Low-dose Methotrexate Treatment for Solitary or Localized Primary Cutaneous Anaplastic Large Cell Lymphoma: A Long-term Follow-up Study.

Although low-dose methotrexate (MTX) has been used widely in treatment of a variety of dermatological diseases, including multifocal primary cutaneous anaplastic large cell lymphoma (PCALCL), it has not been established for use in the treatment guidelines for solitary or localized PCALCL. Furthermore, there has been no report of long-term follow-up data in Asian patients with PCALCL treated with low-dose MTX. To investigate the effectiveness and clinical outcome of treatment with low-dose MTX, clinical and long-term follow-up data of 7 patients with solitary or localized PCALCL were analysed retrospectively. Of the 7 patients, 6 (85.7%) showed a complete response and 1 (14.3%) showed partial remission. During follow-up, mean duration of 92.1 months, 5 patients developed one or more cutaneous relapses. At the last follow-up, all of the patients with PCALCL were alive without disease. These results indicate that low-dose MTX is a highly effective and safe treatment for solitary or localized PCALCL as well as multiple relapsed lesions.