skin overlying the metastatic lesions. After August 2009 he continued
imiquimod as monotherapy to a larger area, including
both the anterior pelvis and the right upper quadrant. Surprisingly,
his metastatic lesions regressed, and one completely
disappeared. It is possible that application of imiquimod to a
larger area could have had an effect on the metastatic lesions.
While use of imiquimod for internal melanoma metastases has
not been reported, there is evidence that imiquimod is effective
for off-label treatment of cutaneous melanoma. A patient
presenting with multiple cutaneous and subcutaneous me
tastases on the scalp showed complete regression of lesions
after 17 months of topical imiquimod therapy.12 Another study
looked at seven patients with lentigo melanoma treated with
topical imiquimod for 12 weeks; at 19 months follow-up, six of
the seven patients showed both clinical and histologic resolution.
13 Of note, imiquimod is approved for treatment of actinic
keratoses, superficial basal cell carcinomas, and external genital
warts. Actinic keratoses are treated twice a day for no more
than 16 weeks, superficial basal cell carcinomas are treated five
times a week for six weeks, and genital warts are treated three
times a week for no more than 16 weeks. The cream is to be applied
in a thin layer and left on for eight hours before washing it
off.14 Use of imiquimod in cutaneous melanoma is off-label and
not supported by the manufacturers. The patient we report followed
an alternating two week application schedule that used
significantly more than the amount recommended for superficial
basal cell carcinoma. He used two full packets, one on the
abdomen and one on the pelvis, three times per week, for a
total of six packets in the first week. This typically caused sufficient
discomfort that he would use half of a packet on each area
three times per week, for a total of three packets in the second
week. He used this alternating schedule for nearly the entire
treatment course, and continues to do so.
In contrast to the multiple common and potentially serious
side effects of systemic chemotherapy, the only common adverse
effect of topical imiquimod is skin breakdown at the
application site.3 This patient experienced some skin breakdown,
but persisted with treatment. Although imiquimod has
only been indicated for the use of cutaneous diseases, this
report supports further exploration of the potential for topical
imiquimod or other topical therapies to play a role in treating
systemic disease. This may be useful for those who cannot
None of the authors have any relevant conflicts of interest, financial
- Lacarrubba F, et al. Advances in the use of topical imiquimod to
treat dermatologic disorders. The Clin Risk Manag. 2008;4:87-97.
- Miller RL, et al. Imiquimod applied topically: A novel immune response
modifier and a new class of drug. Int J Immunopharmacol. 1999;21(1):1-14.
- Sauder DN. Imiquimod: Modes of action. British Journal of Dermatology. 2003;149(Suppl 66):5-8.
- American Society of Health-System Pharmacists. Imiquimod Topical. AHFS Consumer Medication Information. 2009.
- Atkins MB, Lotze MT, Dutcher JP, et al. High-dose recombinant interleukin
2 therapy for patients with metastatic melanoma: Analysis of 270 patients treated between 1985 and 1993, J Clin Oncol. 1999;17:2105–2116.