Increased FDG Uptake Research Articles

"Mini Brain" Appearance in Spinal Metastasis From Type A Thymoma Detected by 18F-FDG PET/CT.

A 66-year-old man presented with persistent dull pain in the lower back for over 7 months. An expansile lytic lesion in the L4 vertebral body showed a characteristic "mini brain" appearance on MRI, which is highly suggestive of plasmacytoma. 18F-FDG PET/CT scan revealed increased FDG uptake in the L4 lesion, with an additional finding of a mass in the anterior mediastinum that showed mild FDG uptake. Lumbar surgery and complete resection of the anterior mediastinum tumor confirmed spinal metastatic type A thymoma, which was classified as p-T1aN0M1b, stage IVb. The patient's condition improved postsurgery and chemotherapy, with long-term follow-up necessary due to recurrence risk.

18F-FDG PET/CT Findings of Isolated Renal Metastasis From Squamous Cell Lung Cancer.

We present the 18F-FDG PET/CT findings of a 64-year-old man with isolated renal metastasis. He had a history of radical surgery for squamous cell lung cancer 14 months ago, followed by chemotherapy and immunotherapy. The renal metastasis presented as a small focus of increased FDG uptake in the restaging 18F-FDG PET/CT scan, which was regarded as renal cortical tracer retention. The renal metastasis was more prominent on the second PET/CT performed 5 months later. The patient subsequently underwent radical nephrectomy, and histopathological examination confirmed the diagnosis of renal squamous cell carcinoma metastasis.

Multifocal Hemorrhagic Choriocarcinoma With Diffuse Pancreatic FDG Uptake on 18F-FDG PET/CT.

Choriocarcinoma is a rare and highly malignant trophoblastic tumor. We present a case involving a 30-year-old woman with abdominal pain, hemoptysis, and elevated serum amylase levels. Initial clinical suspicion included acute pancreatitis. Noncontrast and contrast-enhanced CT revealed hemorrhagic and hypervascular lesions in the lungs, pancreas, liver, and kidneys. 18F-FDG PET/CT showed diffuse pancreatic enlargement with increased FDG uptake (SUVmax, 5.3), consistent with malignancy. Histopathology confirmed choriocarcinoma with elevated HCG levels. Following chemotherapy, HCG levels declined, indicating a positive therapeutic response. 18F-FDG PET/CT effectively detected choriocarcinoma and assessed its systemic involvement.

Diffusely Increased FDG Uptake of the Kidney Caused by Severe Renal Artery Stenosis.

Renal artery stenosis can result in renovascular hypertension and ischemic nephropathy. We describe FDG PET/CT and delayed abdominal FDG PET/MRI findings in a kidney associated with severe renal artery stenosis resulting from renal artery invasion in retroperitoneal alveolar echinococcosis. The renal parenchyma showed diffusely increased activity on both FDG PET/CT and delayed FDG PET/MRI. There was no activity in the renal collecting system on FDG PET/CT and focal urine activity in the renal calyces on delayed FDG PET/MRI. This case indicates that renal artery stenosis should be included in the differential diagnosis of diffuse renal parenchymal FDG uptake.

FDG-PET/CT Avid Uptake of a Biopsy-Proven Aggressive Melanotic Schwannoma of the S2 Spinal Nerve Root

Abstract Background Malignant melanotic nerve sheath tumors (MMNSTs), also known as a melanocytic schwannoma (MS), are a rare type of peripheral nerve sheath tumors including Schwann cells with melanocytic differentiation. Only a few cases of spinal MMNST have been reported in literature. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) could be used to detect these lesions. Case Description A 70-year-old man with a 6-month history of backache was admitted to our hospital. PET/CT showed a paravertebral soft tissue mass along the spinal nerve at the S2 level with strong FDG uptake, and a nodule with increased FDG uptake in the right lobe of the left liver. A CT-guided biopsy of the S2 lesion was performed. The final diagnosis was spinal MS with hepatic metastasis. The patient received stereotactic body radiation therapy. Conclusion Herein, we report the PET/CT findings of a case of MS with hepatic metastasis. FDG-PET/CT is helpful in the differential diagnosis of benign and malignant lesions although nonspecific.

Application of Dynamic [18F]FDG PET/CT Multiparametric Imaging Leads to an Improved Differentiation of Benign and Malignant Lung Lesions.

To evaluate the potential of whole-body dynamic (WBD) 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography ([18F]FDG PET/CT) multiparametric imaging in the differential diagnosis between benign and malignant lung lesions. We retrospectively analyzed WBD PET/CT scans from patients with lung lesions performed between April 2020 and March 2023. Multiparametric images including standardized uptake value (SUV), metabolic rate (MRFDG) and distribution volume (DVFDG) were visually interpreted and compared. We adopted SUVmax, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) for semi-quantitative analysis, MRmax and DVmax values for quantitative analysis. We also collected the patients' clinical characteristics. The variables above with P-value < 0.05 in the univariate analysis were entered into a multivariate logistic regression. The statistically significant metrics were plotted on receiver-operating characteristic (ROC) curves. A total of 60 patients were included for data evaluation. We found that most malignant lesions showed high uptake on MRFDG and SUV images, and low or absent uptake on DVFDG images, while benign lesions showed low uptake on MRFDG images and high uptake on DVFDG images. Most malignant lesions showed a characteristic pattern of gradually increasing FDG uptake, whereas benign lesions presented an initial rise with rapid fall, then kept stable at a low level. The AUC values of MRmax and SUVmax are 0.874 (95% CI: 0.763-0.946) and 0.792 (95% CI: 0.667-0.886), respectively. DeLong's test showed the difference between the areas is statistically significant (P < 0.001). Our study demonstrated that dynamic [18F]FDG PET/CT imaging based on the Patlak analysis was a more accurate method of distinguishing malignancies from benign lesions than conventional static PET/CT scans.

605. MITOCHONDRIAL METABOLISM IN UPPER GI ADENOCARCINOMA DETERMINES PATIENT SURVIVAL

Abstract Background Mitochondrial oxidative phosphorylation (OXPHOS) is responsible for meeting the vast majority of cellular energy demands. Ever since the description of aerobic glycolysis by Warburg in 1927, it has been recognised that cancers have dysfunctional metabolism. Clinically, this Warburg effect is the basis of FDG-PET imaging, increased FDG uptake represents increased tumour glycolysis and translates to worse upper GI adenocarcinoma outcomes. The cause of OXPHOS disruption in upper GI adenocarcinoma is poorly understood, its impact on potential therapeutic strategies is yet to be explored. This is particularly pertinent in upper GI adenocarcinomas as despite recent improvements, 5-year survival remains alarmingly low. Method Oesophageal and gastric adenocarcinoma samples collected in the UK from 175 patients (89 oesophageal adenocarcinoma, 86 gastric adenocarcinoma, 131 male, 44 female, median age=65, IQR=12) who underwent radical resection with curative intent between 1995 and 2009. Quantitative immunofluorescence were used to determine expressions of OXPHOS Complex I and IV at a single cell level. Patients were divided into high vs. low expressors of Complex I and IV using K-means clustering to allow for subsequent subgroup analysis. Result Survival analysis demonstrated significantly worse outcomes for low expressors as compared to high expressors of Complex I at 5 years post-op (5-year survival probability low expressors=0.440, 95%CI=0.358-0.539, high expressors=0.629, 95%CI=0.515-0.769, P-value=0.048). Similarly comparison of Complex IV expression also demonstrates disadvantageous survival for Complex IV low expressors (5-year survival probability low expressors=0.432, 95%CI=0.346-0.538, high expressors=0.603, 95%CI=0.499-0.729, P-value=0.042). The low expressors of Complex I and IV encompassed significantly more Stage III disease as per AJCC 7th edition. The low vs. high expression Complex I and IV groups are similarly matched for baseline patient characteristics. Conclusion These results demonstrate reduced capacity to carry out OXPHOS in oesophageal and gastric adenocarcinoma is characteristic of more advanced cancer and results in worse patient outcomes. Further work is needed to determine if OXPHOS status impacts on neo-adjuvant therapy response and how to exploit OXPHOS deficiency therapeutically in oesophageal and gastric adenocarcinomas. The limitations of this preliminary work include small sample size and tissue derived from historic patients over a long period of time, during which treatment and outcomes for upper GI cancer have significantly changed.

Concurrent TB and HIV therapies effectively control clinical reactivation of TB during co-infection but fail to eliminate chronic immune activation.

The majority of Human Immunodeficiency Virus (HIV) negative individuals exposed to Mycobacterium tuberculosis (Mtb) control the bacillary infection as latent TB infection (LTBI). Co-infection with HIV, however, drastically increases the risk to progression to tuberculosis (TB) disease. TB is therefore the leading cause of death in people living with HIV (PLWH) globally. Combinatorial antiretroviral therapy (cART) is the cornerstone of HIV care in humans and reduces the risk of reactivation of LTBI. However, the immune control of Mtb infection is not fully restored by cART as indicated by higher incidence of TB in PLWH despite cART. In the macaque model of co-infection, skewed pulmonary CD4+ TEM responses persist, and new TB lesions form despite cART treatment. We hypothesized that regimens that concurrently administer anti-TB therapy and cART would significantly reduce TB in co-infected macaques than cART alone, resulting in superior bacterial control, mitigation of persistent inflammation and lasting protective immunity. We studied components of TB immunity that remain impaired after cART in the lung compartment, versus those that are restored by concurrent 3 months of once weekly isoniazid and rifapentine (3HP) and cART in the rhesus macaque (RM) model of LTBI and Simian Immunodeficiency Virus (SIV) co-infection. Concurrent administration of cART + 3HP did improve clinical and microbiological attributes of Mtb/SIV co-infection compared to cART-naïve or -untreated RMs. While RMs in the cART + 3HP group exhibited significantly lower granuloma volumes after treatment, they, however, continued to harbor caseous granulomas with increased FDG uptake. cART only partially restores the constitution of CD4 + T cells to the lung compartment in co-infected macaques. Concurrent therapy did not further enhance the frequency of reconstituted CD4+ T cells in BAL and lung of Mtb/SIV co-infected RMs compared to cART, and treated animals continued to display incomplete reconstitution to the lung. Furthermore, the reconstituted CD4+ T cells in BAL and lung of cART + 3HP treated RMs exhibited an increased frequencies of activated, exhausted and inflamed phenotype compared to LTBI RMs. cART + 3HP failed to restore the effector memory CD4+ T cell population that was significantly reduced in pulmonary compartment post SIV co-infection. Concurrent therapy was associated with the induction of Type I IFN transcriptional signatures and led to increased Mtb-specific TH1/TH17 responses correlated with protection, but decreased Mtb-specific TNFa responses, which could have a detrimental impact on long term protection. Our results suggest the mechanisms by which Mtb/HIV co-infected individuals remain at risk for progression due to subsequent infections or reactivation due of persisting defects in pulmonary T cell responses. By identifying lung-specific immune components in this model, it is possible to pinpoint the pathways that can be targeted for host-directed adjunctive therapies for TB/HIV co-infection.

Synchronous multifocal osteosarcoma: Report of 4 cases and literature review

BackgroundMultifocal osteosarcoma (MFOS) is rare, accounting for approximately 1.5 % of osteosarcomas, and can be synchronous (lesions within six months) or metachronous (lesions after six months). The etiology and optimal treatment for MFOS remain controversial. This report presents four patients with synchronous MFOS and reviews the literature. Case presentationCase 1: A 24-year-old female with low back pain was found to have multiple lytic bone lesions with increased FDG uptake in the vertebral column and pelvic bones. Biopsy confirmed osteoblastoma-like osteosarcoma. After chemotherapy, she is alive after 5 months.Case 2: A 6-year-old girl with right knee pain had a distal femur mass and a calcified inguinal lesion. Biopsies revealed osteoblastic osteosarcoma with metastatic lymph node involvement. Following chemotherapy and surgeries, she experienced recurrence and required further surgery. She is alive after 21 months.Case 3: A 4-year-old boy with a walking disability had a sclerotic bone lesion in the distal femur and additional lesions in the pelvis and acetabulum. Biopsy confirmed osteoblastic osteosarcoma. Despite treatment, he developed metastases and died 7 months after diagnosis.Case 4: A 9-year-old girl with right knee swelling had a sclerotic lytic lesion in the distal femur and an acetabular lesion. Biopsies confirmed chondroblastic osteosarcoma. After chemotherapy and surgery, she experienced recurrence and underwent pelvic resection. She died 24 months after diagnosis. ConclusionSynchronous MFOS is a highly aggressive osteosarcoma variant with a poor prognosis. Aggressive, individualized treatment may improve outcomes, particularly in metachronous cases. Further research is needed to enhance understanding and management of this rare condition.

Clinical characteristics, treatment and outcome of pembrolizumab-induced acute pancreatitis.

Acute pancreatitis (AP) is a rare adverse event of pembrolizumab with unclear clinical features. This study investigated the clinical features of pembrolizumab-induced AP to provide a reference for prevention and treatment. Case reports, case series and clinical studies of pembrolizumab-induced AP were collected by searching Chinese and English databases up to January 31, 2024. Thirty-one patients were included, with a median age of 59 years (range 39, 82). The median time from administration to onset of AP was 5.05 months (range 0.5, 16) and the median cycle was 7 cycles (range 1, 35). Twenty-two (71.0%) patients had elevated pancreatic amylase with a median value of 860 IU/L (range 105-12562), and 16 (51.6%) patients had elevated lipase with a median value of 282 IU/L (range 153-1034). Pancreatic biopsy showed neutrophil infiltration (9.7%) and lymphocyte infiltration (6.5%). Immunohistochemical staining showed CD8 dominated inflammatory infiltration (6.5%). The computed tomography showed diffuse enlargement (51.6%) and focal enlargement (51.6%) of the pancreas. Endoscopic ultrasound showed enlarged hypoechoic pancreas(16.1%). PET/CT showed increased FDG uptake (16.1%). The magnetic resonance cholangial pancreatography showed narrowing of main pancreatic duct (12.9%). AP symptoms and pancreatic enzymes improved after discontinuation of pembrolizumab and administration of steroids and infliximab. Clinicians should be aware that AP is a rare adverse reaction to pembrolizumab. Pembrolizumab induced AP can be initiated with steroids for control, and infliximab can be initiated with steroid-refractory AP.

Intraureteral Metastasis From Colon Cancer Mimicking Primary Ureteral Carcinoma on FDG PET/CT.

Hematogenous or lymphatic intraureteral metastasis from distant primary cancer is very rare. We present contrast-enhanced CT and FDG PET/CT findings in a case of intraureteral metastasis from colonic adenocarcinoma 3 years after colectomy. The intraureteral showed moderate enhancement on contrast-enhanced CT and increased FDG uptake on PET/CT mimicking a primary ureteral carcinoma. This case suggests that metastatic tumor of the ureter should be considered in the differential diagnosis in patients with hypermetabolic ureteral lesion and known malignancy.

Nasopharyngeal Mucoepidermoid Carcinoma: A Rare Case Report

Introduction : Mucoepidermoid carcinoma is one of the common malignancies of the salivary glands. Nasopharyngeal mucoepidermoid carcinoma cases are rare. The treatment of these rare cases depends on the stage of the tumor and its invasion into the surrounding tissues. Case: A 63-year-old male patient, who was followed up for thyroid papillary carcinoma in 2006, was referred to our clinic after incidentally detected asymmetrical thickening of the nasopharynx on the left as a result of brain MRI during medical oncology follow-ups. The patient had a complaint of pain in the left neck region for about a month. Excisional biopsy from the lymph node that increased FDG uptake in the left jugulodigastric region in PET/CT and multiple punch biopsy from the nasopharynx were performed. The patient, whose pathology resulted in mucoepidermoid carcinoma, was referred to oncology to receive radiochemotherapy. Discussion: Although rare, it should be kept in mind that in patients presenting with a mass in the nasopharynx, mucoepidermoid carcinoma may be present. Although there is information about treatment options in the studies carried out to date, prospective studies are needed for prognosis and treatment selection.

The Monocle Sign on 18 F-FDG PET Indicates Contralateral Peripheral Facial Nerve Palsy.

The aim of our study was to retrospectively analyze FDG PET/CT data in patients with facial nerve palsy (FNP) for the presence of the monocle sign. A total of 85 patients with unilateral FNP were included into our study, thereof 73 with peripheral FNP and 12 with central FNP. FDG uptake (SUV max , SUV mean , total lesion glycolysis) was measured in both orbicularis oculi muscles (OOMs). FDG uptake of paretic and nonparetic muscles was compared in patients with FNP (Wilcoxon test and Mann-Whitney U test) and was also compared with FDG uptake in 33 patients without FNP (Mann-Whitney U test). SUV max ratios of OOM were compared. A receiver operating characteristic curve and Youden Index were used to determine the optimal cutoff SUV max ratio for the prevalence of contralateral peripheral FNP. The SUV max ratio of OOM was significantly higher in patients with peripheral FNP compared with patients with central FNP and those without FNP (1.70 ± 0.94 vs 1.16 ± 0.09 vs 1.18 ± 0.21, respectively; P < 0.001). The SUV max ratio of OOM yielded an area under the curve (AUC) of 0.719 (95% confidence interval, 0.630-0.809), with an optimal cutoff of 1.41, yielding a specificity of 94.4% and a sensitivity of 44.1% for identifying contralateral peripheral FNP. One hundred percent specificity is achieved using a cutoff of 1.91 (sensitivity, 29.4%). Asymmetrically increased FDG uptake of the OOM (the "monocle sign") indicates contralateral peripheral FNP. A nearly 2-fold higher SUV max represents a practically useful cutoff.

The Dark Side of Activated Phosphoinositide 3-Kinase-δ Syndrome 2: A Story Rewritten through FDG-PET.

Background: Activated phosphoinositide 3-kinase-δ syndrome 2 (APDS2) is characterized by lymphoproliferation and increased risk of malignancy. FDG-PET/CT may represent a helpful diagnostic tool for differentiating these clinical features and correctly diagnosing inborn errors of immunity (IEI). Case report: We present the case of a female patient diagnosed with Hodgkin's lymphoma at 19 years of age, although atypical imaging aspects emerged: baseline FDG-PET/CT revealed several hot lymph nodes with a symmetrical distribution, and increased tracer uptake in spleen, axial, and appendicular bone marrow. Imaging repeated after chemotherapy and autologous stem cell transplantation showed persistent increased FDG uptake at multiple supradiaphragmatic nodes and in bone marrow. After the diagnosis of APDS2 and rapamycin treatment, FDG-PET/CT confirmed complete metabolic normalization of all sites. Conclusions: In the IEI scenario, FDG-PET/CT plays an effective role in differentiating malignant proliferation and immune dysregulation phenotypes. Atypical patterns at FDG-PET/CT should be interpreted as a red flag for the need of an early immunological evaluation.

Amelanotic melanoma detected by 18F-FDG PET-CT

BackgroundAmelanotic/hypomelanotic melanoma is an extremely rare cancer and accounts for less than 1/10,000 in the population. For losing and hypomelanotic pigment, amelanotic melanoma can lead to misdiagnosis with benign skin lesions. Therefore, early recognition and diagnosis is important to avoid a delay in treatment.Case presentationA 73-year-old man presented for a gradually enlarged nodule on the surface skin of the left crus, with no color change, ulceration, or bleeding. Malignant lesion was suspected based on computed tomography (CT) and magnetic resonance imaging (MRI), and biopsy was scheduled. Immunohistochemical (IHC) revealed amelanotic melanoma followed by biopsy.18Florine-fluoro-2-deoxy-2-d-glucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) was employed to explore whether there are metastases or not. 18F-FDG PET-CT showed increased FDG accumulation with standardized uptake value max (SUVmax) of 5.6 of the lesion, and no other lesions were detected. The patient refused to be hospitalized and died 12 months later.ConclusionThis case highlights the need of considering melanoma even if there is no color change. Increased FDG uptake from PET-CT is prone to be consistent with malignant disease as well as whole body scan is crucial in determining the accurate TNM stage. Moreover, prompt treatment according to guidelines is necessary even if the disease is at its early stage.

Examination of iatrogenic FDG accumulation after COVID-19 vaccination.

This study aimed to investigate the frequency of COVID-19 vaccine-induced reactive change and potential factors including blood type correlated with increased FDG uptake on positron emission tomography (PET)/computed tomography (CT). We evaluated 284 patients who underwent PET/CT between June and September 2021 and had a known history of COVID-19 vaccination. Information on the injection site, vaccine type, and adverse reactions was obtained. We visually assessed the presence or absence of accumulation in the axillary and supraclavicular lymph nodes and the deltoid muscles. We measured the maximum standardized uptake value (SUVmax) using semi-quantitative analysis. Our study included 158 males and 126 females aged 16-94. The median time between vaccination and PET/CT was 9 and 42days for patients who had received their first and second doses, respectively. We observed axillary lymph node accumulation, supraclavicular lymph node accumulation, and deltoid muscle accumulation in 98 (SUVmax 1.07-25.1), nine (SUVmax 2.28-14.5), and 33 cases (SUVmax 0.93-7.42), respectively. In cases with axillary lymph node (P = 0.0057) or deltoid muscle (P = 0.047) accumulation, the shorter the time since vaccination, the higher the FDG accumulation. Patients with axillary lymph node accumulation were significantly younger (P < 0.0001) and had a significantly higher frequency of adverse reactions such as fever (P < 0.0001) and myalgia (P = 0.002). No significant relationship was observed between blood type and the frequency of FDG accumulation. Logistic regression analysis also showed that age, gender, days since vaccination, and adverse reactions such as fever and myalgia were important factors for axillary lymph node accumulation. Our study found that FDG accumulation in the axillary lymph nodes and deltoid muscle was higher within a shorter time after vaccination, and axillary lymph node accumulation was higher in young patients, females, and those with adverse reactions of fever and myalgia. No significant relationship was observed between blood type and the frequency of FDG accumulation. Confirming the vaccination status, time since vaccination, and the presence of adverse reactions before PET may reduce false positives.

Desmoplastic small round cell tumor of bone revealed by 18F-FDG PET/CT: a case report with literature review.

A 50-year-old male presented with neck and shoulder pain. Chest CT and 18F-FDG PET/CT revealed osteolytic bone destruction in the left first rib and thoracic vertebrae with increased FDG uptake. Rib biopsy pathology indicated desmoplastic small round cell tumor (DSRCT).18F-FDG PET/CT can accurately locate the distribution of DSRCT and further guide the location of needle biopsy to assist the DSRCT.

Prospective Assessment of Fluorine-18-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography (FDG-PET/CT) for Early Identification of Checkpoint-Inhibitor-Induced Pseudoprogression.

The activity of immune checkpoint inhibitors (ICIs) in patients with metastatic melanoma is often monitored using fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scans. However, distinguishing disease progression (PD) from pseudoprogression (PsPD), where increased FDG uptake might reflect immune cell activity rather than tumor growth, remains a challenge. This prospective study compared the efficacy of dual-time point (DTP) FDG-PET/CT with modified response criteria (PERCIMT) in differentiating PsPD from PD. From July 2017-January 2021, 41 patients suspected to have PsPD on an evaluation scan were prospectively included (29 evaluable). A subsequent DTP FDG-PET/CT scan was conducted within 14 days, followed by a confirmatory FDG-PET/CT scan. Additionally, PERCIMT were applied. DTP FDG-PET/CT identified 24% with PsPD and 76% with PD. Applying PERCIMT criteria, 69% showed PsPD, while 31% had PD. On follow-up, 10 patients (34%) demonstrated confirmed PsPD, while 19 (66%) exhibited PD. The sensitivity and specificity of DTP FDG-PET/CT were 20% and 74%, respectively, and for PERCIMT this was 80% and 37%, respectively. Our findings suggest limited efficacy of DTP FDG-PET/CT in distinguishing PsPD from PD in ICI-treated patients with metastatic melanoma. The use of PERCIMT could complement clinical assessment and be incorporated in multidisciplinary team conferences for enhanced decision-making.

False Liver Metastasis by Positron Emission Tomography/Computed Tomography Scan after Chemoradiotherapy for Esophageal Cancer-Potential Overstaged Pitfalls of Treatment.

In patients with esophageal cancer undergoing neoadjuvant chemoradiotherapy (nCRT), subsequent restaging with F-18-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) can reveal the presence of interval metastases, such as liver metastases, in approximately 10% of cases. Nevertheless, it is not uncommon in clinical practice to observe focal FDG uptake in the liver that is not associated with liver metastases but rather with radiation-induced liver injury (RILI), which can result in the overstaging of the disease. Liver radiation damage is also a concern during distal esophageal cancer radiotherapy due to its proximity to the left liver lobe, typically included in the radiation field. Post-CRT, if FDG activity appears in the left or caudate liver lobes, a thorough investigation is needed to confirm or rule out distant metastases. The increased FDG uptake in liver lobes post-CRT often presents a diagnostic dilemma. Distinguishing between radiation-induced liver disease and metastasis is vital for appropriate patient management, necessitating a combination of imaging techniques and an understanding of the factors influencing the radiation response. Diagnosis involves identifying new foci of hepatic FDG avidity on PET/CT scans. Geographic regions of hypoattenuation on CT and well-demarcated regions with specific enhancement patterns on contrast-enhanced CT scans and MRI are characteristic of radiation-induced liver disease (RILD). Lack of mass effect on all three modalities (CT, MRI, PET) indicates RILD. Resolution of abnormalities on subsequent examinations also helps in diagnosing RILD. Moreover, it can also help to rule out occult metastases, thereby excluding those patients from further surgery who will not benefit from esophagectomy with curative intent.

Histiocytic necrotizing lymphadenitis with hemophagocytic lymphohistiocytosis in adults: A single-center analysis of 5 cases.

Histiocytic necrotizing lymphadenitis (HNL) is a self-limited inflammatory disease of unknown pathogenesis. A very small fraction of patients with HNL could develop hemophagocytic lymphohistiocytosis (HLH), a hyperinflammatory disorder. These patients are diagnosed as HNL with HLH (HNL-HLH). HNL-HLH in the pediatric population has been systemically studied, however, the clinical, laboratory, and radiological features and outcomes of adult patients with HNL-HLH remain to be explored. We aimed to explore the clinical, laboratory, and radiological features and outcomes of adult patients with HNL-HLH. We collected the clinical data of patients with HNL-HLH admitted to the First Affiliated Hospital of Nanjing Medical University from October 2010 to June 2015. All the patients underwent lymph node biopsy and have a pathological diagnosis of HNL. The age, gender, clinical presentation, lymph node signs, laboratory findings and imaging data, and pathological findings of the patients were collected. In this study, we reported five adult patients with HNL-HLH. All five patients showed enlarged lymph nodes and prolonged fever. Laboratory findings were consistent with the diagnosis of HLH. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) showed enlarged lymph nodes with increased FDG uptake and splenic hypermetabolism could be present. All the patients responded well to corticosteroids and had a good prognosis. Two of the five patients were diagnosed with systemic lupus erythematosus during the follow-up. Our study demonstrated that adult patients with HNL-HLH showed distinct clinical, laboratory, and radiological features. And the prognosis is good and patients could be managed with steroids and supportive care.