Expression of TOX in mycosis fungoides and its diagnostic value

Objective To assess the value of thymocyte selection-associated high mobility group box (TOX) protein in the diagnosis of mycosis fungoides (MF) . Methods Totally, 63 paraffin-embedded tissue specimens were collected from Department of Pathology, West China Hospital, Sichuan University between 2003 and 2016, including 30 specimens of suspected MF, 23 specimens of confirmed MF and 10 specimens of benign inflammatory dermatoses. Immunohistochemical staining was performed to compare the expression of TOX among groups. Results Twenty-six (86.7%) suspected MF specimens were positive for TOX, 20 (87%) confirmed MF specimens, and 3 (30%) benign inflammatory dermatosis specimens were positive for TOX. The positive rate of TOX protein was significantly higher in the suspected MF group and MF group than in the benign inflammatory dermatosis group (both P<0.05) . Conclusions TOX protein was expressed to different extents in the cases of suspected or confirmed MF, and its positive rate was markedly higher in the suspected or confirmed MF group than in the benign inflammatory dermatosis group. TOX protein may act as one of molecular markers for MF. Key words: Lymphoma, T-cell; Diagnosis; Mycosis fungoides; Thymocyte selection-associated high mobility group box protein