Myospherulosis

 

Features of myospherulosis:

(1) The patient has a history of application of a topical antibiotic within a petrolatum base, typically following surgery.

(2) The patient develop swelling, pain and/or drainage at the site.

(3) A biopsy shows a fibroinflammatory response and foreign body granulomatous reaction with cystlike spaces that contain yeast-like brownish spherules. The spherules are derived from transformed erythrocytes.

 

Sites where reported include:

(1) paranasal sinus

(2) oral or dental surgery

(3) bone

(4) soft tissue

 

Diagnosis involves exclusion of fungus by:

(1) negative fungal culture

(2) negative GMS stain for fungus

Rarely both myospherulosis and a fungal infection can coexist.