Low prevalence of incidentally discovered and early-stage esophageal cancers in a 30-year autopsy study.

Autopsy studies provide information that may guide future patient management. This study analyzed autopsy findings in patients with esophageal cancers, with emphasis on the prevalence of incidentally diagnosed esophageal cancer, histologic subtypes, early-stage lesions, and any associated pathology. Autopsies detected 346 patients (306 men; 40 women) with esophageal carcinomas during a 30-year period, constituting an overall prevalence of 3.4%. Out of these patients, 30 (8.7%) were incidentally discovered at autopsy. Squamous cell cancers were found in 336 (97.1%) patients, small cell cancers in nine (2.7%), and adenocarcinomas in one (0.3%). Stage distributions were stage I in seven patients (2%), stage II in 49 (14%), stage III in 121 (35%), and stage IV in 169 (49%). Isolated dysplasia or carcinoma-in-situ were not found. Comparing with symptomatic patients, patients with incidental cancers were older, had higher frequency of small cell carcinomas, and lower T-stage. The prevalence of incidentally diagnosed esophageal carcinomas and early-stage carcinomas were low. Unusual histologic subtypes may be found.

Metastatic tumours of the adrenal glands: a 30-year experience in a teaching hospital.

OBJECTIVE: Adrenal metastases are frequently encountered during autopsy but uncommonly present clinically. The aim of this study was to evaluate the clinical and pathological impact of adrenal metastases in a large series of patients. PATIENTS: Four hundred and sixty-four patients (288 men, 176 women) with metastatic disease in the adrenal glands over a 30-year period were included in the study. MEASUREMENTS: The clinical records and pathological features were reviewed. RESULTS: The frequencies of adrenal metastases at autopsies, adrenalectomies and fine-needle aspiration biopsies were 3.1%, 7.5% and 33%, respectively. The lesions were often seen in elderly patients (mean age, 62, SD = 13 years). Many of the metastatic lesions in the adrenal gland occurred shortly after the detection of a primary tumour (mean latent period = 7 months). Four per cent of the adrenal lesions (n = 20) were symptomatic. The symptomatic adrenal lesions, as compared with asymptomatic ones, were bigger and seen in younger patients. Five patients presented with adrenal insufficiency (Addison's disease) and one had massive peritoneal haemorrhage because of metastatic carcinoma. Ninety per cent (n = 421) of the metastatic adrenal tumours were carcinomas and 56% of these were adenocarcinoma. Lung was the most common primary tumour site (35%), followed by the stomach (14%), the oesophagus (12%) and the liver/bile ducts (10%). The adrenal metastases were bilateral in approximately half of the patients (49%, n = 229). The mean diameter of the adrenal metastases was 2 cm (SD = 1.9 cm). The mean weight of the right adrenal gland harbouring the metastasis was 19 g, while that of the left 20 g. The median survival of the 20 patients with symptomatic adrenal lesions was 3 months (range, 0-75 months) after the detection of adrenal metastases. Patients with surgically removed adrenal metastases had slightly better survival rates than those without surgical resection. CONCLUSIONS: A variety of tumours may give rise to adrenal metastases. They are often asymptomatic and detected as part of multiorgan metastases. Symptomatic cases, albeit rare, may occur. Long-term survival may be achieved in selected patients in whom an aggressive surgical approach may be adopted.

Dispersion and characteristic surfaces of waves in laminated composite circular cylindrical shells

The dispersion behaviors and characteristic surfaces of waves in a laminated composite circular cylindrical shell are investigated using a semianalytical method based on the theory of three-dimensional elasticity. The radial displacement of the shell is modeled by finite elements, while the axial and circumferential displacements are expanded as the complex exponentials. The associated characteristic equation is developed by means of the Hamilton's principle. The eigenvalues are established in terms of the Rayleigh quotient. Six characteristic wave surfaces, viz., the phase velocity, phase slowness, and phase wave surfaces, as well as the group velocity, group slowness, and group wave surfaces, are introduced to visualize the effects of anisotropy on wave propagation. Numerical examples demonstrate that the ratio of the inner radius to the thickness of the shell has a stronger influence on the frequency spectra in the circumferential wave than on that in the axial wave; that negative group velocity appears at a range of smaller wave numbers and the range varies as the wave normal and the ratio of the inner radius to the thickness of the shell; and that the characteristic wave surfaces vary with the propagation modes of waves, the ratio of the inner radius to the thickness of the shell, and the lay-ups of the laminated shells.

A strip-element method for analyzing wave scattering by a crack in an immersed axisymmetric laminated composite cylinder

A strip-element method is presented for analyzing wave scattering by a crack in a laminated composite cylinder immersed in a fluid. In this approach, two-nodal-line and three-nodal-line axisymmetric strip elements are employed to model the fluid and laminated cylinder, respectively. Governing equations for the fluid and solid elements in the frequency domain are derived with a variational method and the Hamilton principle. The associated characteristic equations in the wave-number domain are obtained through Fourier transform techniques. Responses of the fluid-loaded cylinder to a line load are found by a modal-analysis method and inverse Fourier transform techniques. Numerical results are presented for cracked laminated composite cylinders submerged in water. Water is found to have strong influence on the scattered wave fields in a cracked laminated composite cylinder.