Also known as: digital myxoid pseudocyst, digital synovial cyst.

Clinical Features:

• Dome-shaped papule or nodule on the dorsal proximal nail fold or over an interphalangeal joint
• Contains viscous mucoid material

Histologic Features:

• Cystic mucin-containing spaces devoid of a lining epithelium (hence a "pseudocyst") within the dermis
• The cystic spaces begin as dermal clefts between collagen bundles and later coalesce to forms a single cystic space.
• The pseudocysts may occasionally have a synovial lining or a fibrous pseudocapsule.
• There is sometimes hyperplasia of the overlying epidermis.

Cases associated with this book:

Digital mucous cyst
Author: Artur Zembowicz M.D. Ph.D.

Conference: DermatopathologyConsultations.com Teaching Collection