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.