title: Mucocutaneous neuromas: an underrecognized manifestation of PTEN hamartoma-tumor syndrome.
abstract: BACKGROUND
  The spectrum of clinical findings associated with PTEN tumor suppressor gene germline mutations, referred to as PTEN hamartoma-tumor syndrome (PHTS), includes Cowden and Bannayan-Riley-Ruvalcaba syndromes. Although the skin is the ectodermal structure most often affected by these autosomal dominant genodermatoses, abnormalities of neural tissues are frequently observed.
  
  
  METHODS
  We describe a 5-year-old boy with macrocephaly, prominent corneal nerves, and progressive development of multiple painful, dome-shaped, translucent pink to skin-colored papules on the vermilion portion of the upper lip, fingers, palms, and shins. Histologic evaluation demonstrated dermal proliferation of well-demarcated nerve bundles associated with abundant mucin and surrounded by a distinct perineural sheath, findings diagnostic of a nonencapsulated neuroma. Genetic analysis revealed a novel heterozygous germline nonsense mutation in PTEN, predicted to result in a truncated PTEN protein. To our knowledge, this represents the first report of multiple neuromas as the sole mucocutaneous manifestation of PHTS.
  
  
  CONCLUSIONS
  This article highlights neuromas as a cutaneous sign of PHTS, drawing attention to manifestations of PHTS in neural tissues of the skin, eye, gastrointestinal tract, and brain. Along with multiple endocrine neoplasia type 2B, PHTS should be considered in the differential diagnosis of multiple mucocutaneous neuromas, particularly those involving extrafacial sites.
authors.affiliation: Ronald O. Perelman Department of Dermatology and Departments of Pathology and Pediatrics, New York University School of Medicine, New York, USA. schafj04@med.nyu.edu
authors.forename: Julie V
authors.initials: JV
authors.lastname: Schaffer
authors.forename: Hideko
authors.initials: H
authors.lastname: Kamino
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Witkiewicz
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: McNiff
authors.forename: Seth J
authors.initials: SJ
authors.lastname: Orlow
mesh_terms: D002675:Child, Preschool; D003937:Diagnosis, Differential; D006223:Hamartoma Syndrome, Multiple / Q000175:diagnosis* / Q000473:pathology; D006225:Hand; D006801:Humans; D007866:Leg; D008046:Lip; D008297:Male; D009154:Mutation; D009463:Neuroma / Q000175:diagnosis* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000235:genetics; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology
chemical_list: D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human