Epithelioid Cell Component Research Articles

Sequential changes in cadherin‐catenin expression associated with the progression and heterogeneity of primary oesophageal squamous carcinoma

Maintenance of an adhesive function for cadherins requires appropriate membranous cellular expression and intact cadherin–catenin complexes. In normal squamous mucosa of the oesophagus there is membranous co-expression of E- and P-cadherin (E-cad, P-cad) in the basal compartment, whereas suprabasal stratification is associated with preservation of E-cad expression but loss of P-cad. Immunohistochemical staining of squamous dysplasia/carcinoma in situ shows a striking increase in the proportion of cells within the epithelial compartment showing co-expression of E- and P-cad with strong appropriate membranous expression of β and γ catenin. Strong membranous co-expression of E- and P-cad and β catenin is seen on keratinocytes at the periphery of islands of invasive better-differentiated squamous carcinoma with keratinisation, mimicking normal mucosa. β Catenin may be phosphorylated with implied loss of cadherin binding. Membranous cadherin and catenin expression is significantly down-regulated in poorly differentiated squamous carcinoma. No β catenin mutations were demonstrated in squamous carcinomas following DNA extraction and sequencing, nor was any nuclear cadherin seen. Changes in cadherin–catenin complexes with cellular phenotype is well demonstrated in spindle cell carcinomas with a shift of cadherin expression from membranous to cytoplasmic between the epithelioid and spindle cell components of the tumour and with loss of expression in the sarcomatoid elements. In conclusion, we demonstrate an increased expression of P-cadherin early in tumourigenesis with loss of cadherin–catenin complexes in poorly differentiated invasive carcinomas. Cadherin/catenin expression may govern both the phenotype and biology of oesophageal squamous carcinomas. Int. J. Cancer (Pred. Oncol.) 79:573–579, 1998. © 1998 Wiley-Liss, Inc.

Endoluminal Sonographic Evaluation of Ureteral and Renal Pelvic Neoplasms

Endoluminal Sonographic Evaluation of Ureteral and Renal Pelvic Neoplasms

Spitz naevus with a predominant epithelioid cell component and halo reaction

Spitz naevus with a predominant epithelioid cell component and halo reaction

Cutaneous melanoma: pathology, relevant prognostic indicators and progression.

Malignant melanoma, one of the most rapidly increasing malignancies in man, has recently received substantial attention in the world literature concerning application of traditional morphologic and newer immunologic and molecular biologic methods of predicting progression and ultimate clinical outcome. Although clinical features of patient sex, age and anatomic site of the lesion are important, classic morphologic variables defining prognosis remain the cornerstone of predicting disease outcome. Extent of radial growth phase and the two microstaging methods of measuring tumor thickness and determining level of invasion remain the critical disease progression predictors. Assessment of mitotic rate, number of tumor infiltrating lymphocytes, and determining the presence of regression, ulceration, and epithelioid cell component, microscopic satellites and vascular invasion are also important. More recently a variety of molecular and biochemical prognostic markers have been cited for prediction of disease recurrence and metastasis. Both overexpression and down regulation of a variety of cell adhesion molecules have been implicated in disease progression as has alterations in the plasminogen activation system. A series of growth factors, growth factor receptors, oncogenes and tumor suppressor genes have also been considered. Structural and numerical genomic DNA abnormalities, cell proliferation markers and DNA ploidy status have also been considered. Recently a variety of serum and blood markers indicating disease persistence or progression have been studied including melanin synthesis precursors and intermediate compounds of melanogenesis. Molecular detection by PCR of melanogenesis specific mRNA may become the most sensitive prognostic marker of the future. At present histopathologic and clinical criteria remain the cornerstones of predicting prognosis in malignant melanoma.

Melanocytic nevi with focal atypical epithelioid cell components: A review of seventy-three cases

We report a variant of melanocytic nevus that may be confused with melanoma. The purpose of this study is to describe the clinical, histologic, and biologic features of nevi with focal atypical epithelioid cell components (clonal nevi). Seventy-three cases were retrieved by reviewing lesions previously diagnosed as clonal, combined, deep penetrating, and inverted type-A nevi. Histologic features were assessed and referring physicians received a questionnaire about the presentation and outcome of each case. Histologically, all cases had a biphasic pattern characterized by an ordinary nevus that contained a darkly pigmented collection of large distinct epithelioid melanocytes in the superficial dermis. Immunostains identified mutant p53 proteins in 50% of dermal clones (9 of 18) but not in ordinary nevus cells adjacent to the clones. We are not aware of any patient developing a malignant melanoma (mean follow-up 24.5 months), including 41 cases that were initially incompletely excised. Clonal nevi are a distinct variant of melanocytic nevi and should be distinguished from malignant melanoma arising in a preexisting nevus.

Histological and Immunohistological Findings in Lymphoepithelioid Cell Lymphoma (Lennertʼs Lymphoma)

Four hundred and two cases considered or suspected to be lymphoepithelioid cell lymphoma (Lennert's lymphoma) were analyzed morphologically, immunohistochemically, and clinically. One hundred and eight of these cases, investigated in 180 biopsies, fulfilled the morphological and immunohistochemical criteria for lymphoepithelioid cell lymphoma and are herein reported. Cellular composition and histological structure are described in detail as a basis for discriminating Lennert's lymphoma from similar lymphomas with a high content of epithelioid cells (Hodgkin's disease, AILD type of T-cell lymphoma, lymphoplasmacytic lymphoma) and from inflammatory epithelioid cell reactions. Single typical Hodgkin cells were found in only 3.8% of biopsy specimens examined, and single typical Sternberg-Reed cells were found in only 2.2% of the biopsy specimens examined. Because these single Hodgkin and Sternberg-Reed cells were situated in a relatively monotonous lymphoid cellular pattern and because both these cells types also may occur in peripheral T-cell lymphomas, we include cases with such cells in the category of Lennert's lymphoma. Eight percent of the patients with lymphoepithelioid cell lymphoma showed transformation into a large-cell T-cell lymphoma without the prominent focal epithelioid cell component previously observed. Immunohistochemically, seven of the 69 biopsy specimens with detectable giant cells stained positively for the granulocyte-specific monoclonal antibody 3C4 (approximately CD15). Plasma cells were rare and always showed a polytypic immunoglobulin pattern. Lymphoepithelioid cell lymphoma, defined as a lymphoma of CD4+ T lymphocytes, marks the border between Hodgkin's disease and the non-Hodgkin's lymphomas. Today, absolute criteria for distinguishing between these two classes of lymphoma are lacking.

Malignant lymphoma with a high content of epithelioid histiocytes.A distinct clinicopathologic entity and a form of so-called „Lennert's Lymphoma”

Detailed pathologic and clinical findings in 19 patients with malignant lymphoma with a high content of epithelioid histiocytes (MLEH) are presented. The essential morphologic features for inclusion in this study comprised a diffuse architectural pattern; obliteration of normal nodal architecture; small, poorly defined clusters of epithelioid cells scattered throughout the stroma; and proliferation of atypical small and large lymphoid cells in varying proportions. Males predominated and the patients' ages ranged from 23 to 75 years, with a median age of 49 years. All patients had cervical adenopathy. Generalized adenopathy and splenomegaly occurred in approximately half. Hepatomegaly was less frequent, but the liver was histologically involved in four of seven patients in whom biopsies were performed. Skin rashes developed in two, but Waldeyer's ring involvement was noted in only one patient. More than half of these patients had „B” symptoms. Staging procedures disclosed that 74% were pathologic Stage IV. In seven surgically staged patients, the histologic features in the initial diagnostic lymph node biopsy were reproduced in the involved tissues at laparotomy. All patients received a variety of single agent and/or combination chemotherapy. Four patients received radiotherapy in addition to chemotherapy. The median survival was 15.6 months. Thirteen patients have died, all with clinical evidence of residual lymphoma. The cause of death in six was infection. In two of the four autopsies, the epithelioid cell component was absent and the microscopic features were indistinguishable from diffuse lymphoma of mixed cell type. While this disorder shares certain clinical and histologic features with Hodgkin's disease and with angioimmunoblastic lymphadenopathy, our observations lead us to the conclusion that MLEH, as defined in this paper, should be considered a variant of a non-Hodgkin's lymphoma and a distinct clinicopathologic entity.