A review of the clinical, radiologic, and histologic features of 25 cases of long bone adamantinoma is presented. To answer some questions concerning the nature of these tumors, relevant tissue markers were analyzed in seven cases using immunohistochemical assays. This study confirmed the epithelial nature of long bone adamantinomas irrespective of their wide-ranging morphologic patterns that can mimic tumors of various origin. On the basis of distinct radiologic, histologic, and immunohistochemical patterns, a new type of adamantinoma termed "differentiated adamantinoma" could be distinguished from the classic long bone adamantinomas. The diagnostic features characteristic of the differentiated adamantinoma include: patient age (first two decades), intracortical location of the entire lesion, uniform predominance of an osteofibrous dysplasia-like pattern, and scattered positivity of epithelial elements for cytokeratin. We postulate that the predominance of an osteofibrous dysplasia-like pattern in differentiated adamantinoma is the result of a secondary reparative process overgrowing matured and regressing tumor tissue. It is possible that this process may lead to the total elimination of recognizable tumor cells from the lesion. Therefore, osteofibrous dysplasia (ossifying fibroma) of long bones, which has a similar anatomic location, age distribution, and radiologic appearance as differentiated adamantinoma, may, in some cases, represent the evolution of an underlying adamantinoma. Our analysis suggests that long bone adamantinoma could be another member of the unique family of tumors that may regress spontaneously.
The neostriatum of 7 autopsied patients with Huntington's disease (HD) was examined immunohistochemically using purified antibody against calcineurin, which may be present only in the medium-size spinous neurons of the mammalian striatum. This study revealed a marked loss of calcineurin-positive cells in the caudate nucleus and the putamen in all HD patients, compared with control subjects, and there was some variation among the HD patients. Four HD patients showed significantly lower density of calcineurin-positive cells in the caudate nucleus than in the putamen. The remaining calcineurin-positive cells in the caudate nucleus and the putamen had a mosaic-like pattern, demonstrating a subregional difference in distribution. This finding suggests that there are subregional as well as compartmental differences in the vulnerability of the calcineurin-positive cells in the striatum of patients with HD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.