Introduction
Primary cutaneous lymphomas are heterogeneous group of non-Hodgkin lymphomas with the origin of T- or B-cells and account for approximately 2% of all lymphomas. In tissue sections of B type lymphoblastic lymphoma (B-LBL), generally a diffused pattern of growth is noted [1,2]. B-LBL is always positive for B-cell markers CD19, CD79a, and CD22. CD10, CD24, PAX5, and terminal deoxytransferase (TdT) are expressed in most cases, while the expression of CD20 and CD34 is variable and CD45 may be absent [3]. The common criteria to differentiate lymphoblastic lymphoma (LBL) from acute lymphoblastic leukemia (ALL) are their manifestations as bulky masses in solid organs, and focal or absent bone marrow involvement. LBL presents with skin involvement more frequently. Furthermore, the incidence of central nervous system involvement in LBL is higher than ALL [4]. B-LBL is more frequently associated with skin or subcutaneous tissue involvement or bone lesions, while T-LBL predominantly shows mediastinal involvement. It usually occurs in early middle age, involves lymph nodes and extra-nodal sites, and usually doesn’t invade the bone marrow [5, 8]. Here, we report a case of cutaneous lymphoblastic lymphoma with the origin of B-cells presenting with solitary scalp mass.