Lentigo maligna: Topical agent option for malignant melanoma -

Lentigo maligna: Topical agent option for malignant melanoma - - DermatologyTimes

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Lentigo maligna: Topical agent option for malignant melanoma

May 1, 2009
By: Cheryl Guttman
Supplement

Patients with invasive malignant melanoma surrounded by lentigo maligna
Dual therapy of limited surgical excision followed by topical application of imiquimod effective

San Francisco — Preliminary, yet promising, outcomes in two patients suggests dual therapy involving limited surgical excision followed by topical application of imiquimod 5 percent cream (Aldara, Graceway) may be an option to consider for treating invasive malignant melanoma surrounded by lentigo maligna (LM) in patients who refuse or are not good candidates for more extensive surgery, according to researchers from the department of dermatology, Saint Louis University School of Medicine, St. Louis.

Dr. Missall

At the annual meeting of the American Academy of Dermatology, Tricia A. Missall, M.D., Ph.D., dermatology resident, and Scott W. Fosko, M.D., chairman and professor of dermatology, presented a poster describing the cases of two patients who presented with extensive melanoma in situ, lentiginous type (LM), that included a focal area of invasive malignant melanoma. Surgical excision of the entire lesion would have resulted in a very large defect and both patients refused this intervention, Dr. Missall says.

STUDY DETAILS

Each patient was treated with imiquimod as adjunctive therapy. Surgical excision of the known invasive component was performed first, followed several weeks later with initiation of topical imiquimod. Follow-up biopsies showed the treatment resulted in histological clearance, and 19 to 21 months after the course of imiquimod was completed, both patients remained clinically clear.

Before: Large LM lesion on patient's scalp with focal invasive LMM. After: Patient free of disease after excision of LMM and topical imiquimod treatment of extensive surrounding LM. (Photos: Tricia Missall, M.D.)

"There have been several published articles describing the successful use of topical imiquimod treatment for LM alone or as an adjunct to surgery, and we have also used the topical immunomodulatory agent in this way with favorable results.

"Although the collective number of patients treated is limited, as is the duration of follow-up, this experience encouraged us to consider imiquimod in our patients with LM, including a focal invasive component, who may not opt for definitive surgery.

"To our knowledge, ours is the first report of such cases," Dr. Missall tells Dermatology Times.

"Data from more patients and from longer-term follow-up are needed to ultimately determine the role of topical imiquimod in the management of LM with and without an invasive component."

One of the patients treated with the dual therapy approach had one scalp lesion measuring nearly 8 cm by 8 cm, along with multiple other smaller scalp lesions. Multiple punch biopsies were obtained from the large lesion and revealed lentigo maligna melanoma (LMM) (Breslow depth 0.4 mm) at one site, while other specimens showed either LM or benign solar lentigo.

The invasive component was excised to the periosteum with 1 cm margins, and the defect was closed with a graft.

Topical imiquimod was started four weeks postsurgery, with the patient instructed to apply the cream to the entire lesion plus a 2 cm margin of normal-appearing skin.

Treatment was initiated five times a week and was continued for 14 weeks, although for four weeks, the frequency of application was reduced to three times a week to allow the patient to tolerate an intense inflammatory response.