Primary cutaneous lymphoblastic lymphoma presenting in an 8-week old infant

Background: We report a case of primary cutaneous lymphoblastic lymphoma (LBL) presenting in an 8-week-old infant. Methods: Histopathology and flow cytometric analysis confirmed the diagnosis of a lymphoblastic lymphoma. The cells expressed CD 19, CD20, CD34 and surface inurumoglobulin (sIg). Results: The cells were negative for TdT and CD99. This unusual immunophenotype has been described as "transitional pre-B-cell", in that the cells express both immature markers (CD34) and mature markers (sIg). Conclusions: To our knowledge, only five other cases of sIg positive precursor B-cell LBL have been reported in the literature. This may represent the youngest reported case of primary cutaneous LBL, occurring at 8 weeks of age.