Castleman Disease of the Thorax: Clinical, Radiologic, and Pathologic Correlation: From the Radiologic Pathology Archives

Imaging of Castleman Disease

Castleman disease (CD) is a group of rare and complex lymphoproliferative disorders that can manifest in two general forms: unicentric CD (UCD) and multicentric CD (MCD). These two forms differ in clinical manifestation, imaging appearances, treatment options, and prognosis. UCD typically manifests as a solitary enlarging mass that is discovered incidentally or after development of compression-type symptoms. MCD usually manifests acutely with systemic symptoms including fever and weight loss. As a whole, CD involves lymph nodes throughout the chest, neck, abdomen, pelvis, and axilla and can have a wide variety of imaging appearances. Most commonly, lymph nodes or masses in UCD occur in the chest, classically with well-defined borders, hyperenhancement, and possible characteristic patterns of calcification and/or feeding vessels. Lymph nodes affected by MCD, while also hyperenhancing, tend to involve multiple nodal chains and manifest alongside anasarca or hepatosplenomegaly. The polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) subtype of MCD may demonstrate lytic or sclerotic osseous lesions in addition to features typical of MCD. Since a diagnosis of CD based solely on imaging findings is often not possible, pathologic confirmation with core needle biopsy and/or surgical excision is necessary. Nevertheless, imaging plays a crucial role in supporting the diagnosis of CD, guiding appropriate regions for biopsy, and excluding other potential causes or mimics of disease. CT is frequently the initial imaging technique used in evaluating potential CD. MRI and PET play important roles in thoroughly evaluating the disease and determining its extent, especially the MCD form. Complete surgical excision is typically curative for UCD. MCD usually requires systemic therapy. ^©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Multicentric Castleman disease of hyaline‑vascular variant with paraneoplastic pemphigus results in abnormal lung function: Report of 3 cases

Castleman disease (CD) is clinically divided into unicentric CD (UCD) and multicentric CD (MCD). Hyaline-vascular variant (HV) is the most common pathological type of UCD, while the plasma cell type (PC) is the most common type of MCD and thus, hyaline-vascular variant multicentric CD (HV-MCD) is a rare type of CD. In addition, its etiology has remained elusive. The present study retrospectively analyzed the medical records of 3 patients diagnosed as HV-MCD admitted to The First Affiliated Hospital of Guangxi Medical University (Guangxi, China) between January 2007 and September 2020. A total of 2 males and 1 female were admitted. The areas involved varied considerably. Respiratory symptoms were seen in 3 cases, along with fever, weight loss and splenomegaly. Damage to the skin and mucous membranes resulted in oral ulcers when accompanied by paraneoplastic pemphigus (PNP). Dry and wet rales were found in all patients. All 3 cases were complicated with PNP and had hypoxemia and obstructive ventilation dysfunction. In accordance with PC-MCD, it manifested as lymph node enlargement and may involve several lymph nodes. Computed tomography mainly indicated bronchiectasis and mediastinal lymph node enlargement. In 1 case, chemotherapy failed after local mass excision, 1 case remitted after chemotherapy but the lung lesion was irreversible and 1 case was untreated and soon died of respiratory failure. The cases of HV-MCD with pulmonary involvement were induced by small airway lesions and associated with poor prognosis. Respiratory symptoms along with systemic symptoms were common.

Unmet Clinical Needs in the Management of Idiopathic Multicentric Castleman Disease: A Consensus-based Position Paper From an ad hoc Expert Panel

Castleman disease describes a group of heterogeneous clinicopathological disorders now included in the tumor-like lesions with B-cell predominance of the World Health Organization classification. Managing idiopathic multicentric Castleman disease (iMCD) is challenging, because few systematic studies or comparative randomized clinical trials have been conducted. International, consensus evidence-based guidelines for iMCD were published in 2018, but gaps in the therapeutic options for difficult-to-treat patients, who do not respond to siltuximab and other conventional therapies, still exist. This article presents the results of group discussion among an ad hoc constituted Panel of Italian experts to identify and address unmet clinical needs (UCNs) in managing iMCD. Recommendations on the appropriateness of clinical decisions and proposals for new research concerning the identified UCNs were issued through formalized multiple-step procedures after a comprehensive analysis of the scientific literature. The following key UCNs were addressed: strengthening the diagnostic certainty in iMCD patients before planning first-line therapy; management of siltuximab therapy; choice and management of immune-modulating, or chemotherapy agents in patients resistant/intolerant to siltuximab therapy. While most of the conclusions reached by the Panel are consistent with the existing guidelines, some alternative therapeutic options were stressed, and the discussion contributed to bringing forth the issues that need further investigation. Hopefully, this comprehensive overview will improve the practice of iMCD and inform the design and implementation of new studies in the field.

18F-FDG PET/CT and contrast-enhanced CT in the diagnosis of Castleman disease

OBJECTIVE

Castleman disease (CD) is a rare group of lymphoproliferative disorders, which is easily confused with lymphoma or other solid tumors. Hence, this study aimed to investigate the diagnostic role of ¹⁸F-FDG PET/CT and contrast-enhanced CT (CECT) in patients with CD.

METHODS

Clinicopathological characteristics, and ¹⁸F-FDG PET/CT and CECT findings and parameters were retrospectively reviewed in 32 patients with CD.

RESULTS

These 32 patients (12 males, 20 females; median age, 41 years) consisted of 17 unicentric CD (UCD) patients and 15 multicentric CD (MCD) patients. Compared with MCD, UCD had a higher prevalence in female (82.4% vs. 40.0%) and hyaline vascular subtype (94.1% vs. 40.0%) (P < 0.05). FDG uptake was avid in all cases, including moderate uptake in 7 cases and intense uptake in 25 cases. The median SUVmax, SUVmean, MLV, and TLG of all cases were 4.4 (range, 1.4-23.6), 2.7 (range, 1.1-15.2), 26.6 (range, 4.8-393.0), and 78.8 (range, 9.4-1545.6), respectively. The lesions of 29 cases showed homogeneous enhancement, and marked enhancement was observed in 27 cases. ¹⁸F-FDG PET/CT corrected 6.3% CECT diagnoses, while CECT corrected 37.5% PET/CT diagnosis. The accuracy of combined PET/CT and CECT was superior to PET/CT or CECT alone (78.1%, 31.3%, and 62.5%). Besides, higher SUVmax and SUVmean were found in male subjects, MCD, and plasma cell subtype (P < 0.05), while higher MLV and TLG were observed in larger lesion size and volume (P < 0.05).

CONCLUSION

Castleman disease most commonly appears as marked and homogeneous enhancement meanwhile with moderate or intense FDG uptake. ¹⁸F-FDG PET/CT combined with CECT was the effectively diagnostic modality for CD. The glucose metabolism of CD was associated with gender, clinical classification, histopathological classification, and lesion size and volume.

Autoimmune disease of head and neck, imaging, and clinical review

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

Idiopathic Multicentric Castleman Disease with Cutaneous Manifestation: Case Report

Castleman disease constitutes a rare class of lymphoproliferative disorders, with an estimated incidence of 21 to 25 per million patient years. The idiopathic subtype exhibits a significantly diverse clinical presentation, which can imitate many autoimmune, malignant, and infectious diseases. Cutaneous manifestations are uncommon and require in-depth investigation, especially when concurrent lymphadenopathy is present. A 79-year-old female, with a chronic, complicated erysipelas-like lesion, presented with bilaterally enlarged inguinal lymph nodes; after surgical excision, their histopathological examination revealed Castleman disease. Even though it is a benign condition, patients are often predisposed to developing certain types of malignancies, which can deteriorate their prognosis. An accurate and early diagnosis, along with effective treatment and prevention of recurrence, is of utmost importance in order to increase the patients’ overall survival and quality of life.

Pediatric mediastinal masses

Mediastinal masses are categorized based on the International Thymic Malignancy Interest Group (ITMIG) classification into prevascular, visceral and paravertebral compartments. The schema is based on cross-sectional imaging, mainly CT, and helps with generating a differential diagnosis based on location of the mass. Up to half of all pediatric mediastinal tumors are malignant. In this review we describe mediastinal masses that are relevant to the pediatric population, as well as the role of MR imaging of mediastinal masses and its advantages.

Solitary extramedullary plasmacytoma in the lung misdiagnosed as lung cancer: A case report and literature review

Background

Extramedullary plasmacytoma (EMP) is an extremely rare kind of soft tissue plasma cell neoplasm without bone marrow involvement or other systemic characteristics of multiple myeloma. Primary pulmonary plasmacytoma (PPP), with no specific clinical manifestations, is an exceedingly rare type of EMP. Because of its complexity, PPP is often difficult to diagnose. Computed tomography-guided percutaneous core needle biopsy (CT-guided PCNB) has been shown to have high sensitivity, specificity and accuracy for characterization of pulmonary lesion, particularly if malignancy is suspected. Here we presented a rare case of PPP diagnosed with CT-guided PCNB.

Case presentation

A 78-year-old female smoker who visited our outpatient clinic for a mass in the left lower lobe of the lung. Pathological based on CT-guided PCNB yielded a PPP with no lymph node or other distant metastasis.

Conclusions

Extramedullary plasmacytoma should be considered in the differential diagnosis of a pulmonary mass.

Nonmalignant Thoracic Disorders: An Appraisal of Fluorodeoxyglucose and Non-fluorodeoxyglucose PET/Computed Tomography Applications

PET/computed tomography (CT) with fluorodeoxyglucose and nonfluorodeoxyglucose PET tracers has established itself in the management of malignant disorders. Its role in the assessment of nonmalignant conditions, such as infectious and noninfectious inflammatory diseases and other benign conditions, has emerged independently and alongside its role being evaluated in malignancy and continues to evolve. It is evident that PET/CT has the potential to play a significant role in various nonmalignant disorders of the thorax. This review highlights current developments and areas where PET/CT has a potential to impact the clinical management of nonmalignant thoracic conditions with special focus on nonfluorodeoxyglucose tracers.

Pearls and pitfalls in imaging of mediastinal masses

In imaging of the mediastinum, advances in computed tomography (CT), and magnetic resonance imaging (MRI) technology enable improved characterization of mediastinal masses. Knowledge of the boundaries of the mediastinal compartments is key to accurate localization. Awareness of distinguishing imaging characteristics allows radiologists to suggest a specific diagnosis or narrow the differential. In certain situations, MRI adds value to further characterize mediastinal lesions.

Human Oncoviruses and Thoracic Tumors: Understanding the Imaging Findings

Approximately 1.4 million virus-induced cancers occur annually, representing roughly 10% of the cancer burden worldwide. Seven oncogenic DNA and RNA viruses (ie, oncoviruses) are implicated in approximately 12%-25% of all human cancers owing to a variety of mechanisms as uncommon consequences of the normal viral life cycle. These seven well-recognized human oncoviruses are Epstein-Barr virus (EBV), human T-lymphotropic virus 1, hepatitis B virus, hepatitis C virus, HIV, human papilloma virus (HPV), and human herpesvirus 8 (HHV-8). Several viruses-namely, EBV, HPV, and Kaposi sarcoma herpesvirus or HHV-8-are increasingly being recognized as being related to HIV and/or AIDS, the growing number of transplant cases, and the use of immunosuppressive therapies. Infectious and inflammatory processes, and the accompanying lymphadenopathy, are great mimickers of human oncovirus-related tumors. Although it is often difficult to differentiate these entities, the associated clinical setting and radiologic findings may provide clues for an accurate diagnosis and appropriate management. Malignant lymphoid lesions are best evaluated with multidetector chest CT. The radiologic findings of these lesions are often nonspecific and are best interpreted in correlation with clinical data and histopathologic findings. ^©RSNA, 2022.

Unicentric castleman disease located in the left popliteal fossa: a case report

Background

Castleman disease (CD) is a lymphoproliferative disease of unknown etiology, it can affect any lymph nodes of the body but rarely affects the popliteal fossa.

Case presentation

We present a 67-year-old woman with touching solitary painless mass in the left popliteal fossa for one week. Imaging showed multiple soft-tissue masses of different sizes in the left popliteal muscle space, the T1 weighted image showed hypointense to isointense, the fat-suppressed T2 weighted images showed subtle hypersignal intermingled with linear of hypointense,and displayed homogeneous contrast enhancement after administration of gadolinium. Complete surgical resection was performed. Pathologically demonstrated plasma cell type CD.

Conclusion

We described a rare case plasma cell type of UCD located in the popliteal fossa which might help to enrich the clinical spectrum of this rare site and unique subtype of UCD. This case illustrates that CD should be considered in the differential diagnosis of every hypervascularity soft tissue tumor in any anatomic location, especially when they occur in the region of lymph node distribution.

Radiology of Castleman disease: the pivotal role of imaging in diagnosis, staging, and response assessment of this rare entity

Castleman Disease (CD) is a rare entity that typically presents as an enhancing nodal mass in the mediastinum or head and neck region on computed tomography (CT). It may manifest as unicentric or multicentric regions of lymph node enlargement. A key clinical issue in the context of CD is delayed diagnosis, which contributes adversely to patient outcome, given that accurate diagnosis facilitates earlier treatment of this curable disease. This article will address relevant imaging aspects, with reference to typical and atypical imaging features of CD, illustrated using examples from our specialist centre; the imaging journey for patients with CD; and will provide practical pointers to radiologists in differentiating CD from other benign and malignant causes of enhancing lymphadenopathy, including lymphoma and neoplastic adenopathy. We will also review current classification tools and staging challenges with reference to World Health Organization guidelines, International Working Group guidelines as well as the Lugano classification. Finally, we will discuss the potential role of additional imaging techniques in CD, highlighting novel imaging methods and expanded utilities from our specialist centre.

Role of Imaging in a Case of Toxoplasmosis Presenting as Generalized Lymphadenopathy

Toxoplasmosis is caused by Toxoplasma gondii an obligate protozoan intracellular parasite. The disease has variable prevalence globally and is usually asymptomatic. Pregnant and immunocompromised people are at risk of getting infected. Enlarged lymph nodes are the most frequently observed clinical form of Toxoplasma in humans, mostly affecting posterior cervical nodes. Other organs usually affected are the brain and eyes. We present a case of toxoplasmosis with generalized lymphadenopathy mimicking metastasis in a lady with a previous history of operated pancreatic neoplasm.

Unicentric Castleman disease: multidetector computed tomography classification with surgical and pathologic correlation

Background

This study aimed to correlate multidetector computed tomography (MDCT) classification of unicentric Castleman disease with the surgical and pathologic features.

Methods

The imaging manifestations of 63 cases of unicentric Castleman disease confirmed by pathology were retrospectively analyzed. Every patient underwent an MDCT examination. Classification based on imaging manifestations, surgical, histopathological, and imaging features were simultaneously reviewed and analyzed by two radiologists, with any disagreements resolved by consensus.

Results

Sixty-three patients with unicentric Castleman disease were divided into I-IV types by imaging manifestations: type I, single mass with smooth margin (n=5); type II, single mass with irregular or lobulated margin (n=33); type III, single invasive mass with blurred margin (n=20); and type IV, multiple fused masses (n=5). Thirty-eight cases of type I and type II were diagnosed as hyaline-vascular type by pathology after complete surgical resection; 20 cases were type III, in which eight cases were partially resected, 17 cases were pathologically diagnosed as hyaline-vascular type, and the remaining three cases were a mixed type. In five cases of type IV that could not be completely resected, four cases were hyaline-vascular type, and one case was plasma cell type.

Conclusions

MDCT is an excellent tool for the detection and diagnosis of unicentric Castleman disease. Classification by MDCT features is a reliable method for evaluating tumor infiltration and growth mode, which helps surgical optimization.

18F-FDG PET/CT imaging features of patients with multicentric Castleman disease

OBJECTIVE

The aim of this study is to investigate the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the evaluation of multicentric Castleman disease (MCD).

METHODS

Thirty-five patients with pathologically confirmed MCD who underwent 18F-FDG PET/CT were retrospectively included. The FDG uptake and CT findings of lymph nodes, pulmonary involvement, spleen, and bone marrow were assessed and the maximum standardized uptake value (SUVmax) of each lesion was measured. The locations of lymph nodes were also evaluated.

RESULTS

18F-FDG PET/CT showed increased uptake in multiple nodal regions in 34 out of 35 MCD patients. The most frequently involved nodal sites were the cervical, iliac, axillary, and inguinal areas, and the least common was paraaortic and abdominal nodes. The involved lymph nodes were not confluent and presented a relatively symmetric pattern on PET/CT images. The highest SUVmax of lymph nodes per patient ranged from 2 to 19 with a mean value of 5.61 ± 3.12. Pulmonary manifestation including cysts, nodules, and interstitial lung disease were found in 10 patients, eight of whom demonstrated mild to moderate uptake in the lungs. 18F-FDG PET/CT also revealed other findings including hypermetabolic spleen (n = 8) and bone marrow (n = 23), elevated uptake in salivary glands (n = 8). Four patients also underwent follow-up PET/CT scans after therapy, and three of them displayed decreased metabolism.

CONCLUSION

18F-FDG PET/CT is a useful tool in the diagnosis, evaluation, and follow-up of MCD by providing systemic manifestations of lymphadenopathy, pulmonary involvement, and hypermetabolic spleen or bone marrow. Furthermore, the lymphadenopathy in MCD presented a predominantly peripheral distribution, relatively symmetric, moderately hypermetabolic, and not confluent pattern on 18F-FDG PET/CT.

Complete Resolution of a Case of TAFRO Syndrome Accompanied by Mediastinal Panniculitis, Adrenal Lesion, and Liver Damage with Hyperbilirubinemia

TAFRO syndrome is a systemic inflammatory, lymphoproliferative disorder, but the pathophysiology of the disease is unknown. It is typically characterized by thrombocytopenia, anasarca, a fever, reticulin fibrosis, renal dysfunction, and organomegaly. However, other manifestations have been also reported. We encountered a 43-year-old man with TAFRO syndrome who showed mediastinal panniculitis, liver damage, and adrenal lesions in addition to the core signs. He achieved complete remission with combination therapy of corticosteroids, tocilizumab, and cyclosporin, and remission was maintained even after drug discontinuation at 15 months. Atypical manifestations and complete remission of TAFRO syndrome were remarkable features of our case.

Emerging role of 18F-FDG PET/CT in Castleman disease: a review

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging.

Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT02817997

Spectrum of [18F]FDG-PET/CT Findings in Benign Lymph Node Pathology

Diffuse lymphadenopathy has a long differential diagnosis that includes both malignant and benign causes. As part of the lymphadenopathy work-up, many patients undergo [¹⁸F]FDG-PET/CT for purposes of ruling out malignancy. FDG-avid lymph nodes, however, are not specific for malignancy. This review will illustrate the spectrum of nodal findings on FDG-PET/CT with correlation to other cross-sectional imaging and clinical history in patients with representative infectious, inflammatory, and benign lymphoproliferative disorders. These findings are important for the nuclear medicine radiologist to understand, as they can represent common pitfalls in the work-up of lymphadenopathy. While FDG-PET/CT may be limited in ascertaining a definitive diagnosis in a disease process as the cause of lymphadenopathy, it can help to narrow this differential and rule out certain diseases in the correct clinical context.

Imaging of the Middle and Visceral Mediastinum

The visceral mediastinum contains important vascular and non-vascular structures including the heart, great vessels, lymph nodes, and portions of the esophagus and trachea. Multiple imaging modalities, including chest radiography, computed tomography, MR imaging, and nuclear medicine studies, can be used to detect, diagnose, and characterize masses in this compartment. Lymphadenopathy is the most common process involving the visceral mediastinum and can be seen with a wide variety of diseases. Less commonly seen entities include foregut duplication cysts, neoplasms and other lesions arising from the trachea and esophagus, paragangliomas as well as other mesenchymal tumors.

HIV Lymphadenopathy: Differential Diagnosis and Important Imaging Features

OBJECTIVE. The purpose of this article is to review important imaging and clinical features to help elucidate causes of lymphadenopathy in patients with HIV infection. CONCLUSION. HIV lymphadenopathy has various causes generally categorized as inflammatory or reactive, such as immune reconstitution syndrome; infectious, such as tuberculous and nontuberculous mycobacterial infections and HIV infection itself; and neoplastic, such as lymphoma, Kaposi sarcoma, and Castleman disease. It is important to consider patients' demographic characteristics, clinical presentations, CD4 lymphocyte counts, and radiologic features to identify likely causes of lymphadenopathy.

Analysis of Clinical Characteristics, Pathological Changes and Changes of Interleukin-6 (IL-6) and C-Reactive Protein (CRP) in Children with Castleman's Disease

Background

The aim of this study was to analyze the pathological changes, clinical characteristics and changes in immunity, interleukin-6 (IL-6) and C-reactive protein (CRP) in children with Castleman’s disease (CD).

Material/Methods

A total of 15 CD child patients were enrolled as observation group, while 20 normal children receiving healthy examination were enrolled as healthy control group. The pathological changes, clinical characteristics and changes in immunity and serum IL-6 and CRP expressions were retrospectively analyzed in observation group.

Results

The clinical manifestation of unicentric CD (UCD) was mainly enlargement of cervical lymph nodes without liver-spleen enlargement and fever, and the major pathological type was the hyaline-vascular type. Multicentric CD (MCD) child patients all had anemia, fever and other systemic symptoms, and the major pathological type was the plasma-cell type. There were expressions of the immune indexes, including cluster of differentiation 3 (CD3), CD4, CD8, CD20, and CD79, in a certain degree, while CD138 and VS38C expressions displayed the polyclonal proliferation of plasma cells, rather than neoplastic proliferation. The Epstein-Barr virus and human herpes virus-8 detection results were negative, and CD21 in follicular dendritic cells in abnormal germinal center was positive. The expression levels of serum IL-6 and CRP in observation group were higher than those in control group (P<0.05).

Conclusions

There are immune dysfunction and increased expressions of serum IL-6 and CRP in child patients with CD, so it can be speculated that the immune abnormality and overexpression of serum inflammatory factors may be associated with the occurrence of CD.

The value of multiparameter 18F-FDG PET/CT imaging in differentiating retroperitoneal paragangliomas from unicentric Castleman disease

The aim of this study was to investigate the value of multiple parameters retrieved from the FDG PET/CT studies, including SUVmax, SUVmean, SUVpeak, MTV, TLG, tumour size in differentiating retroperitoneal paragangliomas from UCD. 28 patients with solitary retroperitoneal masses who had undergone preoperative ¹⁸F-FDG PET/CT were retrospectively evaluated. Histopathology by surgical resection confirmed 17 paragangliomas and 11 UCDs. SUVmax, SUVmean, SUVpeak, MTV, TLG, and tumour size of ¹⁸F-FDG PET/CT were measured for each patient. Mann–Whitney U-test was used to assess differences in multiple parameters between paragangliomas and UCDs. The ROC curve analysis was performed to determine the differential diagnostic value of these parameters. Paragangliomas presented significantly higher SUVmax (P < 0.001), SUVmean (P = 0.001), SUVpeak (P < 0.001), and TLG (P = 0.024) than UCDs, whereas no significant difference was observed in MTV. The AUCs for differentiating paragangliomas and UCDs were 0.920, 0.888, 0.909, and 0.765 for SUVmax, SUVmean, SUVpeak, and TLG, respectively. The SUVmax cut-off of 7.75 yielded 82.4% sensitivity and 100% specificity for predicting paragangliomas. This study indicated that ¹⁸F FDG PET/CT-derived multiple metabolic parameters are useful in distinguishing between paragangliomas and UCDs. SUVmax showed the best result for the differential diagnosis of these two diseases among multiple metabolic parameters.

Mimickers of pulmonary lymphoma

There are multiple entities that involve the lung that have radiographic, clinical, and morphologic overlaps with pulmonary lymphoma. In this review, we will discuss these entities in detail and provide relevant updates.

Different Imaging Features of Retroperitoneal Unicentric Castleman's Disease: A Case Report

Castleman's disease is a rare disease which is difficult to diagnose early due to its lack of specific manifestations, and also is easily confused with lymphoma or other solid tumors. Castleman's disease can occur in any part of the body containing lymph nodes and is most common in the chest, followed by the neck, abdomen, and axillae. A 37-year-old woman was admitted to our hospital because of a tumor near the adrenal gland found by computed tomography. Positron emission tomography-computed tomography revealed that the retroperitoneal tumor may be a malignant disease. However, the pathological diagnosis after laparoscopic resection was retroperitoneal Castleman's disease, hyaline vascular type.

Castleman disease in the hepatic-gastric space: A case report

BACKGROUND

Castleman disease, also known as giant lymph node hyperplasia, was first reported in 1956. It is a rare benign proliferative pathological change of the lymph nodes.

CASE SUMMARY

The patient, a 33-year-old woman, had epigastric distension for half a year. Examinations were performed in a local hospital. Computed tomography scan showed round soft tissue nodules, about 5.45 cm in diameter, in the hepatic-gastric space. Endoscopic ultrasound and endoscopic ultrasound guided fine needle aspiration was performed on the patient. Rapid on-site evaluation, hematoxylin eosin staining and histopathology of the puncture smear was performed. According to the Diff-Quik staining and hematoxylin eosin staining results of preoperative endoscopic ultrasound guided fine needle aspiration puncture smears as well as the immunohistochemistry results, Castleman disease was highly suspected. A sufficient preoperative evaluation was made, and a precise surgical plan was developed. Postoperative pathology confirmed Castleman disease.

CONCLUSION

Endoscopic ultrasound guided fine needle aspiration can extract internal tissues of the tumor for histological and cytological examinations and provide accurate diagnosis as much as possible. Therefore, a sufficient preoperative evaluation can be made, and a precise surgical plan can be developed.

Imaging and clinical features of Castleman Disease

BACKGROUND

Castleman disease (CD) is a group of uncommon lymphoproliferative disorders that is easily confused with lymphoma or other solid tumors. The purpose of our study was to evaluate the imaging and clinical findings of CD, and thus improve the understanding and diagnosis of CD.

METHODS

This retrospective study included 74 patients (37 men and 37 women, mean age ± standard deviation, 35 ± 15.2 years,) with histopathologically confirmed CD diagnosed based on CT or MRI between January 2010 and May 2017. The CT and MRI findings were analyzed by two radiologists in consensus, and clinical presentation and histopathologic characteristics were documented.

RESULTS

The CD subtypes included 61 hyaline vascular variant cases (82.4%) and 13 plasma cell variant cases (17.6%). Unicentric CD and multicentric CD were observed in 65 (87.8%) and 9 (12.2%) patients, respectively. On non-enhanced CT, enlarged nodes with hypodensity or isodensity were seen, whereas varying degrees of enhancement were observed in contrast-enhanced CT. Homogeneous and heterogeneous enhancements were observed in 43 (62.3%) and 26 (37.7%) patients, respectively. Hypertrophied vessels and calcification were detected in 38 (51.2%) and 18 (24.3%) patients, respectively. MRI revealed hypointense to isointense lesions on T1-weighted images, isointense to hyperintense lesions on T2-weighted images, and hyperintense lesions on diffusion-weighted imaging; 9 (75%) and 3 (25%) patients demonstrated homogeneous and heterogeneous enhancement, respectively.

CONCLUSION

CD often shows well-defined, mildly hypodense or isodense, homogeneous lymph nodules on non-enhanced CT/MRI, with intermediate and marked enhancement on contrast-enhanced CT/MRI. Calcification and hypertrophied vessels may be valuable diagnostic features.

Castleman disease versus lymphoma in neck lymph nodes: a comparative study using contrast-enhanced CT

BACKGROUND

The purpose of this study was to determine the contrast-enhanced CT characteristics for differentiating between Castleman disease (CD) and lymphoma in neck lymph nodes.

METHODS

This retrospective study evaluated the number (solitary or multiple), strength of contrast-enhancement, type of contrast-enhancement, surrounding vessels, contrast-enhanced Hounsfield unit (HU) values, and anatomical distributions of lymph nodes in 34 patients with confirmed CD and 55 patients with newly diagnosed untreated lymphoma. Independent t-tests, receiver operating characteristic (ROC) curve analysis, and chi-square tests were used to evaluate the variables and CT features.

RESULTS

Several significant differences were found between CD and lymphoma. The interval between first contrast-enhanced CT and biopsy/surgery was significantly longer in the CD group (mean 72 ± 105 days, median 60 days) than in the lymphoma patients (mean 30 ± 2 days, median 12 days; p = 0.015). The lymphoma patients presented significantly more often with fatigue and fever (p = 0.023 and p = 0.016 respectively) than did the CD subjects. HU values of nodules after enhancement were significantly higher in the CD patients than in the lymphoma patients. In cases involving multiple lymph nodes, in all the CD cases, all affected nodes were located in only the left or right side of the neck, not bilaterally. ROC analysis showed a significant difference in contrast-enhanced CT attenuation values between lymphoma and CD (p < 0.001, area under the curve = 0.954), with a cut-off value of 92.5 HU. We constructed a decision tree according to these imaging characteristics.

CONCLUSIONS

Contrast-enhanced CT can be useful for differentiating between CD and lymphoma.

Role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scan in Castleman's Disease

Castleman's disease (CD) is a rare benign lymphoproliferative disorder. We are presenting three cases of CD of which one is unicentric CD, and the other two are an idiopathic multicentric CD. One of the two multicentric cases is associated with POEMS syndrome. The whole body ¹⁸F-Fluorodeoxyglucose positron-emission tomography–computed tomography scan plays a significant role in identifying the centricity, distribution of disease, response to therapy, and in early detection of remission.

Castleman's disease presenting as a pleural tumor: a case report with CT findings

Castleman's disease (CD) is an uncommon benign lymphoproliferative disorder which most commonly involves the mediastinum but rarely affects the pleura. We report a case of unicentric CD that presents as a pleural mass in a 45-year-old man, which was subsequently resected followed by an unexpected diagnosis on histologic examination. Although rare, CD should be included in the differential diagnosis of well-enhancing pleural mass.

Castleman disease in the hilum liver mimicking the lymph node metastasis of hepatocellular carcinoma on 18F-FDG PET/CT: A case report

RATIONALE

Castleman disease is a rare lymphoproliferative disorder which etiology is unknown. It is divided into 2 subtypes: the plasma cell variant and the hyaline vascular variant. The most common site is the hilum of the lungs and mediastinum. Castleman disease is often ignored by clinicians because of not frequently encountering in clinical and the lower uptake of F-FDG. Here, we report a case of hepatocellular carcinoma accompanied by Castleman disease in the hilum of the liver, which was misdiagnosed as the lymph node metastasis in F-FDG PET/CT imaging.

PATIENT CONCERNS

A 63-year-old male with chief complaint of acratia and poor appetite for 2 weeks.

DIAGNOSES

Hepatocellular carcinoma accompanied by Castleman disease in the hilum of liver.

INTERVENTIONS

Right hemihepatectomy and hilar lymph node dissection was performed and preventative transcatheter arterial chemoembolization therapy was given after the surgery.

OUTCOMES

The case had multiple systemic metastasis due to tumor progression.

LESSONS

Castleman disease is a benign and rare lympholiferative disease, and easy to be ignored in clinical. The case of hepatic carcinoma with Castleman disease in the hilum of liver has never been reported before. Here, we report it and hope it provides a differential diagnosis for clinicians in the following similar cases.

International, evidence-based consensus diagnostic criteria for HHV-8-negative/idiopathic multicentric Castleman disease

Human herpesvirus-8 (HHV-8)-negative, idiopathic multicentric Castleman disease (iMCD) is a rare and life-threatening disorder involving systemic inflammatory symptoms, polyclonal lymphoproliferation, cytopenias, and multiple organ system dysfunction caused by a cytokine storm often including interleukin-6. iMCD accounts for one third to one half of all cases of MCD and can occur in individuals of any age. Accurate diagnosis is challenging, because no standard diagnostic criteria or diagnostic biomarkers currently exist, and there is significant overlap with malignant, autoimmune, and infectious disorders. An international working group comprising 34 pediatric and adult pathology and clinical experts in iMCD and related disorders from 8 countries, including 2 physicians that are also iMCD patients, was convened to establish iMCD diagnostic criteria. The working group reviewed data from 244 cases, met twice, and refined criteria over 15 months (June 2015 to September 2016). The proposed consensus criteria require both Major Criteria (characteristic lymph node histopathology and multicentric lymphadenopathy), at least 2 of 11 Minor Criteria with at least 1 laboratory abnormality, and exclusion of infectious, malignant, and autoimmune disorders that can mimic iMCD. Characteristic histopathologic features may include a constellation of regressed or hyperplastic germinal centers, follicular dendritic cell prominence, hypervascularization, and polytypic plasmacytosis. Laboratory and clinical Minor Criteria include elevated C-reactive protein or erythrocyte sedimentation rate, anemia, thrombocytopenia or thrombocytosis, hypoalbuminemia, renal dysfunction or proteinuria, polyclonal hypergammaglobulinemia, constitutional symptoms, hepatosplenomegaly, effusions or edema, eruptive cherry hemangiomatosis or violaceous papules, and lymphocytic interstitial pneumonitis. iMCD consensus diagnostic criteria will facilitate consistent diagnosis, appropriate treatment, and collaborative research.