Intralesional methotrexate for keratoacanthoma of the nose.

ABSTRACT

A 56-year-old woman developed a nodule on her nose. A shave biopsy of the enlarging lesion was performed after 2 weeks and showed a keratoacanthoma. During the subsequent 4 weeks, the lesion continued to grow rapidly, and she was referred for excision of the lesion using the Mohs microscopically controlled technique. A tender 10x12 mm (120 mm2) erythematous nodule with a keratin-filled central umbilication was present on her left nasal ala (Figure 1). Treatment options were discussed. The left nasal ala was locally anesthetized with 1% lidocaine with 1100,000 epinephrine and the keratoacanthoma was circumferentially infiltrated with 10 mg of methotrexate (0.8 mL of 12.5 mg/mL methotrexate) using a 30-gauge needle. The total amount of methotrexate injected was divided among several injection sites the peripheral shoulder of the lesion (such that there was blanching of the entire rim) and under the center of the lesion at a depth clinically judged to be the deepest area of involvement. Within the next 7 days, the tumor began to decrease in size and ulcerate centrally. Examination 2 weeks after the initial injection showed a 71% reduction in the area of the tumor, which now measured 35 mm2 (7.0x5.0 mm). The tumor was injected in a similar manner as before with 5 mg of methotrexate. After another 2 weeks, the tumor had continued to shrink. It was flat without nodularity and measured 12 mm2 (4.0x3.0 mm); the tumor area was 66% less than 2 weeks earlier and 90% less than its original size. The residual tumor was again injected with 4.5 mg of methotrexate. There was complete clinical involution of the tumor when the patient returned for evaluation 6 weeks after her initial injection of methotrexate (Figure 2). A biopsy of the lesional area to confirm histologic resolution of the keratoacanthoma was not performed since there was no visible residual tumor. Periodic follow-up examination has been performed and there has been no subsequent recurrence of the keratoacanthoma.