Anatomic and functional imaging of metastatic carcinoid tumors.

Carcinoid tumors are a fascinating group of neuroendocrine neoplasms that develop either sporadically or as part of an inheritable syndrome. Many tumors arise in the bronchopulmonary or gastrointestinal tract, but a neuroendocrine tumor can arise in almost any organ. The tumors have varied malignant potential depending on the site of their origin, and the clinical manifestations often are nonspecific. Metastases may be present at the time of diagnosis, which often occurs at a late stage of the disease. Imaging plays a pivotal role in the localization and staging of neuroendocrine tumors and in monitoring the treatment response. Imaging is often challenging, and a combination of anatomic and functional techniques is usually required, depending on the tumor type and location. Techniques include ultrasonography, barium studies, endoscopy, computed tomography, magnetic resonance imaging, somatostatin receptor scintigraphy, iobenguane scintigraphy, and, in select cases, positron emission tomography. Coregistration of structural and functional images is often of incremental value for accurate localization of the primary tumor and any meta-static disease. Radiologists must understand the contribution of each imaging modality in the assessment of different neuroendocrine tumors. In addition, knowledge of the optimal technique for each radiologic and radionuclide imaging examination is essential. Familiarity with the protean imaging appearances of both primary and metastatic disease is essential for accurate staging, treatment monitoring, and surveillance. Finally, an understanding of the wide variety of treatment options for patients with carcinoid tumors is vital for optimal management.

Quantification of missing and overlapping data in multiple breath hold abdominal imaging.

Magnetic resonance imaging (MRI) of the abdomen is often performed in multiple breath holds which are designed to contiguously cover the region of interest. This technique may result in a failure to image all the appropriate area, and the extent of this failure is difficult to appreciate on a set of 2D slices. With reference to three patient cases, we present a method to quantify the extent of this problem and suggest a solution. First, we manually delineate the region of interest on a single breath hold fast spoiled gradient echo (FSPGR) sequence. Subsequently, we align images acquired in separate breath holds to this reference volume. A coloured 3D presentation makes the extent of unimaged and repeatedly imaged areas clearly visible to the clinician. The alignment also helps radiologists to accurately determine the location of individual slices. The described method can easily be automated and is ideally implemented at the scanner console, ensuring the availability of contiguously sampled datasets to radiologists with minimum user interaction from the radiographer. Such datasets enable the deployment of robust 3D analysis algorithms.

Multiple endocrine neoplasia: spectrum of radiologic appearances and discussion of a multitechnique imaging approach.

Multiple endocrine neoplasia (MEN) is characterized by the occurrence of two or more tumors that may be associated with hyperfunction and malignancy. MEN is caused by genetic defects, and two major types, MEN 1 and MEN 2, are recognized. Each type is characterized by the development of tumors within specific endocrine organs. A multidisciplinary approach involving cooperation between endocrinologists, surgeons, oncologists, and radiologists is pivotal for optimizing patient treatment. Imaging plays a vital role in the diagnosis and management of the disease. To contribute effectively, however, the radiologist must understand the range of anatomic and functional imaging modalities used in the assessment of endocrine disorders. In addition, knowledge of the optimal techniques for evaluating the pituitary, thyroid, parathyroid, pancreatic, adrenal, and foregut carcinoid tumors that occur in these MEN syndromes is essential. Finally, an understanding of the spectrum of disease and of the manifestations of each component is crucial for accurate detection, staging, and surveillance in this diverse patient group.

Asymptomatic children with multiple endocrine neoplasia type 1 mutations may harbor nonfunctioning pancreatic neuroendocrine tumors.

CONTEXT: Multiple endocrine neoplasia type 1 (MEN1) is characterized by the occurrence of parathyroid, pituitary, and pancreatic tumors. MEN1, an autosomal dominant disorder, has a high degree of penetrance, such that more than 95% of patients develop clinical manifestations by the fifth decade, although this is lower at approximately 50% by age 20 yr. However, the lower penetrance in the younger group, which is based on detecting hormone-secreting tumors, may be an underestimate because patients may have nonfunctioning tumors and be asymptomatic. OBJECTIVE: The aim of the study was to evaluate the occurrence of nonfunctioning pancreatic neuroendocrine tumors in asymptomatic children with MEN1. PATIENTS: Twelve asymptomatic Northern European children, aged 6 to 16 yr, who were known to have MEN1 mutations were studied. RESULTS: Two asymptomatic children, who were aged 12 and 14 yr, had normal plasma fasting gastrointestinal hormones and were found to have nonfunctioning pancreatic neuroendocrine tumors that were more than 2 cm in size. Surgery and immunostaining revealed that the tumors did not have significant expression of gastrointestinal hormones but did contain chromogranin A and synaptophysin, features consistent with those of nonfunctioning pancreatic neuroendocrine tumors. The tumors had a loss of menin expression. The 14 yr old also had primary hyperparathyroidism and a microprolactinoma, and the 12 yr old had a nonfunctioning pituitary microadenoma. Three other children had primary hyperparathyroidism and a microprolactinoma. CONCLUSION: Nonfunctioning pancreatic neuroendocrine tumors may occur in asymptomatic children with MEN1 mutations, and screening for such enteropancreatic tumors in MEN1 children should be considered earlier than the age of 20 yr, as is currently recommended by the international guidelines.