False-negative real-time polymerase chain reaction tests in COVID-19 patients: an epidemiological analysis of 302 patients.

OBJECTIVES: Patients who arrive at the emergency department (ED) with COVID-19, who test negative at the first real-time polymerase chain reaction (RT-PCR), represent a clinical challenge. This study aimed to evaluate if the clinical manifestation at presentation, the laboratory and imaging results, and the prognosis of COVID-19 differ in patients who tested negative at the first RT-PCR compared with those who tested positive and also to evaluate if comorbid conditions patient-related or the period of arrival are associated with negative testing. STUDY DESIGN: We retrospectively collected clinical data of patients who accessed the ED from March 1 to May 15, 2020. METHODS: We compared clinical variables, comorbid conditions, and clinical outcomes in the two groups by univariate analysis and logistic regression. RESULTS: Patients who tested negative at the first RT-PCR showed a higher prevalence of cardiopathy, immunosuppression, and diabetes, as well as a higher leukocyte and lower lymphocyte counts compared with patients who tested positive. A bilateral interstitial syndrome and a typical pattern at computed tomography scan were prevalent in the test-negative group. Test-negative patients were more likely to be admitted to the hospital but less likely to need admission in a high level of care ward. The false-negative rate increased from March to May. CONCLUSION: False-negative RT-PCR COVID-19 patients present a similar spectrum of symptoms compared with positive cohort, but more comorbidities. Imaging helps to identify them. True positives had a higher risk of serious complications.

May an adrenal incidentaloma change its nature?

BACKGROUND: Up to 70% of adrenal masses detected in patients affected by extra-adrenal malignancy are metastatic lesions. Therefore, detection of an adrenal mass in patients with active or previous malignancy requires a careful differential diagnostic workup. 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is increasingly being used to determine the malignant potential of adrenal lesions. CLINICAL CASE: We report the case of a 64-year-old man who had a single adrenal metastasis due to non-small-cell lung carcinoma developing on a pre-existing benign adrenal lesion. This metastasis occurred in a phase of perceived oncological remission and was detected thanks to 18F-FDG-PET/CT showing a focal adrenal uptake. Contrast-enhanced computed tomography (CT), performed as part of oncological follow-up, and MRI with chemical shift sequences did not lead to the correct diagnosis. The patient underwent laparoscopic adrenalectomy and the pathological evaluation confirmed a lung carcinoma metastasis. CONCLUSION: The present case highlights the peculiarity of the follow-up of adrenal masses in cancer patients and the primary role of 18F-FDG-PET/CT in the management of such patients.

Long-term outcome of radiofrequency thermal ablation (RFA) of liver metastases from colorectal cancer (CRC): size as the leading prognostic factor for survival.

PURPOSE: The aim of this study was to review some prognostic factors for survival after radiofrequency ablation (RFA) of metastases from colorectal cancer (CRC). MATERIALS AND METHODS: From 1996 to 2009, 262 patients with metastases from CRC were treated with RFA. Fourteen were lost to follow-up. The following predictors were analysed in the remaining 248: synchronous/metachronous metastases, single/multiple metastases, diameter of largest metastasis and absence/presence of extrahepatic metastases. Survival was measured from the date of metastasis diagnosis and from the date of RFA. RESULTS: Survival at 1, 2, 3 and 5 years was 93%, 78%, 62% and 35% from metastasis diagnosis, and 84%, 59%, 43% and 23% from the date of RFA. Median survival was 41 months in patients with largest metastasis ≤3 cm and 21.7 months for those with metastases >3 cm (p=0.0001); survival increased to 45.2 months in patients with largest metastasis ≤2.5 cm and fell to 18.5 months in those with metastasis >3.5 cm. Median survival of patients with extrahepatic metastases was significantly lower than that of patients without extrahepatic disease (23.3 vs. 32.6 months, p=0.018). CONCLUSIONS: In light of our long-term results obtained with commonly used equipment, small lesion size (diameter of largest lesion ≤3 or 2.5 cm) proved to be the most favourable prognostic factor for survival in patients with CRC metastases to the liver treated with RFA. This conclusion is probably related to the possibility of obtaining radical ablation and points to the usefulness of devices allowing ablation of larger volumes. In the presence of extrahepatic metastases, RFA has less impact on survival, even though it is potentially useful in patients at a higher risk of death due to hepatic rather than extrahepatic metastases.

The pulmonary nodule: clinical and radiological characteristics affecting a diagnosis of malignancy.

The role of computed tomography (CT) in the diagnosis of the solitary pulmonary nodule (SPN) is constantly expanding. CT helps to detect a growing number of increasingly small lesions, but, as with chest radiography, the primary goal in the evaluation of small pulmonary nodules is to exclude malignancy. Despite the availability of numerous, variously invasive, diagnostic tests, diagnostic accuracy tends to decline as the size of the nodule decreases. The role of the radiologist is therefore to help the clinician determine the most appropriate management strategy by using all available modalities [CT, magnetic resonance (MR) imaging, positron emission tomography (PET)] and evaluating the patient's clinical history and the imaging features leading to a diagnosis of benignity or malignancy. Imaging features include nodule size, margins, calcifications and fatty component, internal features (cavitations, pseudocavitations, air bronchogram, halo sign), as well as advanced techniques for characterisation (growth rate, contrast enhancement) and management (computer-aided diagnosis, Bayesian analysis, neural networks). The aim of this paper is to summarise the approach to pulmonary nodules from the point of view of the radiologist, oncologist and thoracic surgeon.

Solitary fibrous tumor of the lung: three rare cases of intraparenchymal nodules.

Solitary fibrous tumor (SFT) of the pleura usually presents as a peripheral mass, in contact with the surface of the pleura. However, on occasion, it can occur separately from the pleura, in the lung parenchyma. We describe the radiological and imaging features of three SFTs of the lung, diagnosed in our department, with relevant clinical data. The diagnosis of SFT of the lung, although rare, should be considered in a slow-growing solitary lung parenchymal nodule.

Fibrous tumour of the pleura (SFTP): a proteiform disease. Clinical, histological and atypical radiological patterns selected among our cases.

First described by Klemperer and Rabin in 1931, solitary fibrous tumour of the pleura (SFTP) is a mesenchymal tumour that tends to involve the pleura, although it has also been described in other thoracic areas (mediastinum, pericardium and pulmonary parenchyma) and in extrathoracic sites (meninges, epiglottis, salivary glands, thyroid, kidneys and breast). SFTP usually presents as a peripheral mass abutting the pleural surface, to which it is attached by a broad base or, more frequently, by a pedicle that allows it to be mobile within the pleural cavity. A precise preoperative diagnosis can be arrived at with a cutting-needle biopsy, although most cases are diagnosed with postoperative histology and immunohistochemical analysis of the dissected sample. SFTP, owing to its large size or unusual locations (paraspinal, para-mediastinal, intra-fissural and intraparenchymal), can pose interpretation problems or, indeed, point towards a diagnosis of diseases of a totally different nature. We present some unusual radiographic and computed tomography (CT) images of large SFTP or SFTP located in atypical thoracic locations in patients who underwent surgical resection.

Bronchogenic cysts in the adult: diagnostic criteria derived from the correct use of standard radiography and computed tomography.

PURPOSE: This study was undertaken to identify the radiographic and computed tomography patterns allowing a diagnosis of bronchogenic cyst. MATERIALS AND METHODS: We retrospectively reviewed chest radiographs and CT scans of 21 adults (ten men and 11 women, age range 18-74 years) with a histologically confirmed diagnosis of bronchogenic cyst. RESULTS: Sixteen cysts were located in the mediastinum and five in the lungs. On chest radiography, mediastinal cysts appeared as sharply marginated rounded areas of increased opacity; intrapulmonary cysts also exhibited an air-fluid interface. CT confirmed these morphological features in all cases. In addition, analysis of attenuation values allowed the subdivision of mediastinal cysts into three groups: fluid density (four cases), air density (two cases) and soft-tissue density (ten cases). CONCLUSIONS: All bronchogenic cysts were visualised on chest radiography, but the findings were nonspecific and required further characterisation by CT. The CT findings proved to be diagnostic when cystic attenuation values were evident. When soft-tissue attenuation values were demonstrated, a confident diagnosis was not possible, and other solid lesions had to be considered. In such cases, magnetic resonance imaging may be helpful to ascertain the cystic nature of the lesions.

CT features of solitary fibrous tumour of the pleura: experience in 26 patients.

PURPOSE: The purpose of this study was to identify the typical computed tomography (CT) features of solitary fibrous tumours of the pleura (SFTP) and determine which findings would allow confirmation of the pleural origin or benign behaviour of the tumour. MATERIALS AND METHODS: Twenty-six preoperative CT studies of the chest (23 enhanced and 14 unenhanced) were retrospectively reviewed. RESULTS: Up to 50% of SFTP were larger than 10 cm. At unenhanced CT, they showed homogeneous attenuation in 5 cases (35.7%) and inhomogeneous attenuation in 9 (64.3%). At contrast-enhanced CT, they were inhomogeneous in 21 cases (91.3%), with geographic pattern (61.9% of cases), serpiginous linear areas of enhancement (intralesional vessels) (23.8%), rounded (52.4%) or linear (33.3%) areas of low attenuation (necrosis). CONCLUSIONS: Depending on location, size and histological features, SFTP may produce a large spectrum of findings. Typical CT features of small SFTP were well-defined margins and smooth contours, homogeneous attenuation and right or obtuse angles with the pleura. Larger lesions were characterised by well-defined margins and lobulated contours, geographic pattern in enhanced CT scans, acute angles or smooth tapering margins with the pleura.