Lower lip recurrent keratoacanthoma: A case report

BACKGROUND: This paper introduces a case of recurrent keratoacanthoma (KA). KA is a self-healing disease. Recurrence after surgical resection is rare. In this case, the local application of retinoic acid ointment after the second operation achieved a good prognosis after 2 years of follow-up. CASE SUMMARY: A 76-year-old male patient was admitted to the hospital for "lower lip rupture and scab for 3 mo". Treatment: A rectangular incision was made in the healthy tissue about 3 mm outside the periphery of the lower lip mass, and a modified Bernard sliding flap was designed to completely remove the mass. Pathology showed (lower lip) KA. When the patient returned 6 mo after surgery, the middle mucosa of the lower lip had a bulge with a diameter of about 0.5 cm. The boundary was still clear, the surface was ulcerated. A recurrence of lower lip KA was suspected and a fan-shaped incision was performed in the healthy tissue about 5 mm outside the lesion to completely resect. Pathological showed lower lip KA had recurred. Topical application of tretinoin cream was applied once a day for 3 mo. The lower lip wounds were clean at the 2-year postoperative follow-up and the mucosa was normal. CONCLUSION: Adjuvant retinoic acid treatment after KA surgical resection can achieve good results.