title: Nasal Chondromesenchymal Hamartoma (NCMH): a systematic review of the literature with a new case report.
abstract: BACKGROUND
  Nasal chondromesenchymal hamartoma (NCMH) is a very rare, benign tumour of the sinonasal tract usually presenting in infants. We present a systematic review of NCMH cases alongside a case report of an adult with asymptomatic NCMH.
  
  
  METHODS
  A systematic review was conducted in accordance with PRISMA guidelines. A PubMed, EMBASE and manual search through references of relevant publications was used to identify all published case-reports of NCMH. Data was collected from each case-report on: patient demographics, laterality, size and location of NCMH, presentation, co-morbidities, investigations, treatment and follow-up.
  
  
  RESULTS
  The systematic review identified 48 patients (including ours): 33 male, 15 female. Mean age was 9.6 years (range: 1 day-69 years) with the majority aged 1 year or younger at presentation (n = 18). Presentations included: nasal congestion (n = 17), nasal mass (n = 15) and eye signs (n = 12). NCMH also involved the paranasal sinuses (n = 26), orbit (n = 16) and skull-base (n = 14). All patients underwent operative resection of NCMH. A small 2014 case-series found DICER1 mutations in 6 NCMH patients, establishing a link to the DICER1 tumour spectrum.
  
  
  CONCLUSIONS
  NCMH is a rare cause of nasal masses in young children and adults. In light of the newly established link between NCMH and DICER1 mutations surgeons should be vigilant for associated DICER1 tumours, as NCMH may be the 'herald tumour' of this disease spectrum.
authors.affiliation: Barts and The London School of Medicine and Dentistry, The Blizard Institute of Cell and Molecular Science, 4 Newark Street, Whitechapel, E1 2AT, London, UK. katrina.a.mason@gmail.com.
authors.forename: Katrina Anna
authors.initials: KA
authors.lastname: Mason
authors.affiliation: Colchester Hospital University NHS Foundation Trust, Colchester, UK. annakan.navaratnam@nhs.net.
authors.forename: Annakan
authors.initials: A
authors.lastname: Navaratnam
authors.affiliation: Barts and The London School of Medicine and Dentistry, The Blizard Institute of Cell and Molecular Science, 4 Newark Street, Whitechapel, E1 2AT, London, UK. e.theodorakopoulou@nhs.net.
authors.forename: Evgenia
authors.initials: E
authors.lastname: Theodorakopoulou
authors.affiliation: Colchester Hospital University NHS Foundation Trust, Colchester, UK. chokks@btopenworld.com.
authors.forename: Perumal Gounder
authors.initials: PG
authors.lastname: Chokkalingam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D053487:DEAD-box RNA Helicases / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D006222:Hamartoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009668:Nose Diseases / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000601:surgery; D010254:Paranasal Sinus Diseases / Q000175:diagnosis / Q000235:genetics / Q000473:pathology / Q000601:surgery; D043244:Ribonuclease III / Q000235:genetics; D055815:Young Adult
chemical_list: C408087:DICER1 protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases