Three cases of inter-sterno-costo-clavicular ossification associated with tonsillar infection.

Three cases of inter-sterno-costo-clavicular ossification (ISCCO) associated with chronic tonsillitis are reported. Two cases had additional symptoms of pustulosis palmaris et plantaris (PPP). All the patients underwent tonsillectomy. The histological changes of the palatine tonsils of case 1 and case 2 were characterized by so-called focal small lacunar ulcers and periarteriolar fibrosis (onion-skin lesion). Some multinucleated giant cells were observed in case 2. Following tonsillectomy, symptoms in the clavicular region and the PPP improved. It is possible to consider that ISCCO is caused by focal tonsillar infection.