Eruptive molluscum contagiosums in a patient with rheumatoid arthritis and lung cancer.

A 67-year-old woman with rheumatoid arthritis (RA) treated with systemic prednisolone and methotrexate over 20 years developed eruptive molluscum contagiosums on the trunk and extremities. Investigation revealed lung cancer 2 years later. Newly development of molluscum contagiosums ceased after the surgical operation of lung cancer. Immunologic dysfunctions have been shown in RA, and especially patients under long-term methotrexate therapy are susceptible to miscellaneous skin conditions. Eruptive molluscum contagiosums are induced in association with hematologic malignancies such as lymphoma, leukemia, and HIV infection; however, it is important to investigate internal malignancies, not only hematologic malignancies but also solid cancers, when patients with RA under immunosuppressive therapies presented eruptive or disseminated molluscum contagiosums.