Increased 18F-fluorodeoxyglucose Uptake Research Articles

An Exceptional Cause of Increased 18F-Fluorodeoxyglucose Uptake on PET/CT in a Thyroid Nodule.

A 41-year-old female underwent a cervical spine CT for the workup of posterior neck pain irradiating to the shoulders for several months. An incidental thyroid nodule was found and classified as Bethesda III on the Fine-needle aspiration cytology (FNAC) results. Three months later, the patient developed mild shortness of breath, dry cough, and fever. Chest X-ray revealed a mild enlargement in the bilateral hilar regions. CT showed mediastinal and bilateral hilar enlarged lymph nodes and pulmonary micronodules. The workup was further completed with a 18F-FDG PET/CT, showing intense FDG uptake in the mediastinal and bilateral hilar lymph nodes and increased uptake in the thyroid nodule. Endobronchial Ultrasound-guided Transbronchial needle aspiration (EBUS-TBNA) of a left hilar lymph node showed epithelioid non-necrotizing granulomas. Because of the FNAC results, size of the nodule and tracheal shift, thyroid lobectomy was performed one month later. Histopathological results also revealed multiple non-necrotizing epithelioid granulomas, suggesting systemic sarcoidosis with involvement of the thyroid. To our knowledge, this is the first report of thyroid sarcoidosis detected on 18F-FDG PET/CT. Although an increased FDG uptake in a thyroid nodule is usually suggestive of thyroid malignancy, toxic nodule, or follicular hyperplasia, our case report shows that it could also suggest thyroid sarcoidosis.

Nerve Root Metastasis of Breast Carcinoma Detected by Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scan.

A 35-year-old woman with history of breast cancer was referred to our department for restaging by F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan. Aside from multiple other FDG-avid metastatic lesions, a segmental increased FDG uptake was visualized along the asymmetrically thicker left first sacral nerve root, highly concerning for metastatic disease, which was confirmed by the subsequently performed magnetic resonance imaging. Our case highlights the capability of FDG PET/CT scan in the correct diagnosis of the extremely rare phenomenon of nerve root metastasis as well as the importance of differentiating FDG-avid lumbosacral nerve roots from adjacent skeletal metastases.

An Unusual Case of Intermittent Fever With Multiple Liver Lesions

Question: A 46-year-old man with a history of hypertension presented to our hospital with a chief compliant of intermittent fever for 2 weeks. He denied a history of nausea, vomiting, abdominal pain, diarrhea, abdominal distention, loss of appetite, or weight loss. Physical examination on admission was unremarkable. Laboratory studies showed white blood cells 15.32 × 109/L (reference 3.5–9.5 × 109/L) with 38.3% (reference 0.4%–8.0%) eosinophils, C-reactive protein 49.72 mg/L (reference 0–10 mg/L), and erythrocyte sedimentation rate 44 mm/h (reference 0–15 mm/h). No parasite eggs or larvae were found in microscopic examination of direct smears of the stool. Liver function tests revealed alanine transaminase 50.5 IU/L (reference 9–50 IU/L), alkaline phosphatase 134 IU/L (reference 15–40 IU/L), gamma-glutamyltransferase 224 IU/L (reference 10–60 IU/L), total protein 40.1 g/L (reference 65–85 g/L), and albumin 21.6 g/L (reference 40–55 g/L). His renal function and tumor markers, such as alpha-fetoprotein, carcino-embryonic antigen, and carbohydrate antigen 19-9 were all within normal ranges. Tests for hepatitis B, hepatitis C, antinuclear antibodies, extractable nuclear antigen antibodies, and anti–neutrophil cytoplasm antibodies were all negative. No significant abnormalities were detected on electrocardiography, echocardiography, and chest computed tomography (CT). Routine ultrasound revealed multiple hypoechoic areas with unclear borders in the left lobe and right posterior lobe of the liver. Magnetic resonance imaging (MRI) of the liver was subsequently performed and showed multiple nodular or clumpy lesions as low signal intensity on T1-weighted imaging (WI) (Figure A) and high signal intensity on fat-suppressed T2-WI (Figure B) and diffusion WI (Figure C). Contrast-enhanced scan exhibited slightly heterogeneous enhancement (Figure D) or annular enhancement (Figure E). MRI did not indicate any anatomic malformations or intrahepatic or extrahepatic bile duct dilation. Positron emission tomography–computed tomography (PET-CT) revealed increased 18F-fluorodeoxyglucose uptake in the liver lesions (maximum standardized uptake value 3.8–5.2) (Figure F). The patient subsequently underwent CT-guided liver biopsy. Histopathology demonstrated chronic hepatic inflammation with prominent eosinophilic infiltration in portal areas and some acinar areas (Figure G).

Castleman disease of the pancreas mimicking pancreatic malignancy on 68Ga-DOTATATE and 18F-fluorodeoxyglucose positron emission tomography/computed tomography: A case report

BACKGROUNDCastleman disease is an uncommon nonclonal lymphoproliferative disorder, which frequently mimics both benign and malignant abnormalities in several regions. Depending on the number of lymph nodes or regions involved, Castleman disease (CD) varies in diagnosis, treatment and prognosis. It rarely occurs in the pancreas alone without any distinct clinical feature and tends to be confused with pancreatic paraganglioma (PGL), neuroendocrine tumors (NETs), and primary tumors, thus impeding proper diagnosis and treatment.CASE SUMMARYA 28-year-old woman presented with a lesion on the neck of the pancreas, detected by ultrasound during a health examination. Physical examination and laboratory findings were normal. The mass showed hypervascularity on enhanced computed tomography (CT), significantly increased 18F-fluorodeoxyglucose uptake on positron emission tomography (PET)/CT, and slightly increased somatostatin receptor (SSTR) expression on 68Ga-DOTATATE PET/CT, suggesting no distant metastases and subdiagnoses such as pancreatic PGL, NET, or primary tumor. Intraoperative pathology suggested lymphatic hyperplasia, and only simple tumor resection was performed. The patient was diagnosed with the hyaline vascular variant of CD, which was confirmed by postoperative immunohistochemistry. The patient was discharged successfully, and no recurrence was observed on regular review.CONCLUSIONHigh glucose uptake and slightly elevated SSTR expression are potentially new diagnostic features of CD of the pancreas.

Increased 18F-fluorodeoxyglucose uptake in the cardiac atria: an evidence for increased atrial inflammation in patients with atrial fibrillation?

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial inflammation and fibrotic remodelling underlie the pathophysiology of atrial cardiomyopathy, which is associated with the development of atrial fibrillation (AF) and atrial flutter (AFL). 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) has been used to detect inflammatory processes. Recent studies have revealed an increased FDG-uptake in the atria of patients with AF, but also in patients with diagnosis of cardiac sarcoidosis with ventricular inflammation. Purpose This study aimed to assess the capability of PET/CT to detect and quantify the degree of atrial inflammation (FDG-uptake) in a population with dedicated cardiac FDG-PET/CT. Methods We investigated 101 patients suspected of sarcoidosis (57±12 years, 72% male) who underwent 18F-FDG PET/CT scan with dedicated cardiac specific preparation (heparin infusion, 12 hours fasting, and high-fat low-carbohydrate diet). We excluded patients with active ventricular cardiac sarcoidosis or undergoing high-dose immunosuppressive therapy (prednisolone ≥20mg/day or prednisolone combined with other immunotherapy like methotrexate). We measured the maximum standardized uptake value (SUVmax) in atrial myocardium and mean standardized uptake value (SUVmean) in blood pool and calculated the target-to-background ratio (TBR) of SUVmax in atrial myocardium to SUVmean in blood pool. All medical records, ECG data on arrhythmia type and diagnosis of systemic sarcoidosis (with absence of ventricular involvement) were used for the analysis. Sarcoidosis was diagnosed based on the criteria established in 2006 by the Japanese Ministry of Health and Welfare. The collected data were sorted according to presence of arrhythmia and systemic sarcoidosis and TBR of each group were compared. Results AF or AFL was found in 30/101 patients. Systemic sarcoidosis was found in 37/101 patients. Patients with known AF/AFL had significantly increased TBR within the atrial tissue compared to those without AF/AFL: (median: 1.26, 1st-3rd quartile: 1.20-1.33) versus (median: 1.22, 1st-3rd quartile: 1.14-1.25; p = 0.004; figure A). Arrhythmia-associated atrial inflammation was consistently observed, independently of presence of concomitant systemic sarcoidosis (figure B). Patients with both atrial arrhythmias and systemic sarcoidosis had the highest atrial inflammation level, as identified by TBR (figure B). Conclusion Development of atrial fibrillation or flutter is associated with an increased atrial FDG-uptake as metabolic marker of atrial inflammation. The level of atrial inflammation is further enhanced by additional presence of systemic sarcoidosis.

Omicron Variant of COVID-19: Imaging Pattern on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

We report a case of omicron infection in a biopsy-proven case of carcinoma breast sent for staging F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) during the omicron COVID wave. FDG PET/computed tomography (CT) revealed increased FDG uptake in nasopharyngeal, oropharynx, and tonsillar regions and bilateral cervical lymph nodes along with uptake in primary carcinoma and locoregional lymph nodes. Based on the clinical history and specific pattern of FDG PET/CT findings (as suggested by SNMMI Taskforce), COVID history and reverse transcription polymerase chain reaction positivity was elicited.

PET/CT helps to determine treatment duration in patients with resected as well as inoperable alveolar echinococcosis.

The aim of the study was to determine the role of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) at the end of benzimidazole therapy in alveolar echinococcosis. A total of 22 patients undergoing PET/CT at the end of benzimidazole therapy were retrospectively registered. Maximum standardized uptake values (SUVmax) were measured in remaining echinococcus manifestations and compared to normal liver tissue. Long-term clinical follow-up was performed, and recorded data included laboratory parameters, clinical information and imaging. All patients had no detectable levels of Em-18 antibodies and all echinococcus manifestations were negative on PET/CT, i.e. without focally increased FDG uptake or uptake higher than normal/non-infected liver tissue. All manifestations displayed significantly less FDG-uptake than normal liver tissue, i.e. SUVmax 1.8 (interquartile range (IQR) 1.5-3.5) vs. 3.0 (IQR 2.6-5.7), (p<0.001). Patients were clinically followed for a median of 9.5years (IQR 6.5-32.0years) after their initial diagnosis and for 4.5years (IQR 3.0-14.0years) after discontinuation of benzimidazole therapy. No patient showed signs of recurrent infection at the last clinical visit. The 10-year and 20-year freedom from all-cause mortality was 95.0% (95% confidence interval 69.5% - 99.3%), for both. Two events occurred in 292 patient years of follow-up; i.e. two patients (9%) died, one because of pancreatic cancer, the other one because of unknown reasons with no detectable antibody levels. Negative FDG-PET/CT results combined with no detectable levels of Em-18 antibodies may allow for the safe discontinuation of benzimidazole therapy in patients with alveolar echinococcosis.

P1697 A rare case: primary cardiac sarcoma in the left and right atrium presenting with dispnea due to mitral valvular obstruction

Abstract Introduction Primary cardiac tumors are extremely rare; the incidence is approximately 0.001% to 0.03%. Malignant tumors account for 25% of primary cardiac tumors, and among those, sarcomas are the most prevalent. We report a case of primary cardiac sarcoma presenting with dyspnea due to mitral valvuler obstruction. Case Report A 41-year-old woman was admitted to the hospital with dyspnea for 8 months without any obvious causes. She was healthy previous and without family history. Physical examination was normal. Thorax computed tomography (CT) scan was performed with the doubt of pulmonary disease. A 1x1 cm hypodense nodule was detected in superior segment of the right lower lobe lung. Positron emission tomography-computed tomography (PET-CT) revealed a 1*1 cm nodule in the lung. And also increased 18F-fluorodeoxyglucose uptake was observed in the left scapula, left iliac wing and right 4th rib, likely due to metastasis. Biopsy from the lesion of iliac wing was performed. Pathologic examination was primarily compatible with the malign mesenchymal tumor and sarcoma infiltration; but malignant epithelial tumor and metastasis of carcinoma could not be ruled out. Magnetic resonance imaging of the lung was performed to find the origin of the metastatic tumor. A 8,6 x 5,3 x 5,1 cm mass filling the right and left atria was detected.It was extending from the right atrium to the superior vena cava and also from the left atrium to the right inferior and superior pulmonary venules. The image of mass was compatible with sarcoma. Transthoracic echocardiography was performed. A mass in the left and right atrium was detected. It was filling the left atrium. Due to the mass, the maximum mitral gradient was 21 mm Hg and the mean mitral gradient was 10 mm Hg, as if there was mitral stenosis.Systolic pulmonary artery pressure was 40 mmHg. Mild mitral insufficiency was detected. The patient was evaluated with the department of oncology and cardiovascular surgery. It was decided that the mass was inoperable. So transesophageal echocardiography was not performed. It was thought that, the mass was primary cardiac sarcoma, pulmonary nodule and bone lesions were metastasis of this primary cardiac sarcoma. So chemotherapy protocol (ifosfamide,adriamycin,mesna) was started. Conclusion Cardiac tumors have many clinical presentations. Early stages of the disease are often asymptomatic. In advanced stages, patients present with symptoms of the classic triad (intracardiac obstruction, systemic embolization, constitutional symptoms) Symptoms are often non-spesific; so diagnostic suspicion is very important. Although cardiac sarcoma therapy includes complete surgical excision, followed by radiotherapy and chemotherapy, prognosis is still poor. Surgery can offer dramatic palliation of symptoms in cases of valvular obstruction. In conclusion, it remains clear that early diagnosis and treatment are extremely important because of their prognostic and therapeutic value. Abstract P1697 Figure.

Common features of F-18 FDG PET/CT findings in Scrub Typhus: prospective study before and after antibiotics therapy

Scrub typhus is an acute febrile illness caused by obligate intracellular organism Orientia tsutsugamushi. While there have been many reports on the evaluation of disease activity and infectious diseases using F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), the clinical value of FDG PET/CT in scrub typhus has not been fully investigated. We enrolled 17 patients who were 18 years of age or older and clinically suspected of having scrub typhus with eschar. Clinical assessments, blood samples, and FDG PET/CT images were obtained at enrolment and again after 3 weeks. The median age of the patients was 65 years; 9 (52.9%) patients were male. On initial FDG PET/CT, the eschars showed markedly increased FDG uptake on PET imaging that improved after treatment. Generalized lymphadenopathy and splenomegaly with high FDG uptake were observed in all patients. On follow-up FDG PET/CT after appropriate therapy, FDG uptake and sizes of eschar, lymph nodes, and spleen were markedly decreased. As far as we are aware, this is the first investigation with multiple patients of FDG PET/CT in scrub typhus and the demonstration of clinical utility. FDG PET/CT imaging of scrub typhus could provide useful information about the clinical features before and after antibiotic treatment.

Positron emission tomography/computed tomography detection of increased 18F-fluorodeoxyglucose uptake in the cardiac atria of patients with atrial fibrillation

BackgroundDirect evidence of inflammatory activity in the atria of patients with atrial fibrillation (AF) is scarce. We assessed the capability of positron-emission tomography/computed tomography (PET/CT) to diagnose AF based on fluorodeoxyglucose (FDG) uptake in the atrial wall. Methods and resultsAmong 8233 patients who underwent FDG-PET/CT as work-up for malignancies, we identified 180 consecutive patients with AF (2.2%). Of those, we selected 137 patients who had fasted >12 h before FDG injection for inclusion in the experimental group (88 men and 49 women; age: 72.7 ± 8.9 years). Controls were 62 age- and sex-matched patients without AF. For visual analysis, we used a 4-point grading system. For quantitative analysis, we used the maximum standard uptake value (SUVmax) in the left (LA) and right atrial (RA) myocardium and the target-to-background ratio (TBR) of SUVmax to blood pool activity. The sensitivity, specificity, and positive-predictive value for detecting AF visually were 54.0%, 95.2%, and 96.1%, respectively; for quantitative analysis, the respective values were 65.7%, 75.8%, and 85.7%. Multivariable analysis of 11 clinical and imaging variables showed significant associations with RA SUVmax (odds ratio [OR]: 14.353, P = 0.026) and LA volume (OR: 1.371, P = 0.0001). The RA TBR was greater in cases with persistent AF than in those with paroxysmal AF (P < 0.0001). Pathological investigation of 4 autopsy hearts confirmed infiltration of extravascular macrophages and lymphocytes in the regions with FDG uptake. ConclusionsHigher atrial FDG uptake was associated with AF. PET/CT could be a useful tool for detecting local inflammation in the atria with AF.

Characterization of the Electroanatomic Substrate in Cardiac Sarcoidosis: Correlation With Imaging Findings of Scar and Inflammation.

This study sought to characterize the electroanatomic (EAM) substrate in patients with cardiac sarcoidosis (CS) and ventricular tachycardia and its relationship to imaging findings of inflammation and fibrosis. CS is characterized by coexistence of active inflammation and replacement fibrosis. A total of 42 patients with CS based on established criteria and ventricular tachycardia underwent high-density EAM mapping. Abnormal electrograms (EGM) were collected and independently classified as multicomponentfractionated, isolated, late, and split according to standard criteria and regardless of the peak-to-peak bipolar/unipolar voltage. A total of 29 patients (69%) underwent pre-procedural cardiac magnetic resonance (CMR) and positron emission tomography (PET)/computed tomography (CT). The distribution of EAMsubstrate was correlated with regions of late gadolinium enhancement (LGE) on CMR and increased 18F-fluorodeoxyglucose uptake on PET/CT. Of 21,451 bipolar and unipolar EGM, 4,073 (19%) were classified as abnormal with a predominant distribution in the basal perivalvular segments and interventricular septum. Using the standard bipolar (<1.5 mV) and unipolar (<8.3mV for left ventricle<5.5 mV for the right) voltage cutoff values, 40% and 22% of the abnormal EGM were located outside the EAM low-voltage areas, respectively. LGE was present in 26 of 29 patients (90%), whereas abnormal 18F-fluorodeoxyglucose uptake in 14 of 29 patients (48%) with imaging. Segments with abnormal EGM had more LGE-evident scar transmurality [median: 24% (interquartile range [IQR]: 4% to 40%) vs. median: 5%(IQR: 0% to 15%); p< 0.001] and lower metabolic activity (median: 20 g glucose [IQR: 14 g to 30 g] vs. median: 29 g glucose [IQR: 18 g to 39 g]; p< 0.001). Overall, the agreement between the presence of abnormal EGM was higher with the presence of LGE (κ= 0.51; p< 0.001) than with the presence of active inflammation (κ=-0.12; p= 0.003). In patients with CS and ventricular tachycardia, pre-procedural imaging with CMR and PET/CT can be useful in detecting EAM abnormalities that are potential targets for substrate ablation. Abnormal EGM were more likelylocated in segments with more scar transmurality (LGE) at CMR and a lower degree of inflammation on PET.

Extracellular matrix protein 1 promotes cell metastasis and glucose metabolism by inducing integrin β4/FAK/SOX2/HIF-1α signaling pathway in gastric cancer.

Extracellular matrix protein 1 (ECM1) is related to strong invasiveness and poor prognosis in major malignancies, but the underlying mechanism remains unknown. Here we aimed to elucidate the function of ECM1 on cell metastasis and glucose metabolism in gastric cancer (GC). The level of ECM1 in sera and tissues of patient with GC were positively correlated with tumor invasion and recurrence. Genetic manipulation of ECM1 expression affected cell metastasis and glucose metabolism in GC cell lines. Enhanced ECM1 expression facilitated gene expression levels associated with epithelial-mesenchymal transition (EMT) and glucose metabolism. Interestingly, our results indicated that ECM1 directly interacted with integrin β4 (ITGB4) and activated ITGB4/focal adhesion kinase (FAK)/glycogen synthase kinase 3β signaling pathway, which further induced the expression of transcription factor SOX2. Aberrant expression of SOX2 altered gene expression of EMT factors and glucose metabolism enzymes. Furthermore, SOX2 enhanced hypoxia-inducible factor α (HIF-1α) promoter activity to regulate glucose metabolism. The micro-positron emission tomography/computed tomography imaging of xenograft model showed that ECM1 substantially increased 18F-fluorodeoxyglucose uptake in xenograft tumors. Using in vivo mouse tail vein injection experiments, ECM1 was also found to increase in lung surface metastasis. These findings provide evidence that ECM1 regulates GC cell metastasis and glucose metabolism by inducing ITGB4/FAK/SOX2/HIF-1α signal pathway and have important implications for the development of therapeutic target to prevent tumor metastasis and recurrence.

Radiation-induced liver injury mimicking liver metastases on FDG-PET-CT after chemoradiotherapy for esophageal cancer : Aretrospective study and literature review.

For esophageal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), restaging using F‑18-fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET-CT) following nCRT can detect interval metastases, including liver metastases, in almost 10% of patients. However, in clinical practice, focal FDG liver uptake, unrelated to liver metastases, is observed after chemoradiotherapy. This radiation-induced liver injury (RILI) can potentially lead to overstaging. Asystematic search for potential cases of RILI after (chemo)radiotherapy for esophageal cancer was performed in the electronic reports from all PET-CT scans made between 2006 and 2015 in our hospital. Additional data about potential cases were obtained from the electronic medical records. Aliterature review of RILI was also performed. Of 205 patients undergoing nCRT, 6cases with localized increased FDG uptake in the caudate or left liver lobe following nCRT for esophageal cancer were identified. None of these patients had signs of liver metastases with additional imaging, during surgery, on biopsy, or during follow-up (range 11-46months). At our institute, the incidence of RILI after neoadjuvant chemoradiotherapy for esophageal cancer was 3%. In the literature, RILI is described in about 8% of patients at the time of restaging. FDG-avid lesions occur in the high radiation dose area, usually corresponding to the caudate or left liver lobe. FDG accumulation in the caudate or left liver lobe after CRT in the area that received ahigh radiation dose may be caused by metastases or RILI. Awareness of the pitfall of high FDG uptake in RILI is crucial to avoid misinterpretation and overstaging.

Clinical utility of 18 F-fluorodeoxyglucose/positron emission tomography in diagnosis of immunoglobulin G4-related sclerosing sialadenitis.

The aim of this study was to evaluate the utility of 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for accurately diagnosing immunoglobulin G4-related sclerosing sialadenitis (IgG4-SS). Retrospective cohort study. We reviewed the records of 64 patients with IgG4-SS (35 male and 29 female patients) and 10 patients with clinically suspected IgG4-SS. Pathological diagnoses of patients clinically suspected with IgG4-SS included four cases of malignant lymphoma, one case of multicentric Castleman disease, one case of Sjögren's syndrome, and four cases of sialadenitis. All patients underwent submandibular gland (SMG) biopsies and baseline FDG-PET/CT evaluation. Clinical, serological, pathological, and PET/CT findings were analyzed. We also investigated maximum standardized uptake values (SUVmax) in the salivary glands of 15 patients with malignant disease of the salivary glands during the same period. Increased FDG uptake in the SMG and parotid gland was found in 63 (98%) and 23 (35%) patients with IgG4-SS, respectively. FDG uptake of the bilateral SMG and unilateral SMG was recorded in 57 patients (89%) and six patients (9%), respectively. Mean SUVmax in patients with malignant disease of the salivary glands was significantly higher than that in patients with IgG4-SS (P = .035). We defined a positive test for IgG4-SS diagnosis as high SMG FDG uptake and serum IgG4 level ≥135 mg/dL, resulting in a sensitivity, specificity, and accuracy of 96.9%, 90.0%, and 86.4%, respectively. FDG-PET/CT findings in combination with serological and clinical findings may have the capacity to diagnose IgG4-SS and lead to less-invasive biopsy procedures. 4. Laryngoscope, 128:1120-1125, 2018.

Pulmonary artery intimal sarcoma misdiagnosed as pulmonary embolism: A case report.

Intimal sarcoma of the pulmonary artery is rare, but false diagnosis of this sarcoma as pulmonary embolism is not infrequent. The present study reports a case of pulmonary artery intimal sarcoma misdiagnosed as pulmonary artery embolism in a 37-year-old female patient. The patient was admitted to the cardiac intensive care unit of Guangdong General Hospital (Guangzhou, China) with the complaint of progressive exertional dyspnea over the past two years. Multi-slice spiral computed tomography, transthoracic echocardiography, right-heart catheterization and cardiac magnetic resonance imaging revealed mimicking severe pulmonary embolism in the pulmonary trunk and right pulmonary artery, with symptoms including chest pain, cough and breathing difficulties. In addition, positron emission tomography-computed tomography results did not identify increased 18F-fluorodeoxyglucose uptake and failed to distinguish whether the mass was a thrombus or a malignancy. The patient was diagnosed with pulmonary embolism and a subcutaneous injection of 5,000 AxaIU enoxaparin sodium (100 AXAIU/kg) was administered every 12 h, but no improvement was achieved after 5 days of treatment. Finally, pulmonary endarterectomy was performed to relieve the worsening clinical symptoms. The clinicopathological diagnosis was pulmonary artery intimal sarcoma with poor clinical outcome. For this type of tumor with fatal prognosis, early and correct diagnosis may lead to appropriate intervention and prolong survival.

Paraneoplastic Sarcoidosis in Multiple Myeloma

Sarcoidosis predominantly affects the lungs, intrathoracic lymph nodes, and eyes; it less frequently affects the musculoskeletal system. We herein report a case of paraneoplastic sarcoidosis in a patient presenting with multiple myeloma. The patient developed ocular sarcoidosis and showed an increased 18F-fluorodeoxyglucose uptake in the mediastinal lymph nodes and vertebral column. A lymph node specimen showed the histological features of sarcoidosis, while an examination of the vertebral tumor revealed myeloma. Although the simultaneous occurrence of sarcoidosis and myeloma is extremely rare, our case indicates the importance of exculing any underlying malignancies before establishing a diagnosis of skeletal sarcoidosis when bone lesions are observed at unusual sites.

18F-fluorideoxyglucose positron emission tomography/computed tomography imaging: Artifacts and pitfalls

"F-fluorodeoxyglucose, being a radiolabeled glucose analogue, is a marker of glucose metabolism indicator. Since glucose uptake is increased in malignant tumors, its major application is in oncology. However, an increased 18F-fluorodeoxyglucose uptake is found in various benign tumors, granulomatous diseases, tuberculosis, inflammation, infection. A healing process may be interpreted as a false positive finding. In contrast, some types of renal cell cancers and lymphomas, neuroendocrine tumors, colonic mucinous adenocarcinomata, hepatocellular carcinomas, prostate cancer, and carcinoid tumors have low "F-fluorodeoxyglucose avidity which may give a misleading false negative result. In addition, an increased "F-fluorodeoxyglucose uptake in the bone marrow may be seen in oncologycal patients following various types of therapy. Besides the advantages of hybrid positron emission tomography-computed tomography imaging, this dual-modality scanning may produce their own specific artifacts due to different causes, such as metallic implants, respiratory motion, contrast medium and truncation. Proper patient preparation is required to minimize the potential artifactual uptake patterns that make reporting difficult. It is important to learn about proper quality control, imaging and reconstruction and to be familiar with potential artifacts and, pitfalls for the accurate interpretation of "F-fluorodeoxyglucose positron emission tomography-computed tomography.

Lymphadenopathy by Scrub Typhus Mimicking Metastasis on FDG PET/CT in a Patient with a History of Breast Cancer.

We report the case of a 60-year-old woman with left-sided breast cancer who showed lymphadenopathy mimicking metastatic lesions. She underwent surveillance (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after treatment. PET/CT demonstrated multiple lymphadenopathies with increased FDG uptake, most notably in the right axilla. She had an eschar on the right axillary area, and her serologic test was positive for anti-Orientia tsutsugamushi IgM antibody. Ten months after the treatment, follow-up FDG PET/CT and ultrasonography showed improvement in generalized lymphadenopathy.

Solitary plasmacytoma of the uvula

A 64-year-old gentleman presented to an otolaryngologist complaining of feeling a foreign body in his throat for several weeks. He had no pain, no dysphagia, nor odynophagia. In general, he was in good health. On physical exam, a mass could be seen on the posterior aspect of the uvula in the oropharynx (Image 1). A biopsy surprisingly revealed a plasmacytoma, composed of sheets of atypical plasma cells expressing CD56 and CD138 (Image 2). The patient underwent a complete evaluation for plasma cell dyscrasia. Serum electrophoresis with immunofixation revealed a minute lambda band too small to quantify. A 24 hr urine immunofixation revealed no monoclonal proteins. Other studies included normal free serum light chains (kappa-1.06 mg/dL, lambda 1.16 mg/dL ratio 0.9138), Hgb 15.7 g/dL, erythrocyte sedimentation rate 5 MM/hr, Cre 1.13 mg/dL, Albumin 4.3 g/dL, Calcium 9.2 mg/dL. A bone marrow core biopsy and aspirate showed no increase in plasma cells and no evidence of a monoclonal plasma cell population. Skeletal Survey with standard X-rays showed no lytic bone lesions. The patient also underwent a PET-CT scan that showed only the solitary focus in the oropharynx with increased 18F-fluorodeoxyglucose uptake. An MRI of the head showed no other lesions in the nasopharynx or sinuses. Therefore, a diagnosis of Solitary Extraosseous Plasmacytoma (SEP) was made. Treatment consisted of 50Gy of radiation to the lesion on the soft palate and 42.5Gy to the first echelon draining lymph nodes, administered via intensity-modulated radiation therapy (IMRT) to limit toxicity to the parotid gland, sublingual glands, and oral cavity (Image 3). Six weeks postradiation, clinically the lesion had completely regressed, and serum immunofixation no longer detected a minute lambda band. Post treatment PET-CT was negative. He will continue ongoing serologic surveillance and direct laryngoscopy at 3 to 6 month intervals and will be followed indefinitely. In contrast to Osseous (Medullary) Solitary Plasmacytoma, which carries a ∼50% risk of eventually developing Multiple Myeloma, the risk of developing Multiple Myeloma in patients with SEP is lower, estimated at between 10 and 20%. SEP commonly involves the upper respiratory tract and oropharynx as in this case, and has been reviewed extensively 1-6. Currently, the standard treatment approach for SEP is definitive radiation therapy, with a dose of >45 Gy of radiation therapy to the lesion 1, 4. This results in local control rates of ∼90%. Radiation of regional draining lymph nodes has been recommended for lesions involving the soft tissues of the head and neck 2. Patients who continue to display a monoclonal gammopathy post radiation are considered higher risk for either local relapse or eventual evolution to Multiple Myeloma. All patients require close ongoing follow-up.

A Solitary Mixed Squamous Cell and Glandular Papilloma of the Lung

Mixed squamous cell and glandular papilloma (mixed papilloma) of the lung is exceedingly rare, with only 18 cases reported in the literature. Herein, we report a case of mixed papilloma and its associated immunohistochemical and positron emission tomographic (PET) findings. A 60-year-old Japanese male with a smoking history of 40 pack-years presented with a smooth-edged pulmonary lesion in the right S5 segment on computed tomography (CT). F18-fluorodeoxyglucose (FDG) PET revealed abnormally increased FDG uptake in the mass (maximum standardized uptake value, 3.4). We performed right middle lobectomy and combined partial resection of the S8 segment. The 1.8-cm tumor that filled the enlarged lumen of the B5b was histologically diagnosed as mixed papilloma. Immunohistochemically, the pseudostratified columnar epithelium was positive for cytokeratin (CK) 5/6 and CK7. p40 positivity was predominant in the basal and squamous cells. Thyroid transcription factor-1 and carcinoembryonic antigen were negative on immunostaining. Malignant features were absent. The postoperative course has been uneventful for 3 months after the surgery. No recurrences were reported after the surgical resection of the mixed papilloma. Therefore, surgical resection may be considered the mainstay of curative treatment.