F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.
*Artifacts ; False Positive Reactions ; Female ; Fluorodeoxyglucose F18/*administration & dosage/diagnostic use/pharmacokinetics ; Humans ; Lung/metabolism/radiography/*radionuclide imaging ; Male ; Middle Aged ; Multimodal Imaging/methods ; Positron-Emission Tomography/*methods ; Pulmonary Embolism/radiography/*radionuclide imaging ; Radiopharmaceuticals/*administration & dosage/diagnostic use/pharmacokinetics ; Tomography, X-Ray Computed/methods ; Young Adult

OBJECTIVE: To identify CT and FDG-PET features associated with epidermal growth factor receptor (EGFR) protein overexpression, and to evaluate whether imaging features and EGFR-overexpression can help predict clinical outcome. MATERIALS AND METHODS: In 214 patients (M : F = 129 : 85; mean age, 63.2) who underwent curative resection of stage I non-small cell lung cancer, EGFR protein expression status was determined through immunohistochemical analysis. Imaging characteristics on CT and FDG-PET was assessed in relation to EGFR-overexpression. Imaging features and EGFR-overexpression were also evaluated for clinical outcome by using the Cox proportional hazards model. RESULTS: EGFR-overexpression was found in 51 patients (23.8%). It was significantly more frequent in tumors with an SUVmax > 5.0 (p < 0.0001), diameter > 2.43 cm (p < 0.0001), and with ground glass opacity < or = 50% (p = 0.0073). SUVmax > 5.0 (OR, 3.113; 95% CI, 1.375-7.049; p = 0.006) and diameter > 2.43 cm (OR, 2.799; 95% CI, 1.285-6.095; p = 0.010) were independent predictors of EGFR overexpression. Multivariate analysis showed that SUVmax > 4.0 (hazard ratio, 10.660; 95% CI, 1.370-82.966; p = 0.024), and the presence of cavitation within a tumor (hazard ratio, 3.122; 95% CI, 1.143-8.532; p = 0.026) were factors associated with poor prognosis. CONCLUSION: EGFR-overexpression is associated with high SUVmax, large tumor diameter, and small GGO proportion. CT and FDG-PET findings, which are closely related to EGFR overexpression, can be valuable in the prediction of clinical outcome.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Non-Small-Cell Lung/metabolism/mortality/*radiography/*radionuclide imaging ; Chi-Square Distribution ; Female ; Fluorodeoxyglucose F18/therapeutic use ; Humans ; Lung Neoplasms/metabolism/mortality/*radiography/*radionuclide imaging ; Male ; Middle Aged ; Neoplasm Staging ; Positron-Emission Tomography/*methods ; Proportional Hazards Models ; ROC Curve ; Radiopharmaceuticals/diagnostic use ; Receptor, Epidermal Growth Factor/*metabolism ; Statistics, Nonparametric ; Survival Rate ; Tomography, X-Ray Computed/*methods

Basaloid squamous cell carcinoma is a rare and aggressive variant of squamous cell carcinoma, which mostly occurs in the upper aerodigestive tracts. Basaloid squamous cell carcinoma also typically arises in the anal canal, but is extremely rare in the lower gastrointestinal tract. A 70-year-old man presented with loose stool and intermittent hematochezia 2 months ago. Colonoscopy showed an ulceroinfiltrative mass on the rectosigmoid colon from 16 cm to 18 cm above the anal verge. Conventional colonoscope could not pass through the lesion but it was possible with pediatric colonoscope. Abdominal CT scan showed 1.6 cm sized wall thickening with circumferential luminal narrowing in the rectosigmoid colon and multiple ill-defined low density masses in both lobes of the liver. Therefore, colon cancer with liver metastasis was suspected. However, basaloid cells were noted on histologic examination, and they were weakly positive for synaptophysin on immunohistochemical study. After palliative lower anterior resection, histologic examination of the resected specimen revealed basaloid differentiation with keratin pearls, and tumor cells were positively stained with high molecular weighted cytokeratin (34BE12) and CK 5/6. Thus, the patient was finally diagnosed with basaloid squamous cell carcinoma of rectosigmoid colon with distant metastases.
Aged ; Carcinoma, Squamous Cell/*diagnosis/pathology/surgery ; Colonoscopy ; Colorectal Neoplasms/*diagnosis/pathology/surgery ; Humans ; Immunohistochemistry ; Keratins/metabolism ; Liver Neoplasms/radiography/secondary ; Lung Neoplasms/radionuclide imaging/secondary ; Male ; Positron-Emission Tomography ; Synaptophysin/metabolism ; Tomography, X-Ray Computed

No abstract available.
Bone Marrow Cells/pathology ; Bone and Bones/radionuclide imaging ; Female ; Humans ; Lung Neoplasms/diagnosis/radiography ; Middle Aged ; Multimodal Imaging ; Multiple Myeloma/*diagnosis/pathology/radiography ; Tomography, X-Ray Computed

Pulmonary paragonimiasis is a relatively rare cause of lung disease revealing a wide variety of radiologic findings, such as air-space consolidation, nodules, and cysts. We describe here a case of pulmonary paragonimiasis in a 27-year-old woman who presented with a 2-month history of cough and sputum. Based on chest computed tomography (CT) scans and fluorodeoxyglucose positron emission tomography (FDG-PET) findings, the patient was suspected to have a metastatic lung tumor. However, she was diagnosed as having Paragonimus westermani infection by an immunoserological examination using ELISA. Follow-up chest X-ray and CT scans after chemotherapy with praziquantel showed an obvious improvement. There have been several reported cases of pulmonary paragonimiasis mimicking lung tumors on FDG-PET. However, all of them were suspected as primary lung tumors. To our knowledge, this patient represents the first case of paragonimiasis mimicking metastatic lung disease on FDG-PET CT imaging.
Adult ; Animals ; Diagnostic Errors ; Female ; Humans ; Lung Diseases, Parasitic/*diagnosis/*parasitology/radiography/radionuclide imaging ; Lung Neoplasms/*diagnosis ; Paragonimiasis/*diagnosis/*parasitology/radiography/radionuclide imaging ; Paragonimus westermani/isolation & purification ; Positron-Emission Tomography ; Tomography, X-Ray Computed

OBJECTIVE: Lymphomatoid granulomatosis (LG) is a rare, aggressive extranodal Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disease. The purpose of our study was to analyze the CT and fluorodeoxyglucose positron emission tomography (FDG-PET) findings of pulmonary LG. MATERIALS AND METHODS: Between 2000 and 2009, four patients with pathologically proven pulmonary LG and chest CT were identified. Two of these patients also had FDG-PET. Imaging features of LG on CT and PET were reviewed. RESULTS: Pulmonary nodules or masses with peribronchovascular, subpleural, and lower lung zonal preponderance were present in all patients. Central low attenuation (4 of 4 patients), ground-glass halo (3 of 4 patients), and peripheral enhancement (4 of 4 patients) were observed in these nodules and masses. An air-bronchogram and cavitation were seen in three of four patients. FDG-PET scans demonstrated avid FDG uptake in the pulmonary nodules and masses. CONCLUSION: Pulmonary LG presents with nodules and masses with a lymphatic distribution, as would be expected for a lymphoproliferative disease. However, central low attenuation, ground-glass halo and peripheral enhancement of the nodules/masses are likely related to the angioinvasive nature of this disease. Peripheral enhancement and ground-glass halo, in particular, are valuable characteristic not previously reported that can help radiologists suggest the diagnosis of pulmonary LG.
Adult ; Biopsy, Needle ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Lung Neoplasms/pathology/*radiography/*radionuclide imaging ; Lymphomatoid Granulomatosis/pathology/*radiography/*radionuclide imaging ; Male ; Middle Aged ; *Positron-Emission Tomography ; Radiopharmaceuticals/*diagnostic use ; *Tomography, X-Ray Computed

BACKGROUND/AIMS: Although carcinoid tumors usually have good prognosis, early and specific diagnosis is important. Computed tomography and magnetic resonance imaging do not provide findings that are specific for carcinoids, and somatostatin receptor scintigraphy suffers from low spatial resolution. 18-Fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has limited sensitivity for carcinoids due to low uptake of the marker. A PET/CT system that uses the somatostatin receptor-based PET tracer 1,4,7,10-tetraazacyclododecane-N(I),N(II),N(III),N(IIII)-tetraacetic acid (D)-Phe(1)-thy(3)-octreotide ((68)Ga-DOTATOC) has also been used in the evaluation of carcinoids, although information regarding its use for the detection of primary pulmonary carcinoids is limited. Thus, we investigated the value of (68)Ga-DOTATOC PET/CT for the diagnosis of primary pulmonary carcinoid tumors. METHODS: This was a retrospective analysis of patients with primary pulmonary tumors who underwent (68)Ga-DOTATOC PET/CT. All the patients had a histopathologic diagnosis of carcinoid. The rate of detection of primary pulmonary carcinoid tumors using (68)Ga-DOTATOC PET/CT was assessed. RESULTS: Twenty patients were diagnosed as having carcinoid, and 19 tumors showed significant uptake on (68)Ga-DOTATOC (detection rate, 95%). The maximal standardized uptake value (SUV(max)) ranged from 1.1 to 66, with a median value of 21.6. In one patient, (68)Ga-DOTATOC PET/CT revealed additional lesions. CONCLUSIONS: Our results demonstrate that (68)Ga-DOTATOC PET/CT is useful in the evaluation of primary pulmonary carcinoids and should be included in the diagnostic work-up of these patients.
Adolescent ; Adult ; Carcinoid Tumor/*diagnosis/radiography/radionuclide imaging ; Female ; Gallium Radioisotopes/*diagnostic use ; Humans ; Lung Neoplasms/*diagnosis/radiography/radionuclide imaging ; Male ; Middle Aged ; Octreotide/*analogs & derivatives/diagnostic use ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/*diagnostic use ; Retrospective Studies ; Tomography, X-Ray Computed/*methods

OBJECTIVE: We aimed to review the patterns of lung abnormalities of pulmonary cryptococcosis on CT images, position emission tomography (PET) findings of the disease, and the response of lung abnormalities to the therapies in non-AIDS patients. MATERIALS AND METHODS: We evaluated the initial CT (n = 23) and 18F-fluorodeoxyglucose (FDG) PET (n = 10), and follow-up (n = 23) imaging findings of pulmonary cryptococcosis in 23 non-AIDS patients. Lung lesions were classified into five patterns at CT: single nodular, multiple clustered nodular, multiple scattered nodular, mass-like, and bronchopneumonic patterns. The CT pattern analyses, PET findings, and therapeutic responses were recorded. RESULTS: A clustered nodular pattern was the most prevalent and was observed in 10 (43%) patients. This pattern was followed by solitary pulmonary nodular (n = 4, 17%), scattered nodular (n = 3, 13%), bronchopneumonic (n = 2, 9%), and single mass (n = 1, 4%) patterns. On PET scans, six (60%) of 10 patients showed higher FDG uptake and four (40%) demonstrated lower FDG uptake than the mediastinal blood pool. With specific treatment of the disease, a complete clearance of lung abnormalities was noted in 15 patients, whereas a partial response was noted in seven patients. In one patient where treatment was not performed, the disease showed progression. CONCLUSION: Pulmonary cryptococcosis most commonly appears as clustered nodules and is a slowly progressive and slowly resolving pulmonary infection. In two-thirds of patients, lung lesions show high FDG uptake, thus simulating a possible malignant condition.
Adult ; Aged ; Contrast Media/diagnostic use ; Cryptococcosis/*radiography/*radionuclide imaging/therapy ; Disease Progression ; Female ; Fluorodeoxyglucose F18/diagnostic use ; Follow-Up Studies ; Humans ; Lung Diseases, Fungal/*radiography/*radionuclide imaging/therapy ; Male ; Middle Aged ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/diagnostic use ; Retrospective Studies ; Tomography, Spiral Computed/*methods

Primary pulmonary T-cell lymphoma is an extremely rare malady, and we diagnosed this in a 52-year-old male who was admitted to our hospital with cough for the previous two weeks. The chest CT demonstrated multiple variable sized mass-like consolidations with low density central necrosis in the peripheral portion of both the upper and lower lobes. Positron emission tomography (PET) showed multiple areas of hypermetabolic fluorodeoxyglucose (FDG) uptake in both lungs with central metabolic defects, which correlated with central necrosis seen on CT. The histological sample showed peripheral T-cell lymphoma of the not otherwise specified form. The follow-up CT scan showed an increased extent of the multifocal consolidative lesions despite that the patient had undergone chemotherapy.
Contrast Media/diagnostic use ; Cough/etiology ; Diagnosis, Differential ; Fatal Outcome ; Fever/etiology ; Fluorodeoxyglucose F18/diagnostic use ; Follow-Up Studies ; Humans ; Lung/radiography/radionuclide imaging ; Lung Neoplasms/complications/*radiography/*radionuclide imaging ; Lymphoma, T-Cell/complications/*radiography/*radionuclide imaging ; Male ; Middle Aged ; Pneumonia/complications ; Positron-Emission Tomography/methods ; Radiographic Image Enhancement/methods ; Sweating ; Tomography, X-Ray Computed/methods

OBJECTIVE: The aim of this study was to assess the diagnostic efficacy of integrated PET/CT using fluorodeoxyglucose (FDG) for the differentiation of benign and metastatic adrenal gland lesions in patients with lung cancer and to compare the diagnostic efficacy with the use of PET alone. MATERIALS AND METHODS: Sixty-one adrenal lesions (size range, 5-104 mm; mean size, 16 mm) were evaluated retrospectively in 42 lung cancer patients. Both PET images alone and integrated PET/CT images were assessed, respectively, at two-month intervals. PET findings were interpreted as positive if the FDG uptake of adrenal lesions was greater than or equal to that of the liver, and the PET/CT findings were interpreted as positive if an adrenal lesion show attenuation > 10 HU and showed increased FDG uptake. Final diagnoses of adrenal gland lesions were made at clinical follow-up (n = 52) or by a biopsy (n = 9) when available. The diagnostic accuracies of PET and PET/CT for the characterization of adrenal lesions were compared using the McNemar test. RESULTS: Thirty-five (57%) of the 61 adrenal lesions were metastatic and the remaining 26 lesions were benign. For the depiction of adrenal gland metastasis, the sensitivity, specificity, and accuracy of PET were 74%, 73%, and 74%, respectively, whereas those of integrated PET/CT were 80%, 89%, and 84%, respectively (p values; 0.5, 0.125, and 0.031, respectively). CONCLUSION: The use of integrated PET/CT is more accurate than the use of PET alone for differentiating benign and metastatic adrenal gland lesions in lung cancer patients.
Adrenal Gland Neoplasms/pathology/*radiography/*radionuclide imaging/secondary ; Adult ; Aged ; Biopsy ; Diagnosis, Differential ; Female ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Lung Neoplasms/pathology/*radiography/*radionuclide imaging ; Male ; Middle Aged ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/*diagnostic use ; Retrospective Studies ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods