CT of primary cystic pancreatic neoplasms: can CT be used for patient triage and treatment?

OBJECTIVE: The purpose of this study was to determine whether CT can be used to distinguish serous cystadenomas from mucinous cystadenomas or cystadenocarcinomas of the pancreas and play an enhanced role in patient triage and treatment. MATERIALS AND METHODS: A blinded retrospective analysis of CT scans from 50 patients with pathologically proven primary cystic pancreatic neoplasms was performed independently by three radiologists. Using classic CT criteria as reported in the literature, each tumor was categorized as definitely serous, mucinous, or indeterminate. Tumor location, size, presence of calcification, and size of largest cyst were recorded. Data for each reviewer were analyzed independently. Consensus data were then subjected to multivariate logistic regression analysis. RESULTS: The ability of our reviewers to diagnose serous neoplasms ranged from 23% to 41%. Eight mucinous neoplasms were mistaken for serous tumors by two of the three reviewers. When consensus between at least two of the three reviewers was used for diagnosis, 27% of serous neoplasms were correctly diagnosed and all of the mucinous tumors were correctly identified as uncertain or mucinous, yielding the same clinical end point. For multivariate logistic regression analysis, a cyst smaller than 2 cm had a statistically significant association (p = 0.005) with serous tumors, and the presence of peripheral tumoral calcification had a statistically significant association (p = 0.01) with mucinous tumors. CONCLUSION: There is significant variability in the CT appearance of serous and mucinous neoplasms of the pancreas, making CT an insensitive tool for differentiating these tumors. All tumors with peripheral calcifications were identified as mucinous neoplasms.

Pulmonary gangrene: radiological and pathologic correlation.

Although frequently referred to as pulmonary abscess or necrotizing pneumonia, pulmonary gangrene is a distinct entity, requiring prompt medical and often surgical management. Radiographically, it begins as a lobar consolidation, usually in the upper lobes, develops lucencies, and coalesces to form a cavity. A "mass within a mass" or air crescent sign may be present. A vasculitis ensues, devitalizing parenchyma that must be drained surgically or expectorated through a patent bronchus. Serious complications of pulmonary gangrene that often lead to death are detected on computed tomography (CT) before these changes are apparent on chest radiographs. Specifically, a narrowed or obliterated bronchus impedes drainage of necrotic parenchyma and thrombosis of large vessels prevents the delivery of antimicrobial therapy. We review the literature and report this case to show the importance of CT in the early detection and management of pulmonary gangrene.

Urinary organic anion excretion in response to dietary acid and base loading.

Animals eating a base-loaded or base-forming diet excrete urine containing large amounts of organic anions (OA). Although citrate is the only OA previously identified as being excreted in appreciable amounts during base loading, citrate excretion accounts for only part of total OA excretion. The objectives of this study were to identify other OA excreted by rats and to see how their excretion changed in response to moderate (8 micro Eq/g per day) and heavy (30 micro Eq/g per day) loads of NaHCO3 and NH4Cl. Urinary OA were identified by high-performance liquid chromatography and were measured by enzymatic techniques as well. It was found that, in addition to citrate, significant quantities of alpha-ketoglutarate (alpha-KG) were excreted by base-loaded rats and that the excretion of citrate, alpha-KG, and succinate increased with base loading and decreased with acid loading. Citrate plus alpha-KG excretion rates were, respectively, two-thirds and one-third the rate of HCO3- excretion in rats given moderate and heavy base loads. The excretion of creatinine, glutamine, and hippurate showed no clear pattern in response to acid or base loading. It was concluded that, especially in animals experiencing moderate base loads, increases in the excretion of citrate and alpha-KG represent a much more significant component of base excretion than has been recognized previously.

The hemostatic mechanism after open-heart surgery. III. Correlation between the appearance of an abnormal protein demonstrated by gel electrophoresis and of an inhibitor of the extrinsic coagulation system (PEC).

A prospective study in 13 patients undergoing open-heart surgery with extracorporeal circulation revealed a marked decrease of the mean one-stage prothrombin time activity from 88% to 54% (p less than 0.005) but lesser decreases of factors I, II, V, VII and X. This apparent discrepancy was due to the appearance of an inhibitor of the extrinsic coagulation system, termed PEC (Protein after Extracorporeal Circulation). The mean plasma PEC level rose from 0.05 U/ml pre-surgery to 0.65 U/ml post-surgery (p less than 0.0005), and was accompanied by the appearance of additional proteins as evidenced by disc polyacrylamide gel electrophoresis of plasma fractions (p less than 0.0005). The observed increases of PEC, appearance of abnormal protein bands and concomitant increases of LDH and SGOT suggest that the release of an inhibitor of the coagulation system (similar or identical to PIVKA) may be due to hypoxic liver damage during extracorporeal circulation.