Malignancy and overdiagnosis of malignancy in Peutz Jeghers polyposis

Peutz Jeghers (PJ) polyps are rare hamartomatous tumors of the gastrointestinal tract frequently associated with skin and mucosal pigmentation. Despite their benign nature there is a certain increased risk of progression to malignancy in some cases, justifying a sustained follow-up of the patients. We present 3 cases of Peutz Jeghers syndrome (PJS) diagnosed in our hospital on gastrointestinal specimens obtained by endoscopy and opened surgery. We analyzed different degrees of dysplastic changes, epithelial intussusception, association with other types of polypoid lesions and other various aspects possibly related with disease progression. Clinico-pathological correlations were made. Two of these cases were related (mother and daughter); both of them were operated in another hospital for small bowel tumors with a subsequent diagnosis of adenocarcinoma. The daughter (28 years old) was referred to our hospital for endoscopic follow-up; a small polyp of the transverse large bowel was excised by colonoscopy with a histopathologic diagnosis of PJ polyp; a careful histopathologic reevaluation of both specimens of enterectomy (slides and paraffin blocks) revealed an overdiagnosis of cancer due to the epithelial cystic dilatation and pseudoinvasion in both patients. The other case showed diagnostic changes of PJS and also various aspects of adenomatous polyps some of them with mild and moderate dysplastic changes. When a PJ polyp is diagnosed, the possibility of pseudoinvasion should be kept in mind, in order to avoid overdiagnosis of malignancy; also, due to the fact that the malignant transformation of a PJ polyp is still on debate (hamartoma-dysplasia-carcinoma sequence versus malignant transformation of an adenomatous aria of a hamartoma versus coincidental association of a digestive cancer due to genetic aberrations of PJS), all the other associated microscopic aspects of the lesion should be carefully analyzed.