Thursday, September 22, 2016

A case of recurrent ligneous conjunctivitis in an adult

Massive fibrin deposition in a case of recurrent ligneous conjunctivitis in an adult

I recently signed out a case of ligneous conjunctivitis, a rare form of chronic pseudomembranous conjunctivitis that is marked by a massive accumulation of fibrin. The term ligneous (from the Latin term for "woody") refers to the firm consistency of the large masses of fibrin that comprise the pseudomembranes. Ligneous conjunctivitis typically occurs in children but may recur in adults. Treatment is often challenging because the inflammation is persistent and the pseudomembranes often recur rapidly after excision. Histopathology shows two components: granulation tissue and sheets of intensely eosinophilic acellular amorphous material, which has been shown to be composed predominantly of fibrin. The mass of fibrin also incorporates other serum components such as immunoglobulin. Lesions that resemble those found in the conjunctiva can affect other mucous membranes including the larynx, vagina, and ear. Ligneous conjunctivitis is an autosomal recessive trait caused by mutations in the gene for plasminogen on chromosome 6q26.

Reference: Eagle, Ralph C. Eye Pathology: An Atlas and Text [2nd edition] page 55.


Scout said...

If I saw that slide, I would think of amyloidosis.

Brian E. Moore, MD, MEd said...

I definitely thought of that too, Scout. But after prior molecular diagnosis of plasminogen gene mutation (and a current negative Congo Red stain), the diagnosis of ligneous conjunctivitis was straightforward. Two days after getting this case, I received a specimen of conjunctival amyloidosis. I'll put up that case in a subsequent post. Cheers!