ABSTRACT
CONTEXT: Kaposi sarcoma (KS) is a vascular tumor frequently associated with advanced human immunodeficiency virus infection, advanced age, or iatrogenic immunosuppression. Immunohistochemistry for CD31 and CD34, and more recently for FLI1 and D2-40, has been used as ancillary diagnostic tests for KS, despite little information regarding the sensitivities and differential staining patterns of the latter 2 markers in the major clinical subtypes and histologic stages of KS. OBJECTIVE: This retrospective study aims to assess the prevalence of the vascular markers D2-40 and FLI1 in the main clinical subgroups and tumor stages of KS. DESIGN: Twenty-four cases of KS (12 acquired immunodeficiency syndrome [AIDS]-related cases and 12 non-AIDS-related cases; 11 nodular-stage and 13 patch/plaque-stage KS) were stained for CD34, CD31, D2-40, and FLI1 by immunohistochemistry. The distribution of immunoreactivity was compared between the clinical subtypes and tumor stages of KS using the Mann-Whitney test. RESULTS: CD31, CD34, D2-40, and FLI1 strongly and diffusely stained tumor cells in 75%, 92%, 67%, and 92% of AIDS-related cases and 58%, 92%, 67%, and 75% of non-AIDS-related cases, respectively. Differences in the proportions of positive cases between AIDS-related and non-AIDS-related cases did not reach statistical significance. No significant staining differences were observed between nodular- and patch/plaque-stage KS either. CONCLUSIONS: There are no differences in the distribution of immunohistochemical reactivity for CD31, CD34, D2-40, or FLI1 between AIDS-related and non-AIDS-related KS or between nodular- and patch/plaque-stage KS. All of the markers studied demonstrated high sensitivity in both clinical settings and both stages of tumor progression.
Subject(s)
Antibodies, Monoclonal, Murine-Derived/analysis , Antigens, CD34/analysis , Platelet Endothelial Cell Adhesion Molecule-1/analysis , Proto-Oncogene Protein c-fli-1/analysis , Sarcoma, Kaposi/diagnosis , Staining and Labeling/methods , Acquired Immunodeficiency Syndrome/complications , Biomarkers, Tumor/analysis , Diagnosis, Differential , Disease Progression , Humans , Immunohistochemistry/methods , Neoplasm Staging , Reproducibility of Results , Retrospective Studies , Sarcoma, Kaposi/complications , Sarcoma, Kaposi/metabolism , Sensitivity and SpecificityABSTRACT
CONTEXT: Infection is a common cause of lymphadenopathy in children and has numerous microbial etiologies. Lymph node biopsy is considered a keystone in arriving at a definite diagnosis. An accurate differential diagnosis from a lymph node biopsy can expedite diagnosis and minimize ancillary testing. OBJECTIVE: To assess and compare the histopathologic and epidemiologic features of common and uncommon pediatric bacterial lymphadenitis. DESIGN: We searched our database for surgical specimens that had a positive identification of bacteria during an 8-year period. The chart was reviewed to assess the pathogen identified and epidemiologic data. The archival tissue sections were reviewed and the histopathologic findings described for each pathogen. RESULTS: The review of 368 pediatric lymph node biopsies identified 33 cases with a bacterial infection. These comprised 21 cases of Mycobacterium avium complex (60%), 1 of Mycobacterium fortuitum (3%), 7 of Bartonella henselae (20%), 2 of Yersinia enterocolitica (7%), 1 of Francisella tularensis (3%) and 1 of Streptococcus pyogenes (3%). CONCLUSIONS: Each of these infectious lymphadenitides had distinct epidemiologic and histopathologic features that are discussed in this report.
