We characterized the pathologic spectrum of lesions in gastrointestinal and hepatic histoplasmosis by studying cases of disseminated disease in immunocompromised and immunocompetent patients from endemic and nonendemic areas. We evaluated 56 specimens from 52 patients with H&E and silver stains. Of these patients, 43% presented with gastrointestinal rather than pulmonary symptoms. Thirty-one percent had gastrointestinal lesions, 10% had liver lesions, and 43% had both. Gross gastrointestinal features included ulcers (49% of patients), nodules (21%), hemorrhage (13%), obstructive masses (6%) and normal mucosa (23%). Microscopic gastrointestinal findings included diffuse lymphohistiocytic infiltration (83%), ulceration (45%), lymphohistiocytic nodules (25%), or minimal inflammatory reaction (15%) but only rare well-formed granulomas (8.5%). The most common hepatic finding was portal lymphohistiocytic inflammation; discrete hepatic granulomas were seen in less than 20% of involved livers. The pathologist must be aware of the broad range of gastrointestinal and hepatic lesions produced by histoplasmosis and, in particular, that well-formed granulomas are rare. Given the appropriate clinical context, histoplasmosis should be considered in both immunocompetent and immunocompromised patients, regardless of pulmonary symptoms, in nonendemic as well as endemic areas.

Hantavirus pulmonary syndrome (HPS) is a severe and often fatal rodent-borne zoonosis. Maporal (MAP) virus is a newly discovered hantavirus that originally was isolated from an arboreal rice rat captured in central Venezuela. The results of this study indicate that MAP virus in the Syrian golden hamster (Mesocricetus auratus) can cause a disease that is clinically and pathologically remarkably similar to HPS. The similarities include the time course of clinical disease, presence of virus-specific IgG at the onset of clinical disease, subacute pneumonitis, rapid onset of diffuse alveolar edema in the absence of necrosis, hepatic-portal triaditis, mononuclear-cellular infiltrate in lung and liver, widespread distribution of hantaviral antigen in endothelial cells of the microvasculature of lung and other tissues, and variable lethality. These similarities suggest that the MAP virus-hamster system is a useful model for studies of the pathogenesis of HPS and for the evaluation of potential therapeutic agents.

Haemoglobin F (Hb F) levels were determined in 209 full-term newborn babies or infants of different ages ranging from birth to 11 months. A follow-up study of the disappearance of Hb F after birth was carried out on 25 premature babies; they were followed periodically from birth until 8 months. The results obtained in both samples show that Hb F levels remain constant after birth for periods varying from about 15 d in at term babies to about 40 d in premature babies; a linear decrease follows in both cases. The initial plateau is a finding contrary to what has been reported. A possible model for the phenomenon is discussed in terms of haemoglobin genes and ontogenetic differentiation.

The true incidence of herpetic infections of the larynx is unknown. This entity may be underreported because of the difficulty in establishing the diagnosis. This report describes an immune-competent patient in whom extubation failed because of mass lesions of the posterior glottis. A biopsy specimen of the lesions revealed herpes simplex virus. We review the clinical presentation and histopathologic findings in this patient.

Context.—Endoscopic brush cytology is a valuable technique for the diagnosis of pancreatobiliary malignancy. Despite its widespread use, the sensitivity of this method has been reported as approximately 50%. The specificity is usually higher than 95%. Few reports have systematically analyzed the reasons for this relatively low sensitivity. Objectives.—To determine the rate and reasons for false-negative diagnoses in endoscopic brushing cytology of biliary and pancreatic ducts based on the results of sensitivity, specificity, accuracy, and positive and negative predictive values. Design.—Retrospective analysis of laboratory data and slide review of false-negative cases. Setting.—Two tertiary care state university hospitals. Patients.—A total of 183 pancreatobiliary brushing specimens obtained from patients undergoing endoscopic retrograde cholangiopancreatography for biliary or pancreatic duct disease for a 4- to 5-year period. Intervention.—Endoscopic retrograde cholangiopancreatography brushings. Main Outcome Measures.—Determination of sensitivity, specificity, accuracy, and positive and negative predictive values. Analysis of false-negative results. Results.—The sensitivity, specificity, accuracy, and positive and negative predictive values, overall, were 48%, 98%, 79%, 92%, and 76%, respectively. Sampling error was a major cause of false-negative diagnoses (67%), followed by interpretive (17%) and technical errors (17%). Conclusions.—Improvements in sensitivity and diagnostic accuracy for cancer of the pancreatobiliary tract can be achieved by optimizing slide preparatory techniques. Also, enhancement of the cytologist's diagnostic skills enables the identification of the morphologic features of premalignant lesions. Repeat brushings are indicated for suspicious or negative results not consistent with the clinical or radiologic findings.