Endoglin is Highly Expressed in Human Mast Cells.

Endoglin, known to be expressed in proliferating vessels, is of worth when evaluating microvessel density as a prognostic factor in many types of malignancies, including some subtypes of leukemia cells. In childhood acute lymphoblastic leukemia, endoglin is associated with adverse outcome. In bone marrow, endoglin identifies the repopulating hematopoietic stem cells. Mast cells are a component of normal tissue and play an important role in the regulation of several processes, including inflammation and neoplasia. The aim of this study was to evaluate the use of endoglin as a biological marker of mast cells compared with the gold standard stains. We studied 15 specimens of neurofibroma, 9 of mastocytosis, and 6 of fibrous scar tissue through immunohistochemistry (for endoglin and mast cell tryptase) and histochemical staining using toluidine blue. Quantitative analysis of the cells was performed by counting 5 hotspots. The validity of endoglin as a mast cell marker was assessed by intraclass correlation coefficient. The Kruskal-Wallis test was used to compare mast cell count for each marker. A strong endoglin expression was found in the cytoplasmic granules of mast cells within the 3 groups. Similar results were observed with mast cell tryptase as well as toluidine blue. The intraclass correlation coefficient revealed that endoglin is a highly reliable biomarker of mast cells when compared with mast cell tryptase and toluidine blue. In conclusion, endoglin may assist in the diagnosis and pathogenesis study of various processes associated with mast cells. An endoglin-neutralizing treatment for solid cancers and leukemia could also affect mastocytes and the immunologic system.

Peripheral giant cell granuloma associated with a dental implant: a case report and review of the literature.

The peripheral giant cell granuloma (PGCG) is a nonneoplastic lesion commonly caused by local irritation. This report describes a 46-year-old Caucasian male who presented with a PGCG associated with a dental implant. The dental implant was originally placed in August 2012. Ten months later, the patient presented with a well-circumscribed lesion associated with and covering the implant, at which time the lesion was excised. Four months later, due to recurrence of the lesion, a deeper and wider excisional biopsy with curettage of the adjacent bone was performed. No evidence of recurrence has been reported after 12 months of follow-up. Immunohistochemistry, using the antibody CD68, was performed to investigate the origin of the multinucleated giant cells, with their immunophenotype being similar to those of other giant cell lesions, including central giant cell granuloma, foreign-body reactions, and granulomatous reactions to infectious agents.

Fibrosarcoma originating in the mandible

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Fibrosarcoma is a malignant mesenchymal neoplasm of fibroblasts that rarely affects the oral cavity and can cause local recurrences or metastasis. In this article we describe a case of primary fibrosarcoma in the mandible in a 16-year-old girl. Microscopically the tumor showed an intense proliferation of spindle-shaped cells, varying little in size and shape and arranged in parallel bands, partly crossing each other, the mitotic activity was increased and there was nuclear pleomorphism. Immunohistochemically the cells only showed immunoreactivity for vimentin and negativity for S-100 protein, CD 68, cytokeratin cocktail, HMB-45, CD34, pan actin HHF 35, desmin, smooth muscle actin and epithelial membrane antigen (EMA). Based on clinical, radiological, histological and immunohistochemical findings the final diagnosis was high-grade intra-osseous fibrosarcoma. The treatment choice was radical surgery with mandibular reconstruction. After one year and nine months of the treatment the patient displayed multiple metastases. Radiation therapy and chemotherapy were used as adjuvant treatment. Unfortunately, the girl died two years after initial diagnosis