CD4 and synovial sarcoma: Diagnosis is based on the clinical presentation, presence of SS cells in the skin, detection of clonally rearranged T-cell receptor (TCR) in both skin and peripheral blood, as well as on one or more aberrancies in the peripheral blood, such as an absolute count of > 1000 SS cells mm3, a CD4/CD8 ratio of > 10, and loss of T-cell markers such as CD2, CD3 and/or CD5 [2, 4].