Immune Checkpoint Markers in Superficial Angiosarcomas: PD-L1, PD-1, CD8, LAG-3, and Tumor-Infiltrating Lymphocytes.

ABSTRACT: Cutaneous angiosarcomas may express programmed death ligand-1 (PD-L1) and PD-L1 expression, and the presence of tumor-infiltrating lymphocytes (TILs) correlates with outcome. These observations provide a basis for PD-1/PD-L1 inhibitor therapy. Lymphocyte activation gene 3 (LAG-3) is an inhibitory receptor that interacts with the PD-L1 axis and is considered to be a marker of immune exhaustion. The presence of LAG-3-positive lymphocytes in cutaneous angiosarcoma has not been established. We reviewed 10 cases of treatment naive angiosarcoma of skin and superficial soft tissue and assessed for PD-L1 (ZR3) expression, presence of TILs, and expression of CD8, PD1, and LAG-3 by tumor-associated inflammatory cells by immunohistochemistry. All 10 angiosarcomas were positive for PD-L1: 7 with high expression and 3 with low expression. TILs were present in all tumors: brisk in 7 and nonbrisk in 3. CD8 lymphocytes were present in all tumors with a range of 212-1274 cells per square millimeter (mean 557 CD8 cells/mm2). LAG-3-positive lymphocytes were present in 9 of 10 angiosarcomas with a range of 0-728 cells/mm2 (mean 146 LAG-3 cells cells/mm2). The ratio of LAG-3 lymphocytes to CD8 lymphocytes was 0%-59% (mean 27%). The PD1 cell counts were intermediate between CD8 and LAG3 counts. Cutaneous angiosarcomas frequently express PD-L1, have prominent numbers of CD8 positive, and have smaller numbers of LAG-3-positive and PD-1-positive TILs. Our findings provide further evidence of PD-L1 expression in cutaneous angiosarcoma and the promise for immune checkpoint inhibitor therapy.

A case of bullous Sézary syndrome.

Sézary syndrome is a rare leukemic subtype of cutaneous T cell lymphoma that is characterized by erythroderma, lymphadenopathy, and malignant T cells in the peripheral blood. Poor prognostic factors of Sézary syndrome include advanced disease stage, older age at onset, and large cell transformation. Presentation with bullous lesions, though rare, has been reported in a few patients. We present an elderly woman with bullous Sézary syndrome who presented with a two-month history of progressive rash. Upon admission, the patient had pruritic, erythematous, edematous plaques with overlying flaccid bullae and erosions involving the scalp, neck, torso, and extremities. Despite treatment, the patient died two months after presentation. Although rare, bullous lesions associated with Sézary syndrome may indicate poor prognosis.