Abstract
RATIONALE: Trichilemmal cyst (TC), also known as trichodermal cyst, trichodermal isthmus-degenerative cyst. It is a benign skin lesion originating from the outer hair root sheath, with low incidence and few reports. PATIENT CONCERNS: A 41-year-old patient had found a scalp lump for more than 10 years. A 2.0 cm × 1.0 cm × 1.0 cm lump on the right occipital region was touched more than 10 years ago without special treatment. In the past 2 years, the lump has gradually increased. Physical examination: 4 protruding lumps can be reached in the scalp. One lump in the right occipital region is about 3.0 cm × 2.0 cm × 2.0 cm, with 1 lump immediately below and 2 lumps in the left temporal region. All lumps can be pushed. DIAGNOSES: The lesion is located in dermis, The lesion is solid, and the contents of the cyst were cheese-like white material, and the inner and outer walls of the cyst were smooth and shiny. Pathological results showed that the lesion was TC. The cyst wall is epidermal tissue, the spinous layer and basal layer are intact, there is no granular layer, and the protein in the cyst is dense. INTERVENTIONS: All lumps were completely surgically removed. OUTCOMES: The wound healed well after TC resection. There was no recurrence of TC after 1 year follow-up. LESSONS: The clinical manifestations of scalp TC are not specific, and the diagnosis needs pathological examination, and the prognosis of total excision is good.