Noncutaneous Sites Research Articles

Prognosis following surgical excision of canine cutaneous mast cell tumors with histopathologically tumor-free versus nontumor-free margins: a retrospective study of 31 cases.

The purpose of this study was to determine if the presence of histopathologically tumor-free versus nontumor-free margins was prognostic for relapse or tumor-related death in dogs following surgical excision of single or multiple cutaneous mast cell tumors confined to the skin without evidence of metastasis to lymph nodes or other noncutaneous sites. Differences in tumor-related death or frequency of relapse between the two groups were not significant. Failure to achieve histopathological tumor-free margins frequently did not lead to local relapse. All tumor-related deaths occurred following local relapse. The lack of statistical support for an association between prognosis and histopathological tumor-free versus nontumor-free margins may be a result of small sample size.

Predominant Expression of CD44 Splice Variant v10 in Malignant and Reactive Human Skin Lymphocytes

The remarkable functional diversity of the cell surface receptor CD44 may be due to expression of multiple variant isoforms generated by alternative splicing of variant exons. Functional and correlative data implicate a role of CD44 variant isoforms in adhesion dependent processes such as lymphocyte recirculation and tumor progression and metastasis. We have analyzed 25 primary cutaneous lymphomas and 35 reactive lymphoid cell skin infiltrates or T cell-mediated skin diseases for the expression of CD44 variant isoforms. Irrespective of histologic typing, staging, and grading, cutaneous lymphomas as well as nonmalignant skin-infiltrating CD3+ CD4+ and CD8+ T and CD19+ B lymphocytes exhibited a strong expression of CD44v10 and a moderate expression of CD44v3 as determined by immunohistochemistry, immunofluorescence microscopy, and mRNA analysis. Expression of v5, v6, v7, and v9-containing CD44 variant isoforms was not detected. Furthermore, flow cytometry revealed expression of CD44v10 on a significant proportion of peripheral blood lymphocytes from Sézary's syndrome patients and a remarkable co-expression with cutaneous lymphocyte antigen. These results indicate a distinct CD44 variant isoform expression pattern associated with skin-homing lymphocytes different to lymphatic cells at noncutaneous sites. This differential expression pattern of CD44 variant isoforms may contribute to the development of lymphocyte skin infiltrates and/or the unique biologic behavior of cutaneous lymphomas.

Survival of patients with visceral metastatic melanoma from an occult primary lesion: A retrospective matched cohort study

Malignant melanoma presents as metastatic disease without an apparent primary in about 4% of cases. These are referred to as occult primary melanoma (OPM). It is not known whether these represent de novo malignant transformation in non-cutaneous sites or the disappearance of an unrecognised primary, perhaps on an immunological basis. We hypothesised that OPM might have a superior prognosis compared to patients with similar disease extent from a known primary lesion (KPM). We performed a retrospective cohort survival study of 146 patients with OPM and visceral metastases treated at the Sydney Melanoma Unit between 1983 and 1996. A control group of patients with KPM was matched for age, sex and site of visceral metastases. Survival was measured from the date of diagnosis of visceral metastases. Patients with OPM had a median survival of 233 days, significantly longer than the 176 days for those with KPM (P = 0.024; logrank test). Multivariate analysis allowing for simultaneous or prior involvement of lymph nodes, subcutaneous tissues or bone, and site of visceral involvement showed a significantly superior survival for OPM (hazard ratio (HR): 0.72; 95% confidence interval (CI): 0.55-0.93). A small part of the effect was explained by treatment, but models allowing for this still showed a significantly longer survival. Survival was longer in OPM patients. This may reflect an intrinsically superior host-tumour interaction.

Cutaneous epithelioid angiosarcoma: a clinicopathological study of four cases.

Four cases of cutaneous epithelioid angiosarcoma are described together with the potential diagnostic trap of mistaking these tumours for poorly differentiated carcinoma or malignant melanoma. The immunophenotypic profile using four endothelial markers showed positive staining in all cases for factor VIII related antigen in a predominantly paranuclear dot-like fashion and for CD31 (JC70); in three cases for CD34 (QB-END/10) and in two cases with UEA-1. All four cases were cytokeratin (CAM 5.2 and AE1/AE3) negative in contrast to the positive staining reported at non-cutaneous sites. Aberrant S-100 protein expression was seen in one case. In two cases subsequent recurrences showed better differentiation than the original tumour. Electronmicroscopy confirmed the absence of non-endothelial lines of differentiation but failed to reveal Weibel-Palade bodies.

Granuloma annulare in patients with malignant lymphoma: Clinicopathologic study of thirteen new cases

Reports of necrobiotic granulomas or granuloma annulare in patients with malignant lymphoma are rare. Our intent was to determine any unique clinical or histopathologic features in patients with granuloma annulare and lymphoma. We reviewed the medical records and biopsy material from 13 patients with granuloma annulare and lymphoma. Three patients had Hodgkin's disease and 10 had non-Hodgkin's lymphoma. The granuloma annulare lesions showed typical histopathologic features. However, the clinical pattern was frequently atypical, with painful lesions in unusual locations including the palms and soles. Three patients displayed granulomatous inflammation in noncutaneous sites, either within the malignant lymphoma or in uninvolved tissues, and all three had atypical clinical presentations of granuloma annulare. Granuloma annulare with atypical clinical presentations may be associated with an underlying hematopoietic malignancy and may be part of a generalized granulomatous reaction to malignant lymphoma.

ELAM-1 is an adhesion molecule for skin-homing T cells

Endothelial cell leukocyte adhesion molecule-1 (ELAM-1) has been described as an inducible endothelial cell-adhesion molecule for neutrophils, and is believed to have a key role in the extravasation of these cells at sites of acute inflammation. Here we report that ELAM-1-transfected COS cells also bind a unique skin-associated subset of circulating memory T cells defined by the expression of the cutaneous lymphocyte-associated antigen. T cells expressing this antigen bind at least as well as neutrophils to expressed ELAM-1, whereas other lymphocytes in the peripheral blood bind poorly, or not at all. Immunohistological survey of chronically inflamed tissue specimens revealed that vascular expression of ELAM-1 occurs at cutaneous sites in preference to noncutaneous sites. We conclude that at sites of chronic inflammation, ELAM-1 may function as a skin vascular addressin, a tissue-selective endothelial cell-adhesion molecule for skin-homing memory T lymphocytes.