Diagnostic Performance of 18 F-FDG Positron Emission Tomography/Computed Tomography and Blood Test Parameters for Pulmonary Inflammatory Pseudotumor.

PURPOSE: Pulmonary inflammatory pseudotumor (PIP) is an inflammatory proliferative tumor-like lesion that frequently exhibits hypermetabolism on 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography imaging (PET/CT) and is readily misdiagnosed as a malignant tumor. The purpose of this study was to identify PIP by combining PET/computed tomography metabolic and blood test characteristics with machine learning. PATIENTS AND METHODS: We recruited 27 patients with PIP and 28 patients with lung cancer (LC). The PET metabolic and blood test parameters were collected, and the differences between the groups were evaluated. In addition, we combined the support vector machine (SVM) classifier with the indicators that differed between the groups to classify PIP and LC. RESULTS: For PET metabolic parameters, our findings showed that, as compared with the LC group, maximal standardized uptake value ( P < 0.001, t = -4.780), Mean standardized uptake value SUV mean , P < 0.001, t = -4.946), and SD40% ( P < 0.001, t = -4.893) were considerably reduced in the PIP group, whereas CV40% ( P = 0.004, t = 3.012) was significantly greater. For blood test parameters, the total white blood cell count ( P < 0.001, t = 6.457) and absolute neutrophil count ( P < 0.001, t = 6.992) were substantially higher in the PIP group than in the LC group. Furthermore, the performance of SVM trained solely on PET metabolic parameters (mean area under the curve [AUC] = 0.84) was comparable to that of SVM trained solely on blood test parameters (mean AUC = 0.86). Surprisingly, utilizing the combined parameters increased SVM performance significantly (mean AUC = 0.98). CONCLUSION: PET metabolic and blood test parameters differed significantly between the PIP and LC groups, and the SVM paradigm using these significantly different features has the potential to be used to classify PIP and LC, which has important clinical implications.

Syphilitic Pulmonary Inflammatory Pseudotumor: A Diagnostic Challenge.

A 46-year-old man presented with nonproductive cough and lower limb swelling. Chest radiograph showed a left lower lobe lung mass and multiple subpleural nodules. Other investigations revealed that he had nephrotic syndrome. Core biopsies of the left lower lobe lung mass showed features of inflammatory pseudotumor with endarteritis obliterans and a lymphoplasmacytic infiltrate. Immunohistochemical stain for Treponema pallidum was positive. Resolution of the lung mass and nephrotic syndrome was achieved after treatment with intramuscular benzathine benzylpenicillin. The differential diagnosis of pulmonary inflammatory pseudotumor, manifestations of pulmonary syphilis, and a literature review of secondary syphilis of the lung are discussed.

[The diagnostic value of FDG coincidence imaging combined with serum tumor marker assays for pulmonary lesions].

OBJECTIVE: To evaluate the performance of 18F-FDG three-head tomography with coincidence imaging and serum tumor marker assays in identifying lung lesions in 104 patients with abnormal findings on chest X-ray or computer tomography. METHODS: A prospective evaluation of 18F-FDG coincidence imaging and the measurement of 3 serum markers for lung cancer ( carcinoembryonic antigen, CYFRA21-1 and neuron specific enolase) were performed within one week in 104 inpatients with suspected lung malignancy. All images were analyzed visually. It was considered positive for malignancy if the 18F-FDG uptake was increased relative to that in the adjacent lung tissue, and was focal. The serum tumor marker test was considered positive for malignancy if the serum level of at least one marker was elevated. RESULTS: 66 patients were proven to have lung cancer by pathology, and 38 patients had benign lung diseases. The sensitivity, specificity, accuracy of 18F-FDG coincidence imaging and serum tumor markers in assessing lung cancers were 80. 0% , 77. 2% , 77. 9% and 56. 0% , 60. 9%, 64. 4% , respectively. 18F-FDG coincidence images in assessing lung lesions showed significantly higher sensitivity, specificity and accuracy than serum tumor markers. Four patients with lung cancer had negative findings on 18F-FDG coincidence images but showed positive serum markers. CONCLUSION: 18F-FDG coincidence imaging is a powerful tool for evaluating patients with lung lesions suggestive of malignancy. Although the determination of serum marker levels is less accurate than 18F-FDG coincidence imaging, the combination of a positive 18F-FDG coincidence result and positive tumor markers may be helpful in improving the diagnosis of lung cancers.

Pulmonary inflammatory pseudotumor with rapid growth and serum carcinoembryonic antigen elevation.

Inflammatory pseudotumors consist of chronic inflammatory cells, predominantly plasma cells. We report a rare case of pulmonary inflammatory pseudotumor associated with rapid growth and elevated serum carcinoembryonic antigen (CEA). A 75-year-old man referred for bloody sputum was found in chest computed tomography (CT) to have a round circumscribed tumor with a cavity located in the periphery of the right lower pulmonary lobe. Cytological examination of a biopsy specimen obtained by CT-guided transthoracic fine needle aspiration showed no malignancy. Two months later, the tumor had noticeably grown, accompanied by a notable rise in serum CEA. We conducted right lower pulmonary lobectomy with regional lymph node dissection, since malignancy could not be ruled out by frozen-section examination. Histological examination of the resected specimen showed an inflammatory pseudotumor with CEA production.