Repeated recurrent epidermoid cyst with atypical hyperplasia: A case report and literature review

RATIONALE: Epidermoid cysts are slow-growing, benign tumor which account for less than 1% of all intraspinal tumors and epidermoid cyst with Atypical Hyperplasia is very rare. Surgical resection is the standard treatment of the tumor, but recurrence is not uncommon after incomplete resection. Inappropriate treatment can lead to repeated recurrent. Here, we reported a case of repeated recurrent epidermoid cyst with atypical hyperplasia treated with radiotherapy after surgery. PRESENTING CONCERNS: A 40-year-old female presenting with intraspinal epidermoid cyst showed incomplete paraplegia in lower limbs. DIAGNOSIS: Back pain reappeared 19 months later after surgical treatment. The patient suffered marked weakness in both limbs, along with obvious muscle atrophy and sensation deficiency of warmth and pain in left lower limb. MRI demonstrated a cystic mass with solid content and peripheral strengthen in enhanced scan. INTERVENTIONS: Extended excision with intraoperative local chemotherapy and postoperative radiotherapy was performed and a dramatic reversal of symptoms was gained 4 weeks after surgery, with a total dose of 46 Gy. Postoperative pathological examination revealed epidermoid cyst with mild to moderate atypical hyperplasia. OUTCOMES: No acute side effects of the treatment were reported. Back pain obviously alleviated within 48 hours after surgery, while weakness and numbness of the lower limbs gradually improved and nearly disappeared in the 3-monthly follow-up visit. Until now, no recurrence is found during the 5-years follow-up. LESSONS: Our study highlights that incomplete excision has led to repeated recurrent epidermoid cyst, but its complete removal with adjuvant radiotherapy has achieved remission of symptoms. Atypical hyperplasia discovered by pathological examination reminds us the possibility of malignant transformation and ensures the necessity of adequate treatment.