Faculty Bibliography

We report on the utility of computed tomography (CT) in making the diagnosis of primary aortoduodenal fistulas in two cases presenting with massive gastrointestinal hemorrhage. In both cases, the clinical presentation was insidious, no pulsatile abdominal mass was palpated, and endoscopy findings were inconclusive. CT showed minimally aneurysmal aortas communicating with larger areas of contained rupture and pseudoaneurysm stretching adjacent small bowel.

Hibernomas are benign tumors derived from brown fat that most often present as painless, slowly enlarging masses in the interscapular region. Because these lesions have a heterogeneous appearance and contain fat, they mimic liposarcomas on CT and MR, requiring biopsy for definitive diagnosis.

Although opportunistic infections of the esophagus occur commonly in acquired immunodeficiency syndrome (AIDS), inflammation is generally limited to the mucosal surface. During a 7-month interval, six men at risk for AIDS underwent barium esophagography because of persistent symptoms of esophageal disease. In each case, transmural inflammation of the esophagus was found (esophagomediastinal communication in three cases and esophagobronchial fistulas in three cases). Two patients had an esophagoesophageal fistula, an inflammatory lesion that has not, to the authors' knowledge, been previously described with mycobacterial infection. Mycobacterial infection was documented by means of culture findings in all six patients (Mycobacterium tuberculosis in five, M avium in one). In three cases mycobacteria were either seen in or cultured from esophageal biopsy specimens. The finding of deep esophageal ulceration, intramural dissection, or fistula formation in a patient with AIDS should suggest the diagnosis of esophageal tuberculosis.

A malposition of the superior mesenteric vein on cross-sectional imaging was seen in four adult patients with malrotation of the bowel and is diagnostic of this entity. This sign should be looked for on CT or magnetic resonance to explain ill defined symptomatology and to define who may be at risk for future complications. We also define a 'pseudo-superior mesenteric artery-vein sign' due to mass displacement of the pancreas, which must be distinguished from true malrotation