Abstract
INTRODUCTION AND IMPORTANCE: Epidermal cysts can rarely occur in internal organs, but epidermal cyst of the urinary bladder is extremely rare with a very low tendency for malignant transformation. This article will guide the physicians to be aware of such rare complex neoplastic combinations to take proper decisions in management and treatment of the patients. CASE PRESENTATION: A 40-year-old rural male patient with hematuria and urinary frequency presented to a hospital. Ultrasonography reported a cyst and a 2 × 1.5 cm stone in the urinary bladder. Surgery planned to remove the cyst and the stone. During the surgery, a cyst with solid parts and a stone were observed. The cyst had superficial penetrations into the bladder wall, the patient refused to done radical cystectomy, therefore the cyst excised from the bladder and sent for histopathological examination. The histopathological examination confirmed a well differentiated invasive squamous cell carcinoma arising from epidermal cyst with detrusor muscle invasion, staged pT2aNx. After diagnosis the patient received chemotherapy and improved his urinary symptoms. The possibility of further radical cystectomy and radiotherapy in neighboring countries remains open. CLINICAL DISCUSSION: Urinary bladder cysts associated with stones are uncommon but the occurrence of epidermal cyst in the urinary bladder is an extremely unusual incidence and malignant transformation of this lesion made it even rarer. CONCLUSION: Despite the rarity of malignant transformation in epidermal cyst and the unknown etiology of its occurrence in the urinary bladder, further clinicopathological and molecular studies are needed to reveal the possible pathogenesis with involved risk factors.