An unusual small intestinal tumor was found in a 61-year-old male who complained of intermittent right lower quadrant burning pain, tenesmus, and bloody diarrhea. On gross examination, the tumor was located intramurally in the distal jejunum with no involvement of the overlying mucosa. Histologic examination revealed two elements: a spindle cell component with characteristics reminiscent of a Schwann cell neoplasm, and nests of larger epithelioid-like cells almost undistinguishable from the Zellballen of nonchromaffin paragangliomas. The neoplasm originated within the intestinal wall without apparent mucosal origin. Ultrastructural studies revealed features recapitulating the normal enteric plexus structure and quite unlike those described in normal or neoplastic smooth muscle, Schwann or paraganglion cells. On this basis, this neoplasm is considered as a malignant enteric plexus tumor or a plexosarcoma.

The present essay is aimed at getting the radiologist familiar with the basic histological skin structure, allowing for a better correlation with sonographic findings. A high-frequency (22 MHz) ultrasonography apparatus was utilized in the present study. The histological analysis was performed after the skin specimens fixation with formalin, inclusion in paraffin blocks and subsequent staining with hematoxylin-eosin. The authors present a literature review showing the relationship between sonographic and histological findings in normal cutaneous tissue, and discuss the technique for a better performance of the sonographic scan. High-frequency ultrasonography is an excellent tool for the diagnosis of different skin conditions. However, as this method is operator-dependent, it is crucial to understand the normal skin structure as well as the correlation between histological and sonographic findings.

The objective of this study was to create and evaluate a routine (macro) using Image-Pro Plus 4.5 software (Media Cybernetics, Silver Spring, USA) for automatic counting of labeled nuclei by proliferating cell nuclear antigen (PCNA) immunohistochemistry. A total of 154 digital color images were obtained from eleven sections of reticular oral lichen planus stained by PCNA immunohistochemistry. Mean density (gray-level), red density, green density, blue density, area, minor axis, perimeter rate and roundness were parameters used for PCNA labeled nuclei discrimination, followed by their outlined presentation and counting in each image by the macro. Mean density and area thresholds were automatically defined based, respectively, on mean density and mean area of PCNA labeled nuclei in the assessed image. The reference method consisted in visual counting of manually outlined labeled nuclei. Statistical analysis of macro results versus reference countings showed a very significant correlation (rs = 0.964, p < 0.001) for general results and a high level (89.8 +/- 3.8%) of correctly counted labeled nuclei. We conclude that the main parameters associated with a high correlation between macro and reference results were mean density (gray-level) and area thresholds based on image profiles; and that Image-Pro Plus 4.5 using a routine with automatic definition of mean density and area thresholds can be considered a valid alternative to visual counting of PCNA labeled nuclei.