distribution of thoracic involvement is important in both tumor staging and treatment. Thoracic involvement in Hodgkin lymphoma (HL) is more common than in non-Hodgkin lymphoma (NHL). In HL, mediastinal lymphadenopathy with contiguous spread is a hallmark, and lung parenchymal involvement at the initial presentation is almost always associated with mediastinal lymphadenopathy. NHL is more heterogeneous and generally presents at a more advanced stage than HL. Most often, mediastinal involvement occurs as a disseminated or recurrent form of extrathoracic lymphoma. Bulky mediastinal disease with compression of adjacent structures can occur, particularly with high-grade subtypes of NHL and isolated lung disease without mediastinal lymphadenopathy can occur in contrast to HL.

Recurrence of primary breast lymphoma in contralateral breast: case report and review of the literature

Lymphoma presenting as a breast mass is rare, although well documented. Although recurrence rates can reach approximately 50%, recurrence in the contralateral breast is rare. We report a case of recurrent primary breast lymphoma (PBL), which was discovered on screening mammography after a 5-year disease-free interval from initial diagnosis.