Treatment Options for Primary Cutaneous Lymphoma?
A 76-year-old woman presented with erythematous cutaneous nodules over the scalp. Skin biopsy confirmed a diagnosis of large B-cell lymphoma. CT scans revealed no adenopathy or splenomegaly, "B" symptoms are not present, and bilateral bone marrow biopsies show no evidence of lymphoma. Is radiation alone appropriate or should systemic treatment be offered?

Of the extralymphatic sites of lymphoma, primary cutaneous lymphoma is quite common, second only to gastrointestinal primary lymphomas. Most primary cutaneous lymphomas consist of T cells, and their prognosis depends upon the exact type (ie, mycosis fungoides, anaplastic T-cell lymphoma, adult T-cell lymphoma/leukemia).

This patient had large B-cell lymphoma confined to the scalp. It is now agreed that these lymphomas should be distinguished from nodal B-cell non-Hodgkin's lymphomas. They are subclassified into primary cutaneous follicle center lymphomas, characterized by firm indurated scalp lesions (most likely the lymphoma affecting this patient), large-cell lymphoma of the leg (which is typically found in older individuals), and plasmacytomas. Once diagnosed, 25% of these patients are found to have systemic involvement (bone marrow, lung, liver), which was not found in the patient.

Treatment can be delivered with local radiotherapy (30-40 Gy) or chemotherapy. In a study comparing these modalities, 40 patients received radiotherapy alone; all achieved complete remission, 8 relapsed, and 3 died of lymphoma. Most of those who relapsed and all of those who died presented with lymphoma on the skin of the leg; none of the 12 patients with scalp lymphoma relapsed following radiation. Fifteen other cases were treated with chemotherapy: 2 of 11 who were treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) relapsed, vs all 4 treated with COP.

These data indicate that lesions that can be encompassed within a radiation field should be treated with radiation alone, while patients with multiple lesions that involve distant anatomical parts should be treated with doxorubicin-containing chemotherapy.