title: PDGFRA-mutant syndrome.
abstract: Germline PDGFRA mutations cause multiple heterogeneous gastrointestinal mesenchymal tumors. In its familial form this disease, which was formerly termed intestinal neurofibromatosis/neurofibromatosis 3b (INF/NF3b), has been included among familial gastrointestinal stromal tumors (GISTs) because of its genotype, described when GIST was the only known PDGFRA-mutant gastrointestinal tumor. Shortly afterwards, however, inflammatory fibroid polyps also revealed PDGFRA mutations. Subsequently, gastrointestinal CD34+ 'fibrous tumors' of uncertain classification were described in a germline PDGFRA-mutant context. Our aim was to characterize the syndrome produced by germline PDGFRA mutations and establish diagnostic criteria and management strategies for this hitherto puzzling disease. We studied a kindred displaying multiple gastrointestinal mesenchymal tumors, comparing it with published families/individuals with possible analogous conditions. We identified a novel inherited PDGFRA mutation (P653L), constituting the third reported example of familial PDGFRA mutation. In adult mutants we detected inflammatory fibroid polyps, gastric GISTs and gastrointestinal fibrous tumors of uncertain nosology. We demonstrate that the syndrome formerly defined as INF/NF3b (exemplified by the family reported herein) is simplistically considered a form of familial GIST, because inflammatory fibroid polyps often prevail. Fibrous tumors appear variants of inflammatory fibroid polyps. 'INF/NF3b' and 'familial GIST' are misleading terms which we propose changing to 'PDGFRA-mutant syndrome'. In this condition, unlike KIT-dependent familial GIST syndromes, if present, GISTs are stomach-restricted and diffuse Cajal cell hyperplasia is not observed. This restriction of GISTs to the stomach in PDGFRA-mutant syndrome: (i) focuses oncological concern on gastric masses, as inflammatory fibroid polyps are benign; (ii) supports a selective role of gastric environment for PDGFRA mutations to elicit GISTs, justifying the known predilection for stomach of sporadic PDGFRA-mutant GISTs. An awareness that inflammatory fibroid polyps, relatively common among gastrointestinal mesenchymal tumors, may be the prevailing tumor in PDGFRA-mutant syndrome could eventually reveal an unsuspected prevalence of this condition.
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ricci
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Maurizio
authors.identifier: 0000000262606310
authors.initials: M
authors.lastname: Martini
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Tonia
authors.initials: T
authors.lastname: Cenci
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Carbone
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Lanza
authors.affiliation: Department of Surgery, Catholic University, Rome, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Biondi
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Rindi
authors.affiliation: Department of Oncology, Catholic University, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Cassano
authors.affiliation: Department of Digestive Endoscopy, Catholic University, Rome, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Larghi
authors.affiliation: Department of Surgery, Catholic University, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Persiani
authors.affiliation: Department of Pathology, Catholic University, Rome, Italy.
authors.forename: Luigi M
authors.initials: LM
authors.lastname: Larocca
mesh_terms: D000328:Adult; D000368:Aged; D003111:Colonic Polyps / Q000235:genetics* / Q000473:pathology; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000235:genetics* / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics*; D013577:Syndrome
chemical_list: D020796:Receptor, Platelet-Derived Growth Factor alpha