Conventional epidermal cysts are generally small, slow-growing, non-tender, dome-shaped lesions. An epidermal cyst is usually asymptomatic until it is infected or enlarged to the extent that it causes damage to adjacent anatomical structures. However, few cases of giant epidermal cysts in the neck have been reported. The present case reports a giant epidermal cyst in the posterior neck, which grew to an extremely large size for >40 years without inflammation or rupture, and was misdiagnosed as a large soft tissue neoplasm. The patient exhibited depression and developed social anxiety due to the negative cosmetic consequences of the large mass. The patient underwent excision of the mass. At the follow-up examination two years postoperatively, there were no local recurrence and the psychiatric symptoms of the patient were completely resolved. To the best of our knowledge, a giant epidermal cyst growing for >40 years has not previously been reported.

The purpose of this study was to analyze the results of treatment and prognosis of Marjolin's ulcer compared with primary squamous cell carcinoma. Materials and Methods: Fourteen patients treated for Marjolin's ulcer were analyzed. Twenty patients with primary squamous cell carcinoma treated during the same time period was the control group. Mean age was 61.2 years. There were 24 males and 10 females. The locations, TNM stages, histological grades, recurrence, metastasis, and survival rate were analyzed and compared between two groups. Results: The mean follow-up period was 54.8 months (range, 12-168 months). Local recurrences were found in 6 cases, 5 ones in Marjolin's ulcer patients, and one case in primary squamous cell carcinoma patients. The mean time interval between the initial presentation and occurrence of local recurrences was 9 months (range, 2-20 months). There were 6 metastases. 2 (14.3%) metastases were found in Marjolin's ulcer patients, and 4 (20.0%) metastases in primary squamous cell carcinoma patients. Total events (metastasis or local recurrence) were found in 10 pateients, 6 of them in Marjolin's ulcer group, and the remaining four in primary group. 5-year disease-free survival rate was 64.3% in Marjolin's ulcer group and 95.0% in primary squamous cell carcinoma group. Conclusion: Squamous cell carcinomas originating as Marjolin's ulcers revealed higher recurrence rate and lower survival rate despite of aggressive treatment. Therefore, new treatment modalities should be developed for improving outcomes.