title: Attenuated polyposis of the large bowel: a morphologic and molecular approach.
abstract: Attenuated polyposis could be defined as a variant of familial adenomatous polyposis (FAP) in which synchronous polyps of the large bowel range between 10 and 99. We analysed all cases of attenuated polyposis observed over the last 30 years with the objectives: (A) to classify the disease according to different type and proportion of polyps; (B) To ascertain the contribution of APC and MutYH genes; (C) to discover features which could arise the suspicion of mutations; (D) To obtain indications for management and follow-up. 84 individuals in 82 families were studied. Polyps were classified into four groups as adenoma, hyperplastic, other serrated lesions or others; APC and MutYH mutations were assessed. Mean age at diagnosis was 54 ± 14 years in men and 48 ± 13 in women (P = 0.005). Polyps were more numerous in women (37 ± 26 vs 29 ± 22). Sixty % of patients underwent bowel resection, mainly for cancer; the remaining were managed through endoscopy. A total of 2586 polyps were detected at diagnostic endoscopy: 2026 (80 %) were removed and analysed. Adenomas were diagnosed in 1445 (70 %), hyperplastic polyps in 541 (26 %), other serrated lesions in 61 (2.9 %). Adenomas and hyperplastic lesions were detected in the majority of patients. In 68 patients (81 %) in whom studies were executed, APC mutations were found in 8 and MutYH mutations in 10. Genetic variants were more frequent in women (12 vs 6, P = 0.039). Taking into consideration the prevalent (>50 %) histology and presence of mutations, patients could be subdivided into four groups: (1) APC mutated polyposis (AFAP), when adenomas were >50 % and APC mutations detected (no. 8, 10 %); (2) MutYH mutated polyposis (MAP), adenomas >50 % and biallelic MutYH mutations (no. 10, 12 %); (1) attenuated polyposis without detectable mutations, prevalence of adenomas, 48 cases (57 %); (1) hyperplastic-serrated polyposis, with prevalence (>50 %) of hyperplastic/other serrated lesions and no constitutional mutation (no. 18, 21 %). Aggregation of tumors, cancer in probands, distribution of polyps and other clinical characteristics showed no difference among the four groups. In conclusions, AFAP and MAP, the polyposis labeled by constitutional mutations, represented about 25 % of all attenuated polyposis. Mutation-associated cases showed an earlier age of onset of polyps and were more frequent in the female sex.
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy. deleon@unimore.it.
authors: Maurizio Ponz
authors: MP
authors: de Leon
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Monica
authors: M
authors: Pedroni
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Luca
authors: L
authors: Roncucci
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Federica
authors: F
authors: Domati
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Giuseppina
authors: G
authors: Rossi
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Giulia
authors: G
authors: Magnani
authors: Medicina 1, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Annalisa
authors: A
authors: Pezzi
authors: Anatomia Patologica, Dipartimento di Medicina di Laboratorio, Ospedale Carlo Poma ASST, Mantua, Italy.
authors: Rossella
authors: R
authors: Fante
authors: Anatomia Patologica, Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia. Policlinico, Via del Pozzo 71, 41100, Modena, Italy.
authors: Luca Reggiani
authors: LR
authors: Bonetti
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000473:pathology*; D011125:Adenomatous Polyposis Coli / Q000235:genetics* / Q000473:pathology*; D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics*; D000328:Adult; D000367:Age Factors; D000368:Aged; D003113:Colonoscopy; D045647:DNA Glycosylases / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D017491:Genes, APC; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012737:Sex Factors
chemical_list: C555337:APC protein, human; D025601:Adenomatous Polyposis Coli Protein; D045647:DNA Glycosylases; C061738:mutY adenine glycosylase
keywords: AFAP; Adenoma; Cancer; FAP; Hyperplastic; Polyps; Serrated; Tumor