title: Diplopia as presenting sign of Turcot syndrome.
abstract: OBJECTIVE
  To describe a patient with diplopia who was diagnosed with Turcot syndrome.
  
  
  METHODS
  A 10-year-old boy presented with a history of left-sided sixth and seventh nerve palsy. He underwent imaging of the brain and colon, a full ophthalmological and genetic work-up.
  
  
  RESULTS
  A 10-year-old boy was referred with combined left-sided sixth and seventh nerve palsy since 1 month without symptoms of raised intracranial pressure. BCVA was 6/6 in both eyes. Fundoscopy revealed bilateral, multiple, oval pigmented ocular fundus lesions (POFLs) in the 4 quadrants. These POFLs, together with the cranial nerve palsies raised the suspicion of Turcot syndrome, a familial neoplasia syndrome characterized by familial colorectal cancer and tumours of the central nervous system. Urgent MRI scan of the brain and stereotactic biopsy showed a primitive neuroectodermal tumour (PNET) at the pons. Coloscopy revealed multiple polyps. DNA analysis of the APC gene confirmed the clinical diagnosis of Turcot syndrome. The PNET was treated with combined radio- and chemotherapy. The patient underwent a prophylactic total colectomy as virtually all patients develop a carcinoma of the colorectal region if left untreated.
  
  
  CONCLUSIONS
  Although strabismus is not, diplopia in childhood is rare and seldom innocuous. It requires a prompt and thorough diagnostic evaluation, including thorough, dilated fundoscopy. The presence of POFLs combined with neurological symptoms suggestive of a brain tumour should alert the clinician of the possibility of Turcot syndrome. Recognition of this rare syndrome can lead to earlier diagnosis, which is vital for appropriate surveillance and early surgical intervention of the highly frequent neoplasias in Turcot Syndrome.
authors.affiliation: Department of Ophthalmology, Ghent University Hospital & Ghent University, De Pintelaan 185, 9000, Ghent, Belgium. Virginie.ninclaus@uzgent.be.
authors.forename: Virginie G S
authors.initials: VG
authors.lastname: Ninclaus
authors.affiliation: Department of Ophthalmology, Ghent University Hospital & Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Walraedt
authors.affiliation: Department of Neurosurgery, Ghent University Hospital & Ghent University, Ghent, Belgium.
authors.forename: Edward
authors.initials: E
authors.lastname: Baert
authors.affiliation: Department of Pediatric Hematology and Oncology, Ghent University Hospital & Ghent University, Ghent, Belgium.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Laureys
authors.affiliation: Department of Ophthalmology, Ghent University Hospital & Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.|Center for Medical Genetics, Ghent University Hospital & Ghent University, Ghent, Belgium.|Division of Ophthalmology & Center for Cellular & Molecular Therapeutics, The Childrens' Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Bart P
authors.initials: BP
authors.lastname: Leroy
authors.affiliation: Department of Ophthalmology, Ghent University Hospital & Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: De Zaeytijd
mesh_terms: D001932:Brain Neoplasms / Q000150:complications*; D002648:Child; D015179:Colorectal Neoplasms / Q000150:complications*; D004172:Diplopia / Q000209:etiology*; D006801:Humans; D008297:Male; D009386:Neoplastic Syndromes, Hereditary / Q000150:complications*
keywords: APC gene; Brain tumour; Diplopia in childhood; Familial neoplasia syndrome; Pigmented ocular fundus lesions; Turcot syndrome