title: Clinical and histopathological characterization of cutaneous melanomas in the melanoblastoma-bearing Libechov minipig model.
abstract: Spontaneous animal tumors appear to be highly suitable models to study human oncology and cancer therapy. The aim of this study was to characterize the clinical and histological features of hereditary melanocytic lesions found in the French herd of melanoblastoma-bearing Libechov minipigs (MeLiM) and their Duroc crossbreeds. Clinically, we discriminated between three types of melanocytic skin lesions, which offer a lesion continuum from lentigo to metastatic melanomas. More than 70% of these lesions appear on piglets before they are 3 months old and preferentially on homogeneous black coat piglets. The incidence of melanoma reaches 50% in MeLiM. Most of the highly invasive melanomas regressed spontaneously in the first year of the piglet's life and the regression was followed by hair, skin and iris depigmentation. A histopathological study was conducted according to the human melanoma classification. Except for lentigo maligna, we observed the three main types of human melanoma in swine [superficial spreading melanoma (SSM), nodular or unclassified melanoma] with an excess of SSM (59-67%). The histological events leading to total spontaneous regression are chronologically described. The genetic predisposition, the high incidence of melanoma, the clinical and histopathological features similar to the human disease and the high rate of spontaneous regression offer an opportunity to use this model for studying genetic events controlling melanoma development and regression and the biological mechanisms involved in oncogenesis and anti-cancerous self-defense.
authors.affiliation: Laboratoire de Radiobiologie et Etude du Génome, CEA INRA, Jouy-en-Josas Cedex, France. vincentn@dsvidf.cea.fr
authors.forename: Silvia
authors.initials: S
authors.lastname: Vincent-Naulleau
authors.forename: Catherine
authors.initials: C
authors.lastname: Le Chalony
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Leplat
authors.forename: Stéphan
authors.initials: S
authors.lastname: Bouet
authors.forename: Christiane
authors.initials: C
authors.lastname: Bailly
authors.forename: Alain
authors.initials: A
authors.lastname: Spatz
authors.forename: Philippe
authors.initials: P
authors.lastname: Vielh
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Avril
authors.forename: Yves
authors.initials: Y
authors.lastname: Tricaud
authors.forename: Joseph
authors.initials: J
authors.lastname: Gruand
authors.forename: Vratislav
authors.initials: V
authors.lastname: Horak
authors.forename: Gérard
authors.initials: G
authors.lastname: Frelat
authors.forename: Claudine
authors.initials: C
authors.lastname: Geffrotin
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D018327:Hutchinson's Melanotic Freckle / Q000235:genetics / Q000473:pathology*; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000473:pathology*; D009365:Neoplasm Regression, Spontaneous / Q000473:pathology; D012878:Skin Neoplasms / Q000235:genetics / Q000473:pathology*; D013552:Swine; D013556:Swine, Miniature