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

Thoracic splenosis is an autotransplantation of splenic tissue to thorax resulting from splenic and diaphragmatic injury. Thoracic splenosis is usually discovered incidentally on routine thoracic imaging as single or multiple left-sided pleural-based masses without symptoms. Traditionally, patients often undergo an invasive diagnostic procedures including thoracotomy to acquire tissue samples in order to exclude other causes of lung mass. The combination of imaging findings and clinical history make it avoid unnecessary invasive diagnostic procedure to confirm. Therefore, thoracic splenosis should be considered in the differential diagnosis of asymptomatic patients with multiple, left-sided pleural-based nodules and previous history of thoracoabdominal injury and splenectomy. Here we report a case of thoracic splenosis diagnosed without invasive procedure.
Autografts ; Diagnosis* ; Diagnosis, Differential ; Humans ; Lung ; Radionuclide Imaging ; Splenectomy ; Splenosis* ; Thoracotomy ; Thorax

Extramedullary pulmonary hematopoiesis is a rare entity with a limited number of case reports in the available literature only. We report the case of a 66-year-old man with known primary myelofibrosis, in whom a Technetium-99m sulfur colloid bone marrow scan with single-photon emission computed tomography (SPECT)/CT revealed a pulmonary hematopoiesis as the cause of pulmonary hypertension and severe tricuspid regurgitation. To the best of our knowledge, this is the first description of Technetium-99m sulfur colloid SPECT/CT imaging in this rare condition.
Aged ; Bone Marrow/*radionuclide imaging ; *Hematopoiesis, Extramedullary ; Humans ; Hypertension, Pulmonary/*etiology/radionuclide imaging ; Lung/*radionuclide imaging ; Male ; Primary Myelofibrosis/complications ; Technetium Tc 99m Sulfur Colloid/diagnostic use ; Tomography, Emission-Computed, Single-Photon/methods ; Tomography, X-Ray Computed ; Tricuspid Valve Insufficiency/*etiology/radionuclide imaging

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

The radiologic appearance of multiple discrete pulmonary nodules in immunocompetent patients, with cryptococcal infection, has been rarely described. We describe a case of pulmonary cryptococcosis, presenting with bilaterally and randomly distributed nodules on a computed tomography, mimicking hematogeneous metastases. Positron emission tomography does not demonstrate 18F-fluorodeoxyglucose (FDG) uptake, suggesting a low probability for malignancy, which is a crucial piece of information for clinicians when making a management decision. We find the absence of FDG uptake correlates with the pathologic finding of an infectious nodule, composed of fibrosis and necrosis.
Cryptococcosis/metabolism/*radionuclide imaging ; Fluorodeoxyglucose F18/*diagnostic use/pharmacokinetics ; Humans ; Immunocompetence ; Lung Diseases, Fungal/metabolism/*radionuclide imaging ; Lung Neoplasms/radionuclide imaging ; Male ; Middle Aged ; Multimodal Imaging/*methods ; Multiple Pulmonary Nodules/radionuclide imaging ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/*diagnostic use/pharmacokinetics ; Tomography, X-Ray Computed/*methods

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

Extra marginal-zone lymphomas of the lung is a very rare tumor and it originates from bronchial-associated lymphoid tissue. A 68-yr-old woman presented with productive cough and dyspnea. A thorax computed tomography scan showed a 9 x 10 cm in size mass in the left lung and pleural effusion in the lower lobe of left lung. Positron emission tomography/computed tomography (PET/CT) revealed intense uptake foci at the upper and middle sites of left lung and slight uptake foci at the mediastinal lymph nodes which showed malignant involvement. After bronchoscopic biopsy, the diagnosis of pulmonary bronchial-associated lymphoid tissue (BALT) lymphoma was confirmed. At the end of the eight cycles weekly rituximab treatment, complete response was obtained by PET/CT findings. It is concluded that extended rituximab schedule is more effective and it would be beneficial to investigate the use of PET/CT in the diagnosis and evaluating of the treatment response of pulmonary BALT lymphoma.
Aged ; Antibodies, Monoclonal, Murine-Derived/*administration & dosage ; Antineoplastic Agents/*administration & dosage ; Drug Administration Schedule ; Female ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Lung Neoplasms/*drug therapy/pathology/radionuclide imaging ; Lymphoma, B-Cell, Marginal Zone/*drug therapy/pathology/radionuclide imaging ; Positron-Emission Tomography ; Radiopharmaceuticals/*diagnostic use ; 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

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