Infection by the guinea worm Dracunculus medinensis. The larvae are ingested
with contaminated water, penetrate the intestinal wall and deposit in connective tissue.
The worms mature in about one year and migrate to the subcutaneous tissue where an ulcer
may develop. The worm, if retained in the tissues, may calcify and typically has a coiled
appearance. The disease occurs in tropical Africa, India, the Far East and north South
America. Calcification is mainly seen in the legs