Adrenal incidentalomas, defined as masses discovered incidentally during imaging investigation of non-adrenal disorders, have become a rather common finding in clinical practice. The prevalence is not well characterized and varies among studies. The aim of the present study was to perform a prospective evaluation of the prevalence of adrenal incidentalomas among subjects undergoing computerized tomography (CT) scan of the chest in a screening program of lung cancer (Tic TAC study) in Piedmont, a region of Northwestern Italy. This evaluation included 520 subjects (382 males and 138 females, aged between 55-82 yr), referred to our hospital from April to December 2001. Twenty-three patients with adrenal masses were identified: 21 adrenal adenomas, 1 myelolipoma, and 1 metastasis of lung cancer. Therefore, the overall prevalence of adrenal lesions was 4.4%, and that of benign adrenal masses was 4.2%. This prevalence is higher than those found in previous CT scan series reported in the literature, probably because of the use of high-resolution CT scanning technology. Another factor that influenced our results is that subject age is skewed towards the decades characterized by a greater occurrence of adrenal masses. The outcome of this study confirms that we are presently able to identify incidentally discovered adrenal masses more often than in early years and that the prevalence of adrenal incidentalomas on CT images is approaching that of autopsy series. The present study provides a reliable estimate of the prevalence of adrenal incidentaloma with currently used CT scanners. Notwithstanding that our subjects were at increased risk of lung cancer, the rate of adrenal metastases was low. We think that the present results can be generalized even if we may disclose the lack of histological diagnosis.

Mediastinal tumours are frequently asymptomatic and first noted on routine chest radiograph. In most cases, evaluation should proceed to spiral computed tomography (sCT) of the chest with iodinated contrast material. The specific location and appearance of tumours on sCT is instrumental in planning further diagnostic and treatment strategies. Primary tumours in the anterior mediastinum account for half of all mediastinal masses. They comprise various benign and malignant neoplasms, but a wide variety of nonneoplastic lesions (developmental, inflammatory) can present as a localised mass in this compartment. The most common primary anterior mediastinal tumours are thymoma, teratoma and lymphoma; all other lesions are rare. Nonneoplastic conditions include thymic cysts, lymphangioma and intrathoracic goitre. Understanding the pathology, clinical presentation, imaging and diagnosis of the major tumour types is instrumental in the safe and efficient work-up of a mediastinal mass. Patients with primary mediastinal masses and cysts will usually undergo surgical resection; radiological and clinical features should prompt limited biopsy specimens followed by oncologic consultation, and chemotherapy or radiotherapy when appropriate. The objective of this review was to examine the role of diagnostic imaging in the management of masses of the anterior mediastinum.

In CT-guided transthoracic needle biopsy, the final diagnosis and lesion size affect diagnostic accuracy: benign lung lesions and lesions smaller than 1.5 cm or larger than 5.0 cm in diameter provide lower diagnostic yield.

With dual-echo chemical-shift MR imaging, SII signal intensity index and CSR chemical-shift ratio have high accuracy to distinguish thymic hyperplasia from tumors, although overlapped CSR chemical-shift ratio values can occur in early adulthood.