A 74-year-old woman presents for treatment of a bothersome lesion on her thumb. She reports a history of arthritis. The lesion is frequently traumatized when doing housecleaning and cooking. A flesh-colored, semitranslucent nodule is noted between the proximal nailfold and the distal interphalangeal joint. No other fingers or toes are similarly affected.
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Digital myxoid cysts are the most common ungual tumor after warts.1 They have a female predominance and occur most commonly in middle-aged to elderly patients between the ages of 40 and 70 years. The etiology of myxoid cysts is unclear but is thought to involve mucoid degeneration of connective tissue. It may be seen in association with osteoarthritis and rheumatoid arthritis.2 In those who are younger than 30 years, trauma is often the precipitating factor.
Most digital myxoid cysts are readily diagnosed by clinical presentation. Lesions present on the dorsum of a finger as a translucent nodule located between the distal interphalangeal joint and the proximal nailfold.2 They tend to occur more frequently on the dominant hand, specifically on the middle and the first fingers.1,3,4 These cysts are typically asymptomatic, but patients may experience pain, tenderness, nail deformities, and decreased range of motion.1
When required, definitive diagnosis of myxoid cysts can be obtained by biopsy. MRI will distinguish myxoid cysts from other bony tumors, such as ganglion cysts. Asymptomatic digital myxoid cysts do not require therapy; smaller lesions may respond to daily compression during the course of several weeks.1,5 Some lesions spontaneously regress. Surgical excision with debridement of joint osteophytes may be curative but can eventuate in nail deformity when in proximity to the nail.1 Puncturing the cyst followed by pressure will extrude the cyst’s contents. Some lesions may involute following polidocanol sclerotherapy.6
Dr Schleicher is director of the DermDox Center for Dermatology, as well as an associate professor of medicine at the Commonwealth Medical College and a Clinical Instructor of dermatology at Arcadia University and Kings College.
- Li K, Barankin B. Digital mucous cysts. J Cutan Med Surg. 2010;14:199-206.
- Salerni G, Alonso C. Digital mucous cyst. N Engl J Med. 2012;366:1335.
- Mani-Sundaram D. Surgical correction of mucous cysts of the nail unit. Dermatol Surg. 2001;27:267-268.
- Kasdan ML, Stallings SP, Leis VM, Wolens D. Outcome of surgically treated mucous cysts of the hand. J Hand Surg Am. 1994;19:504-507.
- Wolff K, Johnson RA, eds. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. 6th ed. New York: McGraw-Hill; 2009.
- Esson GA, Holme SA. Treatment of 63 Subjects with digital mucous cysts with percutaneous sclerotherapy using polidocanol. Dermatol Surg. 2016;42:59-62.