FDG-PET evaluation of indeterminate pancreatic masses.

PURPOSE: The purpose of this study was to assess the ability of PET with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) to differentiate benign from malignant pancreatic masses in patients with indeterminate findings on CT. METHOD: We performed FDG-PET on 12 patients with indeterminate mass lesions and 2 patients with CT findings typical for malignancy. Eight were found to have pancreatic carcinoma and six had benign lesions. The final diagnosis was histopathologically confirmed in all patients but two with a presumed diagnosis of focal pancreatitis based on stable clinical follow-up for at least 12 months. Lesion uptake of FDG was evaluated qualitatively and semiquantitatively by determination of the standardized uptake value (SUV) RESULTS: With use of a 2.5 cutoff value for SUV, all eight malignant and four of six benign lesions were correctly categorized. Qualitative evaluation gave the same results. The two false-positive lesions had elevated SUV values of 3.4 and 3.8, respectively. CONCLUSION: Our results indicate that FDG-PET has potential value for assessing patients with CT findings that are indeterminate for pancreatic carcinoma. FDG-PET may obviate invasive diagnostic procedures in many patients with benign disease.

Cervical esophageal web associated with a patch of heterotopic gastric mucosa.

Cervical esophageal webs are a relatively common finding on esophograms. We report a web resulting from the squamocolumnar junction produced by heterotopic gastric mucosa. The clinical significance of this lesion is discussed and the importance of differentiating it from Barrett's esophagus is stressed.

Glycosphingolipid biosynthesis during myogenesis of rat L6 cells in vitro.

Glycosphingolipid biosynthesis was examined using [3H]-galactose as a precursor as rat L6 myoblasts fused to form multinucleated myotubes. Incorporation of label into neutral glycolipids decreased steadily as the population of myotubes increased, so that final biosynthesis was one-half that observed with myoblasts (p less than 0.02). Conversely, ganglioside biosynthesis doubled during myoblast confluency (p less than 0.02) and then decreased as myotubes formed. Qualitatively, L6 cells synthesized large amounts of ganglioside GM3 during all myogenic phases. The major neutral glycosphingolipid products were lactosylceramide and paragloboside (nLcOse4Cer). Few changes in TLC autoradiographic patterns were noted during differentiation, with the exception of a slight decrease in ganglioside GM1. The results indicate that the biosynthesis of glycosphingolipids is tightly regulated during myogenesis in vitro and suggest a role for membrane gangliosides in muscle cell differentiation.

Glycosphingolipids of an alveolar rhabdomyosarcoma and normal human muscle. A case study.

The distribution of neutral, or asialosyl-, glycosphingolipids and gangliosides in a rhabdomyosarcoma of alveolar type have been studied. Histologically, this muscle tumor is composed primarily of two cell types: one with oval or round hyperchromatic nuclei and very little cytoplasm, and one a giant cell, with multiple, peripherally placed nuclei and weakly staining eosinophillic cytoplasm. In comparing glycolipids of the rhabdomyosarcoma with normal muscle from the same leg, the striking alteration in the tumor was a virtual disappearance of ganglioside GM2. There was also a slight increase in GM3 and a decrease in GD1a. The asialosyl derivative of GM2 (GalNac-Gal-Glc-Cer) was markedly increased in the tumor. A loss of glucosylceramide was also observed. The results are discussed in terms of glycolipid metabolic changes in muscle oncogenesis and their implications.