title: Arachnoid cyst: a further anomaly associated with Kallmann syndrome?
abstract: BACKGROUND
  Kallmann syndrome (KS) is defined by the association of hypogonadotropic hypogonadism and anosmia. It is characterized by a significant clinical and genetic heterogeneity; actually, it may present several non-reproductive non-olfactory anomalies, and all the ways of genetic transmission can be involved in the inheritance of the disease. Although six pathogenesis-related genes have been identified so far, KS remains sporadic in 70 % of the cases, and the genetic diagnosis is not available for all of them. The purpose of this paper is to present a further disease that can enrich the wide spectrum of KS variability, that is cerebral arachnoid cyst.
  
  
  METHODS
  This 11-year-old boy presented with the typical characteristics of KS together with those related to a sylvian arachnoid cyst. He was admitted because of worsening headache. At the admission, the physical examination revealed eunuchoid aspect, micropenis, previous cryptorchidism, and anosmia. MRI pointed out a large, left sylvian arachnoid cyst, agenesia of the olfactory bulbs/tracts complex, and hypoplasia of the left olfactory sulcus. The child was operated on by endoscopic fenestration of the cyst, followed by transient external drainage for subdural hygroma and microscopic fenestration for recurrence of the cyst. His statural growth is normal but the sexual development still delayed in spite of hormone replacement therapy.
  
  
  CONCLUSIONS
  According to the present and the other four cases in the literature, arachnoid cyst should be included among the anomalies possibly accompanying KS date although this association seems to be occasional as far as embryogenesis and physiopathology are concerned.
authors.affiliation: Pediatric Neurosurgery, A. Gemelli Hospital, Largo A. Gemelli, 8, 00168, Rome, Italy. lmassimi@email.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Massimi
authors.affiliation: Pediatric Neurosurgery, A. Gemelli Hospital, Largo A. Gemelli, 8, 00168, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Izzo
authors.affiliation: Necker Hospital, Paris, France.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Paternoster
authors.affiliation: Pediatric Neurosurgery, A. Gemelli Hospital, Largo A. Gemelli, 8, 00168, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Frassanito
authors.affiliation: International Neuroscience Institute, Hannover, Germany.
authors.forename: Concezio
authors.initials: C
authors.lastname: Di Rocco
mesh_terms: D016080:Arachnoid Cysts / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000601:surgery*; D002648:Child; D020249:Hormone Replacement Therapy / Q000379:methods; D006801:Humans; D017436:Kallmann Syndrome / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male
keywords: Anosmia; Hypogonadotropic hypogonadism; Olfactory bulbs; Sylvian fissure