title: Non-exophytic Lambl excrescences of aortic valves: a morphological study.
abstract: OBJECTIVE
  To elucidate the histopathological findings of classical Lambl excrescences (LEs) and non-exophytic LEs (non-ex LEs) without excrescent papillary features.
  
  
  RESULTS
  We examined 126 aortic valves (AVs) and revealed LEs (non-ex and/or classical), non-ex LEs and classical LEs in 106, 78 and 88 AVs, respectively. The detection of non-ex LEs was challenging, but elastica van Gieson stain highlighted their presence. Non-ex and classical LEs chiefly involved the ventricular regions, favoured posterior cusps and coexisted in the same areas of 31 AVs. A possible transformation of classical LEs into non-ex LEs was suggested histologically in 39 AVs. Non-ex LEs were associated with age of >70 years (P < 0.001) and marked deformity (P = 0.007). Classical LEs were associated inversely with marked deformity (P < 0.001), but not with age of >70 years. Compared with age- and sex-matched control AVs, non-ex LEs and marked deformity in dysfunctional AVs were more common (P = 0.037 and P < 0.001, respectively), but classical LEs were less common (P = 0.021).
  
  
  CONCLUSIONS
  Non-ex LEs have subtle features but are a common form of LEs, and seem to develop from classical LEs. AV dysfunction-related marked deformity can promote non-ex LEs.
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.|Health Care Center, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Matsukuma
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Koga
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeo
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.
authors.forename: Kimi
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.
authors.forename: Kazuma
authors.initials: K
authors.lastname: Mori
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, Tokyo, Japan.
authors.forename: Kimiya
authors.initials: K
authors.lastname: Sato
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000473:pathology*; D005260:Female; D006349:Heart Valve Diseases / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: Lambl excrescence; aortic valve; papillary fibroelastoma