WHAT IS A JUVENILE POLYP - AN ANALYSIS BASED ON 21 PATIENTS WITH SOLITARY AND MULTIPLE POLYPS

Background.-Juvenile polyps, the most common pediatric gastrointestina l polyp, have been typically characterized as either hamartomatous ove rgrowths or reactive inflammatory proliferations. Recent observations of excessive colonic and gastric carcinoma and dysplasia in juvenile p olyposis have prompted reclassification of this entity as a premaligna nt condition. The relationship between solitary or multiple juvenile p olyps and malignancy is less clear. Patients and Methods.-To further i nvestigate the frequency and significance of dysplasia in juvenile pol yps, we analyzed 28 polyps from 21 patients histologically and immunoh istochemically for substances previously associated with neoplastic tr ansformation in the colorectal adenoma-carcinoma sequence. Results.-Fi fteen patients had a solitary polyp, two had 2 to 9 polyps, and four h ad polyposis with 10 or more polyps. Most polyps exhibited inflammator y or regenerative atypia. Foci of dysplasia were noted in polyps from 11 patients, and immunoreactivity for p53 and human chorionic gonadotr opin was present in 12 of the 28 polyps each. These findings were all more frequent in the polyposis specimens than in solitary polyps. Conc lusions.-These observations, in combination with reports of an increas ed risk of carcinoma in juvenile polyposis, suggest that juvenile poly ps are lesions with a potential for neoplastic and malignant transform ation, although they share features of an inflammatory reactive proces s. The implications for clinical management of patients and pathologic evaluation of juvenile polyps warrant further investigation.