Unusual localization of digit mucous cyst: fingertip = Unusual localization of digit mucous cyst: fingertip

다국어 초록 (Multilingual Abstract)

Digit Mucous Cyst(DMC) is a common condition that is clinically characterized by a round to oval, translucent, smooth nodule. Etiologically, the cyst might rise de novo by fibroblast overproduction of hyaluronic acid. The buildup of mucopolysaccharides pushes the collagen of the dermis upward, forming a pseudocyst. Such pathogenesis is independent from adjacent joint and is considered as a focal cutaneous mucinosis. In addition, a direct connection from an osteoarthritic joint might allow joint fluid to escape and form a mucous cyst. DMC typically involves the lateral or dorsal surfaces of the distal interphalangeal joint or over the proximal nail fold. It is occasionally painful and uncomfortable. Histologically, they are more accurately classified as pseudocysts because there is no epithelial lining of the spaces. Within the stroma, multiple small, cleft-like spaces with a tendency for liquefaction and cavity formation coalesce to form large cystic spaces containing mucin. A 57-year-old male, construction worker patient had a hyperkeratotic corn-like nodule over the tip of his right middle finger for 1 year. Tenderness of the nodule made the patient uncomfortable which eventually made the nodule removed. Shaving biopsy and curettage was performed and mucinous material was drained. Histological examination had revealed characteristic features of a mucinous cyst. Interestingly, the cyst was on the fingertip, a very unusual localization.