Case 74 - Discussion

Uploaded: 2007-11-30, Updated: 2007-12-01

Digital Mucous Cyst

• Digital mucous cysts are benign ganglion cysts of the digits, typically located at the distal interphalangeal (DIP) joints or in the proximal nail fold. They usually occur on the hands, although they have also been noted on the toes. The etiology of these cysts is uncertain but may involve mucoid degeneration. Often, these cysts are asymptomatic and do not require treatment;
• On microscopy, a pseudocyst with a fibrous capsule and myxomatous stroma with scattered fibroblasts is seen. A partial mesothelial lining, but not a true cyst wall, may be found. The overlying surface epithelium demonstrates compact hyperkeratosis with a collarette of hyperplastic epidermis. The mucinous contents stain basophilic with hematoxylin and eosin and can be seen clearly when stained for acid mucopolysaccharides with colloidal iron or Alcian blue

• http://www.emedicine.com/derm/topic100.htm