Pathology

Paediatric pathology is a distinct discipline that links the fundamental molecular and cellular abnormalities underlying disease processes in children to the clinical signs and symptoms of those diseases. Using techniques such as histology, cytology, morphometry, enzyme histochemistry, immunochemistry, in situ hybridization, electron microscopy and molecular biology, the pathologist pursues the diagnosis and pathogenesis of these important diseases in children. 

Labs & services

Autopsy Services

Our division performs hospital-consented autopsies, and provides a consultation service for the examination of post-mortem tissues including referred-in cases from the Coroner’s Office or outside hospitals, glass slides, organ blocks, or referral of fetuses or neonatal infants for a complete post-mortem examination. We provide an efficient and comprehensive consultation service to hospitals throughout Ontario, and will review selected cases from outside of this geographic area. Information about the procedure for handling specific cases is available. 

Electron Microscopy (EM) 

Our Electron Microscopy Facility has the capability to perform highly specialized testing and their applications to paediatric diseases, including examination of metabolic and storage diseases, examination of cilia, renal biopsy evaluation, muscle biopsy evaluation, scanning electron microscopy evaluation of hair specimens for variations caused by genetic abnormalities, evaluation of congenital enteropathies (e.g., microvillous inclusion disease), urinary stone analysis and specialized research techniques such as cryoimmobilization and immunogold labeling. 

Histology/Histochemistry 

We provide histology services which include consultations and histotechnology techniques on surgical, cytological, autopsy, veterinary and industrial research materials. This involves processing, embedding, microtomy and/or staining of paraffin-embedded and frozen tissues with a variety of specialized histochemical stains, many of which are specialized paediatric stains (e.g., acetylcholinesterase for the diagnosis of Hirschsprung disease). 

Immunopathology 

Immunohistochemistry and most recently in situ hybridization has contributed greatly to modern diagnostic pathology due to its specificity and sensitivity. For the last two decades, we have developed a comprehensive range of antibody markers and probes for immunohistochemical diagnostic service, many of which are paediatric-specific, and we develop new antibody tests regularly.  

Molecular Pathology 

The Molecular Pathology Laboratory is currently expanding its test menu and incorporating several new technologies to aid in the diagnosis, prognosis and therapeutic decision making in paediatric cancers. In addition to PCR and RTPCR-based assays we now offer SNP/microarray testing of tumour tissue for medulloblastoma, low-grade glioma and neuroblastoma, which allows for the detection of gene copy number changes and variants; NanoString® assays for medulloblastoma (subtyping into the four main molecular categories) and sarcoma (detection of diagnostically specific fusion transcripts). In collaboration with molecular hematopathology, we are using a NanoString® assay for the detection of specific fusion genes in paediatric leukemia.

Morphometry

We perform morphometric analysis on glass slides, photomicrographs (negatives or prints), transmission electron micrographs, and digitized images. This includes consultations, training and analysis on all types of materials, including surgical, autopsy and research specimens. This involves capturing images from raw materials, counting and measuring cells and tissue structures, plotting histograms and/or graphs, and providing final statistical analysis aided by our computerized systems.

Neuropathology

The Neuropathology Laboratory specializes in handling surgical, autopsy and research specimens for neurosurgery, neurology, ophthalmology, orthopaedics and plastic surgery. 

Our expertise includes the following procedures: muscle biopsies and muscle histograms, nerve biopsies, cryotomy/cryosections, Golgi silver preparation, enzyme histochemical staining techniques, as well as processing, embedding, microtomy and staining of paraffin embedded tissue and frozen tissue. We also provide consultation and hands-on-training for most techniques including immunohistochemistry.