title: Atypical Spitz Tumors: A Diagnostic Challenge.
abstract: Spitzoid melanocytic lesions encompass a spectrum from benign Spitz nevi to malignant spitzoid melanomas. Spitzoid melanocytic neoplasms have significant morphologic and molecular differences from conventional melanocytic lesions, and prediction of biologic behavior and metastatic risk may be difficult. Most challenging is the atypical Spitz tumor, a borderline spitzoid melanocytic lesion of uncertain malignant potential that has overlapping histologic features with conventional Spitz nevus and spitzoid melanoma. Atypical Spitz tumors involve the sentinel lymph nodes at a greater frequency than conventional melanoma and frequently harbor chromosomal copy number changes, yet most cases follow an indolent course. Herein we review the clinical, microscopic, and molecular features of atypical Spitz tumors, including recent molecular advances, including the potential prognostic significance of chromosomal abnormalities, such as homozygous CDKN2A loss.
authors.affiliation: From the Department of Dermatology (Drs K. L. Harms, Lowe, Fullen, and P. W. Harms), the Comprehensive Cancer Center (Dr K. L. Harms), and the Department of Dermatology and Pathology (Drs Lowe, Fullen, and P. W. Harms), University of Michigan Medical School, Ann Arbor.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Harms
authors.forename: Lori
authors.initials: L
authors.lastname: Lowe
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Fullen
authors.forename: Paul W
authors.initials: PW
authors.lastname: Harms
mesh_terms: D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics; D003937:Diagnosis, Differential; D017353:Gene Deletion; D006801:Humans; D008544:Melanocytes / Q000378:metabolism / Q000473:pathology*; D008545:Melanoma / Q000175:diagnosis* / Q000235:genetics / Q000628:therapy; D018332:Nevus, Epithelioid and Spindle Cell / Q000175:diagnosis* / Q000235:genetics / Q000628:therapy; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000628:therapy
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16