Low-grade B-cell lymphoma and concomitant extensive sarcoidlike granulomas: a case report and review of the literature.

Sarcoidlike granulomas may occur in association with Hodgkin lymphoma and non-Hodgkin lymphoma. The granulomas may be concomitant and so extensive that they obscure the malignant process. In addition, a sarcoidosis-lymphoma syndrome has been described in which there appears to be a relationship between sarcoidosis and the development of a lymphoproliferative disorder. We report a case of a low-grade B-cell lymphoma with concomitant extensive sarcoidlike granulomas. The patient had no diagnostic clinical evidence of sarcoidosis, although she had an elevated serum calcium level and increased serum angiotensin converting enzyme activity. Increased serum calcium and serum angiotensin-converting enzyme activity have been associated with clinical sarcoidosis but have also occasionally been described in association with Hodgkin lymphoma and non-Hodgkin lymphoma without evidence of sarcoidosis. We describe our findings and illustrate the usefulness of immunoperoxidase immunophenotyping techniques in such a case.

Extra-acral calcifying aponeurotic fibroma: a distinctive case with 23-year follow-up.

Calcifying aponeurotic fibroma (CAF) is an unusual but well-characterized soft tissue neoplasm that typically involves the digits of children and frequently recurs locally. This report describes a case from the subcutis of the lumbosacral region. A 26-year-old man initially presented at age 3 and developed three recurrences over a 23-year period each at approximately 8-year intervals (ages 10, 18, and 26). The microscopic findings in all recurrences showed a lobulated, poorly circumscribed proliferation of dense fibrous tissue containing epithelioid-like fibroblasts, multinucleated cells, and islands of metaplastic chondroid differentiation with focal calcification. Despite origin from an unusual anatomic site, this case reported herein demonstrates the classical morphologic features and clinical history of CAF which showed little in the way of morphologic evolution despite 23 years of persistence. The clinical and histologic features helpful in distinguishing CAF from infantile fibromatosis and soft tissue chondroma are discussed.

Tumor cells induced by the v-src oncogene are heterogeneous for expression of markers of mesenchyme differentiation.

The observation that v-src-induced tumors contain tumor cells of differing morphology, notably fibroblastoid or polygonal, raised the question as to whether the tumor cells are also heterogeneous with respect to expression of markers of cellular differentiation. Of the markers tested here, consistent reactivity for tumor tissue was noted only for antibody probes reactive to muscle actin (HHF35, alpha sm-1) or to procollagen type I (SP1. D8); for any given tumor, whether induced by v-src DNA or by Rous sarcoma virus, each of these markers was found only in a subpopulation of tumor cells. The observation of marker heterogeneity in the one v-src DNA-induced tumor examined here that typed as monoclonal suggests that v-src-induced transformation is consonant with a degree of plasticity in the phenotypes of the clonal progeny of a single transformant.

Induction of a diffuse mesothelioma in chickens by intraperitoneal inoculation of v-src DNA.

The presence of peritoneum-based, cytokeratin-positive tumor cells, as detected under conditions of intravenous inoculation of chickens with a v-src-positive DNA fragment, raised the possibility that such DNA may be inductive for diffuse mesothelioma. To investigate this possibility, chickens were inoculated intraperitoneally with v-src DNA, and the resultant peritoneum-based tumor tissue was subjected to histopathological analysis. On the basis of (i) morphology, (ii) immunohistochemistry/histochemistry, and (iii) ultrastructure, we concluded that this tissue represents a diffuse mesothelioma.