Professor Emeritus

William Halliday

Department of Laboratory Medicine & Pathobiology


Hospital for Sick Children (SickKids)
Paediatric Laboratory Medicine, 555 University Ave.. Rm 3205, Toronto, Ontario Canada M5G 1X8
Clinical Interests
Pathology: Neuropathology
Appointment Status

Research Synopsis

Dr. Halliday is a clinically oriented Neuropathologist with a longstanding interest in correlative studies, particularly clinical-pathological and radiological-pathological correlations. Expertise with morphological investigations is shared with collaborative research studies, especially in the area of oncology (retinoblastoma). Central nervous system traumatic injury, particularly as it relates to infants, is an ongoing interest.


Recent Publications


Dimaras H, Khetan V, Halliday W, Orlic M, Prigoda NL, Piovesan B, Marrano P, Corson TW, Eagle RC Jr, Squire JA, Gallie BL. Loss RB1 induces non-proliferative retinoma; increasing genomic instability correlates with progression to retinoblastoma. Hum Mol Genet 2008; 17(10): 1363-72.

Gessi M, Giangaspero F, Lauriola L, Gardiman M, Scheithauer BW, Halliday W, Hawkins C, Rosenblum MK, Burger PC, Eberhart CG. Embryonal tumors with abundant neuropil and true rosettes: a distinctive CNS primitive neuroectodermal tumor. Am J Surg Pathol. 2009 Feb;33(2):211-7.

Elbers J, Halliday W, Hawkins C, Hutchinson C, Benseler SM. Brain biopsy in children with primary small-vessel central nervous system vasculitis. Ann Neurol 2010 Nov; 68(5):602-10.

Ibrahim GM, Huang A, Halliday W, Dirks PB, Malkin D, Baskin B, Shago M, Hawkins C. Cribriform neuroepithelial tumour: novel clinicopathological, ultrastructural and cytogenetic findings.  Acta Neuropathol 2011 122:511-5

Soh SY, Dimaras H, Gupta A, Rushlow D, Swallow C, Crump M, Halliday W, Doyle JJ, Babyn P, Heon E, Gallie BL and Chan, HSL. Adult Ovarian Retinoblastoma Genomic Profile Distinct From Prior Childhood Eye Tumor. Arch Ophthalmol. 2011 Aug; 129(8):1101-1104.