Case report
A 5-year-old previously healthy boy presented to our dermatology department with a 2-month history of skin tumor on his scalp associated with cervical nodes. On physical examination, there was a 4 cm, dome-shaped, firm, tender, erythematous tumor of the left parietal region of the scalp (figure 1). It was associated with multiple, bilateral, asymmetric cervical nodes. Blood cell count showed normal values for blood cell count and platelet count. Skin biopsy of the scalp lesion showed a diffuse infiltrate of atypical lymphoid cells in the entire dermis (figure 2A). The neoplastic lymphoid cells appeared medium-sized with inconspicuous nucleoli, scant cytoplasm, and a high mitotic rate (figure 2B). A grenz zone was present below a normal-appearing epidermis. Immunohistochemical (IHC) studies revealed that neoplastic cells expressed terminal deoxynucleotidyl transferase (TdT) (figure 2C), CD10, CD34, CD79a, and Bcl2, but were negative for CD3, and CD20. Peripheral blood and bone marrow aspiration smear, cerebrospinal fluid analysis revealed no evidence of any neoplastic populations. Whole-body computed tomography revealed involvement of the cervical, axillary and mesenteric lymph nodes associated with hepatomegaly. Based on these findings a diagnosis of primary cutaneous precursor B-cell lymphoblastic lymphoma was made. The patient was treated with polychemotherapy GFAL B2001 protocol including 6 courses of vincristine, oncovin, methotrexate, and prednisone. He showed partial remission after a 14-month follow-up.