Histiocytic sarcoma: a study of five cases including the histiocyte marker CD163

摘要: Histiocytic sarcoma (HS) is a rare but controversial hematopoietic neoplasm. In the past, malignancies have been misclassified as histiocytic tumors due to overlapping histologic features and inadequate phenotypic data. CD163, recently characterized hemoglobin scavenger receptor, appears be ‘specific’ marker of lineage promising diagnostic tool for evaluating neoplasms. Five cases HS were studied further elucidate clinicopathologic these demonstrate utility CD163. Criteria diagnosis included immunohistochemical evidence differentiation, CD45 positivity, exclusion lymphoid, epithelial, melanocytic dendritic cell phenotype. Sites disease colon (two cases), palate, inguinal lymph node, testis. The clinical course was aggressive in 4/5 patients (survival=2–15 months). One patient with localized survived 17 years after diagnosis. All poor survival had ≥3.5 cm. Histologically, all showed diffuse architecture large, discohesive polygonal cells. Spindling cells focally noted. Hemophagocytosis identified 3/5 cases. A prominent inflammatory background present tumors. immunoreactive CD45, CD68, lysozyme. S-100 positive Antibodies melanocytic, markers negative. Molecular studies monoclonal IgH gene rearrangements three Our findings suggest that an uncommon neoplasm frequently extranodal presentation behavior, exceptions. Stage possibly tumor size are significant prognostic indicators. remain morphologic relatively uniform; however, requires more common neoplasms by extensive immunophenotypic studies. CD163 specific important establishing HS.