Imaging of abdominal lymphoma

Left ovarian mass revealing multivisceral lymphoma

Lymphoma encompasses a range of cancers originating in the lymphatic system, categorized into Hodgkin lymphoma and non-Hodgkin lymphoma. Hodgkin lymphoma classically present as nodal disease, whereas non-Hodgkin lymphoma tends to involve extranodal regions. While it can be part of a systemic lymphoma, isolated nodal involvement is not uncommon. Extranodal lymphoma can affect virtually any organ or tissue, with the spleen, liver, gastrointestinal tract, pancreas, abdominal wall, genitourinary tract, adrenal glands, peritoneal cavity, and biliary tract being among the most commonly involved sites, in decreasing order of frequency. We present a case involving a 54-year-old woman presented with left iliac fossa pain. A sonography was performed, which showed left pelvic mass, magnetic resonance imaging showed left ovarian mass with enlargement of the cervix. Computed tomography revealed enlargement of the pancreas and adrenal glands, along with masses in the kidneys associated with extensive pathological lymph node enlargement in the para-aortic and pelvic regions. The patient underwent biopsy of a para-aortic lymph node, which revealed a diffuse large B cell lymphoma.

Unusual Signal of Lymphadenopathy in Children with Nodular Sclerosing Hodgkin Lymphoma

PURPOSE

The current guidelines for initial cross-sectional imaging in pediatric lymphomas involve computed tomography (CT) of the chest, abdomen, and pelvis. However, whole-body magnetic resonance imaging (MRI) can be favored over CT for diagnosing and staging the disease, given its lack of ionizing radiation and its higher tissue contrast. Imaging characteristics of lymphoid tissue on MRI include a high T2/short tau inversion recovery (STIR) signal. A low or intermediate signal of lymphadenopathy on T2 and STIR images is an unexpected finding, noted anecdotally in nodular sclerosing Hodgkin lymphoma. This signal may be characteristic of a histological subtype of the disease and, if confirmed, could potentially be used to avoid biopsy. In this study, we aimed to review signal characteristics of lymphadenopathy in patients with biopsy-confirmed nodular sclerosing Hodgkin lymphoma.

METHODS

We undertook a retrospective review of relevant MR studies of patients with nodular sclerosing Hodgkin lymphoma. Studies were reviewed by an experienced pediatric radiologist regarding lymph node signal, especially on T2/STIR.

RESULTS

Eleven children with nodular sclerosing Hodgkin lymphoma were included. Median age at the time of MRI was 14.3 (IQR: 13.9-16.1) years, and nine were boys. Five patients showed some lymphadenopathy with a low T2/STIR signal, and six showed an intermediate T2/STIR signal. Central gadolinium non-enhancement was observed in four patients.

CONCLUSIONS

All eleven patients (100%) with a diagnosis of nodular sclerosing Hodgkin lymphoma showed some lymphadenopathy with a low or intermediate T2/STIR signal, and five children (45.5%) showed a frank low signal of some lymphadenopathy, a feature which may prove to be a biomarker for this histology.

Gα13 restricts nutrient driven proliferation in mucosal germinal centers

Germinal centers (GCs) that form in mucosal sites are exposed to gut-derived factors that have the potential to influence homeostasis independent of antigen receptor-driven selective processes. The G-protein Gα13 confines B cells to the GC and limits the development of GC-derived lymphoma. We discovered that Gα13-deficiency fuels the GC reaction via increased mTORC1 signaling and Myc protein expression specifically in the mesenteric lymph node (mLN). The competitive advantage of Gα13-deficient GC B cells (GCBs) in mLN was not dependent on T cell help or gut microbiota. Instead, Gα13-deficient GCBs were selectively dependent on dietary nutrients likely due to greater access to gut lymphatics. Specifically, we found that diet-derived glutamine supported proliferation and Myc expression in Gα13-deficient GCBs in the mLN. Thus, GC confinement limits the effects of dietary glutamine on GC dynamics in mucosal tissues. Gα13 pathway mutations coopt these processes to promote the gut tropism of aggressive lymphoma.

Typical and Atypical Imaging Features of Malignant Lymphoma in the Abdomen and Mimicking Diseases

Malignant lymphoma typically presents with homogeneous enhancement of enlarged lymph nodes without internal necrotic or cystic changes on multiphasic CT, which can be suspected without invasive diagnostic methods. However, some subtypes of malignant lymphoma show atypical imaging features, which makes diagnosis challenging for radiologists. Moreover, there are several lymphoma-mimicking diseases in current clinical practice, including leukemia, viral infections in immunocompromised patients, and primary or metastatic cancer. The ability of diagnostic processes to distinguish malignant lymphoma from mimicking diseases is necessary to establish effective management strategies for initial radiological examinations. Therefore, this study aimed to discuss the typical and atypical imaging features of malignant lymphoma as well as mimicking diseases and discuss important diagnostic clues that can help narrow down the differential diagnosis.

Renal Lymphoma Mimicking a Retroperitoneal Hematoma

We report the case of a 65-year-old female with an atypical presentation of renal lymphoma at computed tomography (CT), which was initially misinterpreted as a retroperitoneal hematoma. This case highlights the importance to keep a high level of suspicion in order to make a prompt diagnosis since treatment strategies differ significantly.

Hitting a Moving Target: Successful Management of Diffuse Large B-cell Lymphoma Involving the Mesentery With Volumetric Image-guided Intensity Modulated Radiation Therapy

INTRODUCTION

We report successful treatment of mesenteric diffuse large B-cell lymphoma (DLBCL) using localized involved site radiation therapy (ISRT), intensity modulated radiation therapy (IMRT), and daily computed tomography (CT)-image guidance.

PATIENTS AND METHODS

Patients with mesenteric DLBCL treated with RT between 2011 and 2017 were reviewed. Clinical and treatment characteristics were analyzed for an association with local control, progression-free survival (PFS), and overall survival.

RESULTS

Twenty-three patients were eligible. At diagnosis, the median age was 52 years (range, 38-76 years), and 57% (n = 13) had stage I/II DLBCL. All patients received frontline chemotherapy (ChT) (R-CHOP [rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone], n = 19; dose-adjusted R-EPOCH [rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin], n = 4) with median 6 cycles. Prior to RT, salvage ChT for refractory DLBCL was given to 43% (n = 10) and autologous stem cell transplantation was administered in 13% (n = 3). At the time of RT, positron emission tomography-CT revealed 5-point scale of 1 to 3 (48%; n = 11), 4 (9%; n = 2), and 5 (44%; n = 10). All patients received IMRT, daily CT imaging, and ISRT. The median RT dose was 40 Gy (range, 16.2-49.4 Gy). Relapse or progression occurred in 22% (n = 5). At a median follow-up of 37 months, the 3-year local control, PFS, and overall survival rates were 80%, 75%, and 96%, respectively. Among patients treated with RT after complete metabolic response to frontline ChT (n = 8), the 3-year PFS was 100%, compared with 61% for patients with a history of chemorefractory DLBCL (n = 15; P = .055). Four of the 5 relapses occurred in patients with 5-point scale of 5 prior to RT (P = .127).

CONCLUSION

Mesenteric involvement of DLBCL can be successfully targeted with localized ISRT fields using IMRT and daily CT-image guidance.

Abdominal manifestations of extranodal lymphoma: pictorial essay

In the appropriate clinical setting, certain aspects of extranodal abdominal lymphoma, as revealed by current cross-sectional imaging techniques, should be considered potentially diagnostic and can hasten the diagnosis. In addition, diagnostic imaging in the context of biopsy-proven lymphoma can accurately stage the disease for its appropriate treatment. The purpose of this article was to illustrate the various imaging aspects of extranodal lymphoma in the abdomen.

Diffuse Large B-Cell Lymphoma in the Era of Precision Oncology: How Imaging Is Helpful

Diffuse large B cell lymphoma (DLBCL) is the most common histological subtype of Non-Hodgkin's lymphoma. As treatments continues to evolve, so do imaging strategies, and positron emission tomography (PET) has emerged as the most important imaging tool to guide oncologists in the diagnosis, staging, response assessment, relapse/recurrence detection,and therapeutic decision making of DLBCL. Other imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, and conventional radiography are also used in the evaluation of lymphoma. MRI is useful for nervous system and musculoskeletal system involvement and is emerging as a radiation free alternative to PET/CT. This article provides a comprehensive review of both the functional and morphological imaging modalities, available in the management of DLBCL.

Ovarian cancer mimics: how to avoid being fooled by extraovarian pelvic masses

In our clinical experience, pelvic masses from a variety of anatomic sites may be misdiagnosed as ovarian cancer. This tendency to overdiagnose a rare disease probably reflects both its protean imaging appearance and concern for its potential morbidity and mortality. However, radiologists can better serve patients with an analytic approach to the anatomic and tissue features of pelvic masses. We review a range of ovarian cancer mimics and illustrate the radiologic reasoning enabling correct diagnosis.

De-misty-fying the mesentery: an algorithmic approach to neoplastic and non-neoplastic mesenteric abnormalities

Mesenteric abnormalities are often incidentally discovered on cross-sectional imaging performed during daily clinical practice. Findings can range from the vague "misty mesentery" to solid masses, and the possible etiologic causes encompass a wide spectrum of underlying pathologies including infectious, inflammatory, and neoplastic processes. Unfortunately, the clinical and imaging findings are often non-specific and may overlap. This article discusses the various diseases that result in mesenteric abnormalities. It provides a framework to non-invasively differentiate these entities, when possible.

Imaging Features of Various Adrenal Neoplastic Lesions on Radiologic and Nuclear Medicine Imaging

OBJECTIVE

The purpose of this review is to describe the features of diverse adrenal neoplastic lesions on radiologic and nuclear medicine imaging.

CONCLUSION

Various neoplastic lesions with or without malignant potential can occur in the adrenal gland. Knowledge of imaging features of adrenal lesions on radiologic and nuclear medicine imaging will facilitate differential diagnosis and assessment of malignant potential.

Imaging for Staging and Response Assessment in Lymphoma

Lymphoma comprises a heterogeneous group of diseases; remarkable advances have been made in diagnosis and treatment. Diagnostic imaging provides important information for staging and response assessment in patients with lymphoma. Over the years, staging systems have been refined, and dedicated criteria have been developed for evaluating response to therapy with both computed tomography (CT) and fluorine-18 fluorodeoxyglucose positron emission tomography (PET)/CT. The most recent system proposed for staging and response assessment, known as the Lugano classification, applies to both Hodgkin and non-Hodgkin lymphoma. The use of standardized criteria for staging and response assessment is important for making accurate treatment decisions and for determining the direction of further research. This review provides an overview of the updated CT and PET response criteria to familiarize the radiologist with the most important and clinically relevant aspects of lymphoma imaging. It also provides a short clinical update on lymphoma and the associated spectrum of imaging findings.

From the radiologic pathology archives: Adrenal tumors and tumor-like conditions in the adult: radiologic-pathologic correlation

Advanced imaging often reveals adrenal tumors and tumor-like conditions in both symptomatic and asymptomatic patients. When adrenal disease is clinically suspected, cross-sectional imaging can be helpful in evaluating the etiology of the patient's symptoms. When adrenal disease is incidentally identified, what the clinician and patient really want to know is whether the findings are benign or malignant, as this ultimately will affect their next step in management. Using radiologic-pathologic correlation, we broadly classify common, uncommon, and rare tumors and tumor-like conditions that can occur in the adrenal as benign or malignant. This classification follows predominant trends in observed biologic behavior while acknowledging those tumors that may behave in the minority in an unpredictable manner. We review the clinical background and presentation of functional adrenal tumors including Conn syndrome, Cushing syndrome, and catecholamine-secreting tumors, as well as their relationship with adrenal anatomy. We discuss a variety of benign tumors, including adrenal cortical adenoma (including oncocytoma) and pheochromocytoma, as well as uncommonly and rarely encountered tumors such as myelolipoma, hemangioma, lymphangioma, schwannoma, ganglioneuroma, and adenomatoid tumor. A variety of tumefactive but nonneoplastic lesions are addressed, including adrenal cortical hyperplasia, adrenal hemorrhage, adrenal cysts, and infections. Malignant tumors discussed include adrenal cortical carcinoma, the rare malignant pheochromocytoma, lymphoma, metastases, and sarcomas. For each tumor and tumor-like lesion, the clinical presentation, epidemiology, key imaging findings, diagnostic differential considerations, and management options are briefly addressed. Finally, an approach to the workup of suspected or incidentally discovered tumors is presented based on a selected literature survey and our clinical experience. Radiologists play an important role in identification and diagnosis of adrenal tumors and tumor-like conditions in both symptomatic and asymptomatic patients.

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

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

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

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

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

Imaging of primary gastrointestinal lymphoma

Primary gastrointestinal (GI) lymphoma most often arises from stomach, small bowel, or colon. The 2 most common subtypes of primary GI lymphoma include low-grade mucosa-associated lymphoid tissue lymphoma, strongly associated with Helicobacter pylori infection, and high-grade diffuse, large B-cell lymphoma. Primary GI lymphoma demonstrates a myriad of imaging manifestations that can commonly mimic other pathologies. Timely and accurate diagnosis remains important because treatment and prognosis of primary GI lymphoma differ significantly from other GI malignancies and even lymphoma of other primary sites.

Practical approach to MRI of female pelvic masses

OBJECTIVE

Female pelvic masses have a broad differential diagnosis, including benign and malignant neoplasms and nonneoplastic entities.

CONCLUSION

By using a systematic approach to the evaluation of a complex pelvic mass, including incorporating the clinical and surgical history, and by using multiparametric MRI to identify the anatomic origin, morphologic features, and tissue composition of a mass, a short meaningful differential diagnosis or definitive diagnosis can often be established.

Mesenteric tumors: diagnosis and treatment

Mesenteric tumors are rare and consist of a heterogeneous group of lesions. Masses may arise from any of the mesenteric components: peritoneum, lymphatic tissue, fat, and connective tissue. Cellular proliferation can also arise from infectious or inflammatory processes. They can be classified as solid or cystic, benign or malignant. Mesenteric tumors are usually discovered incidentally or during investigation of non-specific symptoms. While clinical examination and imagery may suffice to make the diagnosis, histopathology is often required by either needle percutaneous or surgical biopsy, or immediate excision. Therapeutic management options vary widely depending on the nature of the lesion; they range from simple observation or medical therapy to surgery. Benign well-delineated mesenteric masses that are symptomatic can often be treated by simple enucleation. But invasive malignant tumors require a carcinologic resection; a careful preoperative evaluation to assess the relationship between the mass and adjacent vascular and digestive structures is essential since they may dictate the need for extensive sacrifice of bowel with resultant intestinal insufficiency due to short bowel syndrome.

Abundant macroscopic fat in intra-abdominal lymph nodes involved in the course of a patient with chronic lymphocytic leukaemia: presentation of imaging findings with biopsy correlation

The presence of a small amount of macroscopic fat is not unusual in the hilar region of normal lymph nodes. However, abundant replacement of the lymph node with fat is highly unusual and may appear as metastatic lymph node disease in the course of fat-predominant liposarcomas or in the case of coeliac disease complicated by cavitating lymph node syndrome. In this case report, a patient with chronic lymphocytic leukaemia/small lymphocytic lymphoma who demonstrated an increasing abundance of macroscopic fat in the diseased lymph nodes is presented. To the best of our knowledge, the imaging findings of abundant fat in lymph nodes in the course of lymphoma have not been reported before. The presence of macroscopic fat may be seen in the presence of actively involved lymph nodes in the presence of chronic lymphocytic leukaemia.

Intratumoral heterogeneity of F-18 FDG uptake differentiates between gastrointestinal stromal tumors and abdominal malignant lymphomas on PET/CT

OBJECTIVE

Gastrointestinal stromal tumors (GISTs) and malignant lymphomas (MLs) in the abdomen are often observed as tumors of unknown origin on F-18 FDG PET/CT. The purpose of this study was to evaluate the intratumoral metabolic heterogeneity of F-18 FDG uptake on PET to determine if it might be helpful to discriminate between these tumors.

METHODS

The F-18 FDG PET/CT findings of 21 large abdominal tumors were retrospectively evaluated (9 GISTs and 12 MLs). Intratumoral heterogeneity was evaluated by visual scoring (visual score: 0, homogeneous; 1, slightly heterogeneous; 2, moderately heterogeneous; 3, highly heterogeneous) and by the cumulative standardized uptake value (SUV) histograms on transaxial PET images at the maximal cross-sectional tumor diameter. Percent tumor areas above a threshold from 0 to 100% of the maximum SUV were plotted and the area under curve of the cumulative SUV histograms (AUC-CSH) was used as a heterogeneity index, where lower values corresponded with increased heterogeneity. Correlation between the visual score and the AUC-CSH was investigated by the Spearman's rank test.

RESULTS

GISTs exhibited heterogeneous uptake of F-18 FDG, whereas MLs showed rather homogeneous uptake on visual analysis (visual score: 2.67 ± 0.50 and 0.58 ± 0.79, respectively; p < 0.001). The AUC-CSH was significantly lower for the GISTs than for the MLs (0.41 ± 0.14 and 0.64 ± 0.08, respectively; p < 0.001). Significant correlations were observed between the visual score and the AUC-CSH (ρ = -0.866, p < 0.001).

CONCLUSION

GISTs exhibited significantly heterogeneous intratumoral tracer uptake as compared with the MLs. Evaluation of the intratumoral heterogeneity of F-18 FDG uptake may help in the discrimination between these tumors.

Clinicopathological features and treatment of primary small intestinal lymphoma: recent advances

Primary small intestinal lymphoma (PSIL) is an extra-nodal lymphoma whose clinical and histological presentations are usually heterogeneous depending on the site of the lesion. Proper staging criteria are important for clinicopathological diagnosis. Although there is no consensus regarding the role of surgery and chemotherapy in the treatment of PSIL, surgery followed by chemotherapy and radiotherapy is still the main treatment. This review summarizes the clinicopathological features, diagnosis, therapy and prognosis of PSIL.

Extranodal lymphoma from head to toe: part 2, the trunk and extremities

OBJECTIVE

Lymphoma can affect virtually every tissue in the body, producing a variety of imaging appearances. In this article, the extranodal manifestations of this disease in the trunk and extremities are illustrated and the imaging features that aid in the diagnosis are reviewed.

CONCLUSION

Knowledge of the imaging appearances of extranodal lymphoma can aid the differential diagnosis of mass lesions encountered in tissues throughout the body on different imaging modalities.

Diffuse large B cell lymphoma of the mesentery: an unusual presentation and review of the literature

INTRODUCTION

Diffuse large B cell lymphoma is the most commonly diagnosed non-Hodgkin's lymphoma, whereas lymphoma is the most common cause of mesenteric masses. We herein present a very rare case of a young male patient with a giant diffuse large B cell lymphoma of the mesentery that was incidentally diagnosed during his admission for a road traffic accident.

MATERIALS AND METHODS

At laparotomy, a huge tumor measuring 18 x 14 x 10 cm was found originating from the jejunal mesentery. Despite the giant size of the tumor, the patient was completely asymptomatic. After complete surgical recection with clear margins, he recieved six cycles of CHOP chemotherapy in the pre-rituximab era.

RESULTS AND DISCUSSION

He remained disease-free 2 years after surgery, but unfortunately, he relapsed with disseminated disease and died 6 months later. Mesenteric lymphomas may remain asymptomatic until they reach a large size. The presence of a bulky mesenteric mass is a poor prognostic indicator.

CONCLUSION

Although chemotherapy is the treatment of choice for diffuse large B cell lymphoma, in some cases radical surgery has a role in establishing a definitive diagnosis.