Figure A demonstrates a mucous cyst. This benign mass originates from the DIP joint, and is secondary to arthritis. It may be treated with aspiration or surgical excision. However, recurrence occurs frequently with aspiration. Debridement of any osteophytes from the DIP joint is crucial to preventing recurrence with surgical excision. Rizzo et al retrospectively evaluated the results of 154 mucous cysts treated with either aspiration or surgery. Aspiration resulted in a 40% recurrence rate. There were zero recurrences with surgical excision and joint debridement.
Rizzo M, Beckenbaugh RD. Treatment of mucous cysts of the fingers: review of 134 cases with minimum 2-year follow-up evaluation. J Hand Surg Am. 2003 May;28(3):519-24
PMID:12772114 (Link to Abstract)