Structural characterization and distribution of elastic system fibers in the human prostate and some prostatic lesions

Prostatic disorders are accompanied by extensive but poorly understood modifications of the cells and surrounding extracellular matrix. In this study, we examined the distribution of the elastic system fibers in prostatic disorders compared to normal tissue. Sections of prostatic transurethral resections and/or radical prostatectomies were examined after staining with hematoxylin-eosin plus fluorescence microscopy and after Weigert's staining for elastic fibers. Transmission electron microscopy was used to examine the ultrastructure of tissues from radical prostatectomy. A concentric fibrous extracellular matrix and smooth muscle cells were observed surrounding normal acini. The elastic fibers were thin and inconspicuous. In benign prostatic hyperplasia (BPH) the elastic components were of variable thickness and formed a three-dimensional network at the base of the epithelium. Conversely, increased variability in the elastic fiber distribution was observed in adenocarcinomas, depending on the tumor grade. In adenocarcinomas with little differentiation, in some hyperplasic acini, and in the stroma adjacent to tumoral mass, ruptured and residual elastic fibers indicative of matrix degradation or remodeling were seen. In more undifferentiated tumors, a pre-elastic network, perhaps indicative of a new extracellular matrix microenvironment was seen. These results indicate that prostate cancer cell invasion involves extensive remodeling of the fibers of the elastic system.

Low grade adenocarcinoma simulating benign glandular lesions in needle prostatic biopsy

Con el fin de definir la frecuencia y las características morfológicas de los adenocarcinomas de bajo grado que fueron confundidos con proliferaciones glandulares benignas, revisamos retrospectivamente 135 biopsias con carcinoma prostática. Tres biopsias (2.2 por ciento) mostraron adenocarcinomas de bajo grado en campos aislados que semejaban glándulas hiperplásicas en algunos campos histológicos y adenosis prostática en otros. Estas tres biopsias mostraron retrospectivamente características del adenocarcinoma prostático originado en la zona de transición. Algunos criterios de malignidad como el patrón infiltrante, los núcleos y nucléolos prominentes fueron observados aisladamente. No se identificaron secreciones basófilas intraluminales, cristaloides, células neoplásicas aisladas en el estroma ni mitosis en ningún caso. Concluímos que el análisis detallado de las características arquitecturales y citológicas de las proliferaciones glandulares prostáticas es necesario ya que el adenocarcinoma de bajo grado se puede encontrar esporádicamante como patrón histológico único en las biopsias por punción semejando lesiones glandulares benignas