Fas-ligand and caspase-3 positivity in three cases of histiocytic sarcoma: a different etiopathogenic pathway?

Abstract

Histiocytic sarcoma (HS) is a rare malignant neoplasia of hematopoietic origin and unknown etiology. We studied three patients with histiocytic sarcoma reviewing the morphological and immunohistochemical aspects. We evaluated in particular, if apoptosis may be unbalanced in this disease. All cases have morphological and immunohistochemical features consistent with the diagnosis of histiocytic sarcoma. The markers CD163, CD68, vimentin, lysozyme, and S-100 were positive in all cases. Similarly, the three samples were positive for Fas-ligand and Caspase-3. It is well-known that neoplasms may induce increased levels of Fas-ligand with the blockade of the apoptosis process. In the context of HS, the increased Fas-ligand expression represents a new area for research. Indeed, it is linked to proinflammatory stimulus and, maybe with the association of an infection.

Lymphocyte-depleted classic Hodgkin lymphoma with primary extranodal disease: Two cases that highlight the combination of immunodeficiency and immune escape in the pathogenesis

“…In general, EBV-positivity should prompt the suspicion of EBV-positive diffuse large B-cell lymphoma (DLBCL), not otherwise specified, particularly in patients with bulky extranodal disease. [6][7][8] DLBCL is similar to immunodeficiency-associated B-cell lymphoproliferative disorders, and it often displays a broad range of CHL-like morphologic features, which poses the diagnostic problem of differentiating DLBCL from CHL. 6,[9][10][11][12][13][14] We recently reported in a short series study that PD-L1 positivity is significantly lower in EBV+ tumors and non-malignant large B cells than in EBV+ CHL.…”

“…[6][7][8] DLBCL is similar to immunodeficiency-associated B-cell lymphoproliferative disorders, and it often displays a broad range of CHL-like morphologic features, which poses the diagnostic problem of differentiating DLBCL from CHL. 6,[9][10][11][12][13][14] We recently reported in a short series study that PD-L1 positivity is significantly lower in EBV+ tumors and non-malignant large B cells than in EBV+ CHL. Indeed, neoplastic PD-L1 expression was consistently detected in EBV+ CHL.…”