Topical imiquimod 5% appears effective for periocular lentigo maligna

This small, retrospective case series evaluated the efficacy of topical imiquimod 5% for the treatment of periocular lentigo maligna. Lesions partially or completely resolved in all patients after a mean treatment duration of nine months, with no recurrences after a mean of 20 months. However, treatment was discontinued in two patients (one temporarily and the other permanently) because of discomfort, redness, swelling and cutaneous excoriation. The authors conclude that while periocular lentigo maligna seems to respond to topical imiquimod 5% cream, further study is needed.

Subjects in the study were five consecutive patients with biopsy-proven periocular lentigo maligna who were treated with only topical imiquimod 5% cream. The anatomic location of lentigo maligna was the medial canthal area in two patients, lateral canthal area in one patient and lower eyelid in two patients.

Three patients were treated with topical imiquimod 5% five days per week. The remaining patients were treated seven days a week, since they were compliant and tolerated the therapy well. During the first week, the cream was applied once daily at bedtime over the surface of the lentigo maligna and extended 10 mm outside the lesion. After that, it was applied weekly until resolution of the tumor. If the lesion was less than 5 mm from the eyelid margin, topical erythromycin was applied over the globe before placement of imiquimod ointment. Care was taken to ensure that imiquimod would not penetrate the ocular surface in order to avoid chemical burn. The medication was placed only on the skin and not on the globe. The most common side effects included localized erythema and discomfort in four patients, swelling in three patients and cutaneous excoriation in two. 

The function of this treatment is similar to mitomycin C and 5-fluorouracil, and probably other agents have similar or better efficiency with minimal or no side effects. Before topical imiquimod 5% becomes part of standard lentigo maligna therapy, a longer follow-up with more patients is required in order to gain more information about recurrence and side effects. Histologic specimens are necessary in order to demonstrate the eradication of this premalignant lesion. It is also important to determine whether it will be easy to detect early recurrence or if it might be atypical and difficult to diagnose. Additionally, an optimum treatment schedule and duration needs to be determined.