Squamous differentiation is identified in about 25% of endometrial adenocarcinomas (AC). Its significance has been the subject of debate for decades, and it has been reported that the prognosis of adenoacanthoma (AA) is better than, the same as, and worse than that of AC. Part of this confusion has resulted from semantic differences relating to the use of AA and adenosquamous carcinoma (AS). To investigate the prognostic importance of squamous differentiation in endometrial carcinomas and compare the prognostic utility of two classification systems, 456 women were studied who had typical AC and 175 women who had typical AC containing areas of squamous differentiation (AC + SQ) and who had been entered in a Gynecologic Oncology Group protocol of Stage I and II endometrial adenocarcinoma. Assessment of histologic grade and depth of invasion was done both by the pathologist at the member institution and at a second highly structured review. Differentiation of the squamous component of endometrial carcinomas was found to parallel that of the glandular component in most tumors. The biologic behavior of endometrial carcinomas with squamous elements was similar, but not identical, to that of typical AC. Although the frequency of nodal metastasis was similar for both AC and AC + SQ, the presence of squamous elements was associated with an increased probability of survival. Division of AC + SQ by depth of myometrial invasion and by architectural grade of the glandular component provided useful prognostic information that was superior to that resulting simply from division of AC + SQ into AA or AS. The authors recommend that these terms be replaced by “adenocarcinoma with squamous differentiation” and that the pathologist provide information on the architectural grade and depth of myometrial invasion to guide the gynecologist in determining appropriate therapy. Cancer 68:2293–2302, 1991.

Cultured mosquito cells were found to produce Sindbis virus nearly as efficiently as BHK-21 cells at 28 C. In virtually all of the cells observed in the electron microscope, virus morphogenesis was found to occur within complex vesicular structures which developed after viral infection. Viral nucleocapsids were first seen in these vesicles and appeared to be enveloped within these structures. The process of envelopment within these inclusions differed in some respects from the process previously described for the envelopment of nucleocapsids at the plasma membrane of vertebrate cells. Free nucleocapsids were only rarely seen in the cytoplasm of infected mosquito cells, and budding of virus from the cell surface was detected so infrequently that this process of virus production could not account for the amount of virus produced by the infected cells. The vast majority of extracellular virus was produced by the fusion of the virus-containing vesicles with the plasma membrane releasing mature virions and membrane nucleocapsid complexes in various stages of development.

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The angiographic, morphologic, and histologic effects of carbon microspheres, isobutyl 2-cyanoacrylate (IBC), and low viscosity silicone rubber (LVSR) were compared. Carbon spheres did not effectively occlude the internal iliac artery, but resulted in small vessel occlusions leading to the most frequent complications. IBC was effective in causing occlusion but resulted in significant inflammatory changes within the thrombus and vessel wall. LVSR gave satisfactory occlusion without inciting vessel wass inflammatory reaction. Two of 4 animals developed a hind extremity paralysis. None of these materials is approved for general intravascular usage.

The classification of patients with incidental carcinoma of the prostate into focal (Stage A1) or diffuse (Stage A2) subgroups depends primarily on the microscopic findings on tissue removed from transurethral resection (TUR) or open enucleation. However, these procedures sample only a portion of the entire prostate, and some patients staged A1 may have residual diffuse cancer that should properly be classified as Stage A2. This study is a review of 86 patients with Stage A1 cancer of the prostate in whom additional prostatic tissue was available because of repeat transurethral resection or radical prostatectomy. Only six patients (7%) were found to have diffuse cancer in the remaining prostatic tissue. Therefore, it appears that the classification of patients into Stage A1 or Stage A2 is generally accurate when based on the findings from initial TUR alone and that the incidence of understaging in this group is low. Repeat transurethral resection does not appear to contribute significantly to the accuracy of staging.