T-Cell Lymphoblastic Lymphoma with Cutaneous Involvement in a Child: A Rare Case Report.

T-cell lymphoblastic lymphoma (T-LBL) is a heterogeneous malignancy derived from T-cells that more commonly affects teens and males. Most commonly, T-LBL exhibits signs of lymph nodes, bone marrow, and mediastinal mass invasion, but in rare cases, the disease manifests cutaneously. We present a case of both cutaneous and systemic presentation of T-LBL in 9-year-old man in which the skin immunophenotype analysis showed TdT expression with positivity of CD3, CD4 and CD99. Review of all currently described cases of cutaneous T-LBL revealed that the most frequently positive tumor markers were TdT (100%), CD3 (100%), CD4 (59.1%) and CD99 (40.9%). Cutaneous involvement may be a prognostic factor in treating T-LBL with chemotherapy.