Encapsulated apocrine papillary carcinoma of the breast--a tumour of uncertain malignant potential: report of five cases.

Five cases of an unusual encapsulated apocrine papillary tumour are reported. All presented as cystic masses in the breast of women aged 44-84 years. Imaging studies showed a complex cyst often with one or more mural nodules. The key histological features are similar to those of classical encapsulated papillary carcinoma in that myoepithelial cells were absent within the papillary structures and at the periphery of the cyst. All were pure apocrine in type and showed variable degrees of cytological atypia and mitotic activity. All lacked evidence of malignancy in the breast tissue outside of the lesion. Sentinel lymph node biopsies performed in three of the cases were negative for metastases, and all have behaved in a benign fashion.

Development of visual diagnostic expertise in pathology -- an information-processing study.

OBJECTIVE: To identify key features contributing to trainees' development of expertise in microscopic pathology diagnosis, a complex visual task, and to provide new insights to help create computer-based training systems in pathology. DESIGN: Standard methods of information-processing and cognitive science were used to study diagnostic processes (search, perception, reasoning) of 28 novices, intermediates, and experts. Participants examined cases in breast pathology; each case had a previously established gold standard diagnosis. Videotapes correlated the actual visual data examined by participants with their verbal "think-aloud" protocols. MEASUREMENTS: Investigators measured accuracy, difficulty, certainty, protocol process frequencies, error frequencies, and times to key diagnostic events for each case and subject. Analyses of variance, chi-square tests and post-hoc comparisons were performed with subject as the unit of analysis. RESULTS: Level of expertise corresponded with differences in search, perception, and reasoning components of the tasks. Several discrete steps occur on the path to competence, including development of adequate search strategies, rapid and accurate recognition of anatomic location, acquisition of visual data interpretation skills, and transitory reliance on explicit feature identification. CONCLUSION: Results provide the basis for an empirical cognitive model of competence for the complex tasks of microscopic pathology diagnosis. Results will inform the development of computer-based pedagogy tools in this domain

Memory CD4(+) T cells are the earliest detectable human immunodeficiency virus type 1 (HIV-1)-infected cells in the female genital mucosal tissue during HIV-1 transmission in an organ culture system.

The virologic and cellular factors that are involved in transmission of human immunodeficiency virus type 1 (HIV-1) across the female genital tissue are poorly understood. We have recently developed a human cervical tissue-derived organ culture model to study heterosexual transmission of HIV-1 that mimics the in vivo situation. Using this model we investigated the role of phenotypic characteristics of HIV-1 and identified the cell types that are first infected during transmission. Our data indicate that the cell-free R5 HIV-1 was more efficiently transmitted than cell-free X4 HIV-1. Cell-free and cell-associated HIV-1 had comparable transmission efficiency regardless of whether the virus was of R5 or X4 type. We have demonstrated that memory CD4(+) T cells and not Langerhans cells were the first HIV-1 RNA-positive cells detected at the epithelial-submucosal junction 6 h after virus exposure. Multicolor laser confocal microscopy demonstrated a globular distribution of HIV-1 gag-pol mRNA in the cytoplasm, and the distribution of CD4 and the CD45RO isoform was irregular on the cellular membrane. At 96 h postinoculation, in addition to memory CD4(+) T cells, HIV-1 RNA-positive Langerhans cells and macrophages were also detected. The identification of CD4(+) T cells in the tissue at 6 h was confirmed by flow cytometric simultaneous immunophenotyping and ultrasensitive fluorescence in situ hybridization assay on immune cells isolated from disaggregated tissue. Furthermore, PMPA [9-[2-(phosphonomethoxy)propyl] adenine], an antiretroviral compound, and UC781, a microbicide, inhibited HIV-1 transmission across the mucosa, indicating the utility of the organ culture to screen topical microbicides for their ability to block sexual transmission of HIV-1.