Getting the GIST: a pictorial review of the various patterns of presentation of gastrointestinal stromal tumors on imaging.

Gastrointestinal stromal tumors (GISTs), the most common mesenchymal tumors of the gastrointestinal tract, are a relatively recently described entity. Most exhibit a mutated tyrosine kinase receptor gene and in some capacity are treated by tyrosine kinase inhibitors. GISTs can occur across the age spectrum but are more common in patients older than 40 years. They exhibit a wide range of clinical presentations and imaging characteristics. All patterns of enhancement on contrast enhanced computed tomography (CECT) can be seen with GISTs, including hypoenhancing, isoenhancing, and hyperenhancing tumors. They can be large or small, endoluminal or exophytic. Clinical presentations include asymptomatic patients, nonspecific symptoms, obstruction, and bleeding. Bleeding can take the form of slow, intraluminal GI bleeding or massive intraperitoneal bleeding secondary to rupture and can be seen regardless of the enhancement pattern. Some can cavitate, ulcerate, rupture or cause fistulae. The radiologist's knowledge of the variety of combinations of presentations can narrow the differential diagnosis and ultimately lead to faster diagnosis and treatment.

Multidetector CT enterography of focal small bowel lesions: a radiological-pathological correlation.

Focal small bowel lesions present a diagnostic challenge for both the radiologist and gastroenterologist. Both the detection and characterization of small bowel masses have greatly improved with the advent of multidetector CT enterography (MD-CTE). As such, MD-CTE is increasingly utilized in the workup of occult gastrointestinal bleeding. In this article, we review the spectrum of focal small bowel masses with pathologic correlation. Adenocarcinoma, the most common primary small bowel malignancy, presents as a focal irregular mass occasionally with circumferential extension leading to obstruction. Small bowel carcinoid tumors most commonly arise in the ileum and are characterized by avid enhancement and marked desmoplastic response of metastatic lesions. Aneurysmal dilatation of small bowel is pathognomonic for lymphoma and secondary findings of lymphadenopathy and splenomegaly should be sought. Benign small bowel masses such as leiomyoma and adenoma may be responsible for occult gastrointestinal bleeding. However, primary vascular lesions of the small bowel remain the most common cause for occult small bowel gastrointestinal bleeding. The arterial phase of contrast obtained with CTE aids in recognition of the vascular nature of these lesions. Systemic conditions such as Peutz-Jeghers syndrome and Crohn's disease may be suggested by the presence of multiple small bowel lesions. Lastly, potential pitfalls such as ingested material should be considered when faced with focal small bowel masses.

Etiology, Diagnosis, and Management of Bilomas: A Current Update.

A biloma is a well-demarcated collection of bile outside the biliary tree. Traumatic and iatrogenic injuries, most commonly secondary to cholecystectomy, are the usual causes. Although bilomas are relatively uncommon, this pathologic entity may lead to significant morbidity and mortality if not promptly diagnosed and properly managed. As clinical signs and symptoms of bilomas are often nonspecific and laboratory values may be unremarkable, imaging modalities including ultrasound, computed tomography, magnetic resonance imaging, and hepatobiliary cholescintigraphy play a crucial role in the diagnosis of this condition. It is paramount that interventional radiologists not only be well versed in the management of bilomas but also be knowledgeable in the diagnosis as well as key imaging findings that dictate the interventional management. The purpose of this article is to review the etiology, pathophysiology, and clinical presentation of bilomas to primarily focus on the relevant multimodal imaging findings and the minimally invasive management options.

Systemic mastocytosis: a rare cause of single vertebral body uptake on bone scan.

Systemic Mastocytosis is a rare condition characterized by the abnormal proliferation of Mast Cells. Presentation as a solitary vertebral body lesion is extremely uncommon and may be confused with more ominous conditions such as metastasis. Familiarity with the condition can heighten clinical suspicion, direct tissue diagnosis, guide management and indicate appropriate follow up. We present a case of a 64-year-old woman undergoing staging for recently diagnosed breast cancer who was found to have Systemic Mastocytosis of a single vertebral body.