Incidental diagnosis of tumor thrombosis on FDG PET/CT imaging

Value of 18F-FDG PET/CT Combined with Lung HRCT in Diagnosis of Solitary Pulmonary Intravascular Metastasis

Background

Solitary pulmonary intravascular metastasis is a rare complication of malignant tumors, and accurate diagnosis can improve clinical decision-making, but diagnosing it effectively using conventional techniques is difficult.

Purpose

To explore the value of ¹⁸F-FDG PET/CT combined with lung high-resolution computed tomography (HRCT) in the diagnosis of solitary pulmonary intravascular metastasis.

Methods

¹⁸F-FDG PET/CT, lung HRCT, and follow-up data of 18,143 cancer patients were retrospectively analyzed to select patients with pulmonary vessel involvement besides the primary tumor only. The histopathological or imaging follow-up results were used as the diagnostic criteria for pulmonary intravascular metastasis.

Results

A total of 13 patients with 17 pulmonary intravascular metastases were found, of which 9 patients had a single lesion and 4 had double. The SUVmax was 1.1–5.4 (average, 2.4 ± 1.4), and the length of hypermetabolic metastasis was 5.1–24.1 mm (average, 10.7 ± 6.5 mm). All the intravascular metastases were located in the terminal pulmonary vessels. Strip or branched pulmonary vessels enlargement with increased metabolism was the main imaging manifestation (15/17, 88.2%), while the other 2 cases only showed strip metabolic enhancement without abnormalities in pulmonary vessels (2/17, 11.8%). Four pulmonary intravascular metastases were confirmed by pathology, and the other 13 cases were diagnosed by imaging follow-up.

Conclusion

¹⁸F-FDG PET/CT combined with lung HRCT is an effective technique for the diagnosis of solitary pulmonary intravascular metastasis. High-strip or branched FDG uptake in the distal pulmonary vessel accompanied by corresponding morphological changes in patients with malignant tumors can be used as a specific diagnostic indicator.

Primary Parotid Tumor Thrombosis: Immunohistologic Features and Awareness of Metastatic Potential

Tumor thrombosis is a poor prognostic feature and an exceptionally rare occurrence in salivary gland malignancies. We present a case of primary parotid myoepithelial carcinoma (MC) with tumor thrombosis in the external jugular vein (EJV). An 82-year-old man presented with a right-sided facial mass. MRI with and without gadolinium demonstrated a mass of the right parotid gland with a filling defect of the right EJV. The patient underwent right parotidectomy and selective neck dissection. Tumor thrombosis was found intraoperatively within the EJV. Final pathology demonstrated a poorly differentiated MC. Adjuvant radiation therapy without concurrent systemic therapy was administered. Three months later, restaging positron emission tomography (PET) with CT revealed numerous bilateral pulmonary nodules with biopsy, demonstrating poorly differentiated MC without locoregional relapse. Given that primary parotid tumor thrombosis is associated with a poor prognosis, the use of early systemic therapy should be investigated.

The Diagnostic Value of FDG PET/CT and Thin-Slice High-Resolution Chest CT in Pulmonary Intravascular Metastasis

OBJECTIVE. Pulmonary intravascular metastasis is a special type of pulmonary metastasis of malignancies; however, few relevant studies have been performed. This study aimed to determine the characteristics of pulmonary intravascular metastasis and improve understanding of the disease by retrospective analysis of FDG PET/CT and thin-layer high-resolution CT (HRCT) imaging of the chest in patients with tumors. MATERIALS AND METHODS. We identified all patients who underwent FDG PET/CT at two hospitals between January 2016 and February 2019 and conducted a comparative analysis of HRCT and PET/CT images. In total, 84 patients (38 women and 46 men) ranging in age from 35 to 82 years old (mean age, 54.7 ± 14.5 [SD] years) participated in the study. Patient characteristics were summarized, and diagnosis was confirmed by chest CT or PET/CT follow-up. RESULTS. A total of 260 pulmonary intravascular metastases were found, which were classified as type I (no significant abnormality, n = 5), type II (abrupt and uneven thickening of the pulmonary vessel, n = 118), type III (simultaneous invasion of adjacent pulmonary vessel, n = 121), and type IV (large strip-shaped high-density mass, n = 16). The majority were located in peripheral pulmonary vessels (94.2% [245/260]). FDG up-take was increased in 252 lesions, and the mean SUV_max was 4.6 ± 2.5. CONCLUSION. The combination of PET/CT and chest HRCT is an effective approach for detecting pulmonary intravascular metastasis. The linear pattern of FDG uptake, abnormal pulmonary blood vessel morphology, and location (below the lung segment) are specific indicators for the diagnosis of pulmonary intravascular metastasis and should be recognized by clinicians and radiologists.

Rare case of venous tumour thrombus from acinic cell carcinoma of the parotid gland

Head and neck tumour thrombus is a rare pathology and at present there are no reported cases of tumour thrombus secondary to acinic cell carcinoma of the parotid gland. We report a case of an 81-year-old man with an acinic cell carcinoma of the left parotid and an intravenous tumour thrombus extending from the retromandibular vein into the internal jugular vein. This case also highlights the importance of radiological imaging in the management of tumour thrombus.

Diagnosis of Deep Venous Thrombosis and Pulmonary Embolism: New Imaging Tools and Modalities

Imaging continues to be the modality of choice for the diagnosis of venous thromboembolic disease, particularly when incorporated into diagnostic algorithms. Improvement in imaging techniques as well as new imaging modalities and processing methods have improved diagnostic accuracy and additionally are being leveraged in prognostication and decision making for choice of intervention. In this article, we review the role of imaging in diagnosis and prognostication of venous thromboembolism. We also discuss emerging imaging approaches that may in the near future find clinical usefulness in improving diagnosis and prognostication as well as differentiating disease phenotypes.

[Clinically relevant incidental cardiovascular findings in CT examinations]

BACKGROUND AND METHOD

Incidental cardiovascular findings are a frequent phenomenon in computed tomography (CT) examinations. As the result of a dedicated PubMed search this article gives a systemic overview of the current literature on the most important incidental cardiovascular findings, their prevalence and clinical relevance.

RESULTS

The majority of incidental cardiovascular findings are of only low clinical relevance; however, highly relevant incidental findings, such as aortic aneurysms, thromboses and thromboembolic events can also occasionally be found, especially in oncology patients.

CONCLUSION

The scans from every CT examination should also be investigated for incidental findings as they can be of decisive importance for the further clinical management of patients, depending on their clinical relevance.

Venous thrombosis of sarcoidosis as an unusual incidental finding on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

Sarcoidosis is defined as a multisystem granulomatous disorder of unknown cause. Venous thrombosis (VT) in the sarcoidosis is rare. The routine use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has resulted in clinicians detecting many incidental findings, which have proven to be clinically significant such as thrombosis. Here, we present a case with VT of sarcoidosis in the inferior vena cava and portal vein as an unusual incidental finding on 18F-FDG PET/CT.