Ophthalmic Pathology

Our ophthalmic pathology service is run in collaboration with Singapore General Hospital (SGH) Department of Anatomical Pathology and Cytology. All types of ocular pathology specimens are processed at the SGH Histopathology and Cytology Sections, including whole globes, orbital exenteration, eyelid biopsies, conjunctival biopsies, corneal penetrating keratoplasties including deep lamellar keratoplasties and endothelial keratoplasties, phacoemulsification and vitrectomy specimens. The services available include:

1. Routine surgical biopsies

2. Frozen section service

3. Specialised biopsies:      
     - Ocular and orbital lymphoma diagnosis

4. Cytology

5. Immunofluorescence for Ocular cicatrial pemphigoid and other specific conditions

6. Immunohistochemistry

7. Electron microscopy

8. Polymerase chain reaction (PCR)     

These services are available through the Histopathology and Cytology Sections under the Department of Pathology at SGH. Please visit these highlighted links for further information.

Consultation services are also available. Please contact the laboratory at Tel: +65 6321 4008 for charges.  Slides and requests should be addressed to:

Dr Anita Chan Histopathology Pathology Department Singapore General Hospital 20 College Road Level 10, Diagnostics Tower, Academia Singapore 169856

Special instructions on Specimen Handling

1. Specimens for routine surgical biopsies should be sent in clean containers or bags with 10% buffered neutral formalin, unless otherwise stated.

2. Specimens for frozen sections should be sent without fixative and oriented if necessary.

3. Whenever possible, there should be one specimen per container. If multiple specimens  are placed in one container, they should be clearly identified by size or suture marking.  This information should be included in the Histopathology Request Form.

4. Multiple small specimens, such as conjunctival biopsies, should be mounted on a piece  of filter paper and properly labelled/oriented prior to immersing face downward in  formalin-filled containers.

5. Large specimens such as exenteration specimens and globes should be completely  immersed facing downward in formalin and containers tightly secured. Please note that  large exenteration specimens will require longer fixation duration and hence a longer  time for reporting.

6. Do not force a large specimen into a small container. Large specimens must be completely immersed in formalin for proper fixation.

7. For specimens where orientation is important, mark or tag the specimen. 

8. Do not crush specimens with forceps, haemostats or other instruments. Avoid using cautery.

9. Label each container with the patient’s name, identity card or admission number, the source of the specimen and nature of specimen. Use the printed sticky label.

10. Specimens for routine histopathology examination will be collected by porter services as specified under specimen collection services. Do not despatch specimen via the pneumatic system.

11. Urgent specimens should be marked prominently and despatched immediately by clinic/theatre staff.      

The Histopathology Request Form

All specimens should be accompanied by a Histopathology/Cytology Request Form. The request form must include:

1. Patient’s name, age, gender and identification number

2. The hospital and ward number, or name of clinic and telephone number, as this  facilitates despatch of reports

3. Summary of clinical history

4. Operative findings

5. Type of sample and anatomical site

6. Provisional diagnosis

7. Name of physician/surgeon in charge of case

8. Previous biopsy number or date of previous operation

Failure to provide all the above information will delay turnaround time for the histopathology report. 

When more than one specimen is sent from the same patient at the same operation, use only one form.

Specialised Investigations: Type of Examination and Their Submission Requirements

Cytology
Ophthalmic cytological specimens include aqueous and vitreous samples and require immediate fixation with Preservecyte© or liquid preservatives as used for cervical PAP examination such as Thinprep© because cells in these fluids will degenerate within one hour even with refrigeration.

Please contact the Cytology Lab at (65) 6321 4954 to obtain Preservecyte fixative© prior to procedure. All samples must be clearly labelled with the patient’s name and unique identification number. All tests requested (e.g. detection of TB, fungi, crystals, immunohistochemistry, cell block preparation) must be clearly indicated on the form.

Please contact the Cytology Lab at 6321 4954 for urgent specimens that require same-day reporting. Urgent cytology specimens should be indicated on the request form and delivered immediately by hand to the Cytology Lab.

Frozen Section for cicatrizing conjunctival disorders
Frozen section service is provided at the frozen section lab in the Operating Theatre Suite at SGH from Monday to Friday, 8.30 am to 5.00 pm. Please contact the section at (65) 6321 3530/3763. If frozen section is required outside these hours, please contact the laboratory at (65) 6321 4008 before 4.30 pm and contact the SGH OT for the technician/pathologist on call. 

Submit specimens in fresh state as soon as possible. Containers should not contain formalin.

When sending margins for frozen section assessment, please label each margin individually and do not send main specimen meant for paraffin processing.

Label containers with patient’s name, NRIC number and anatomic source of specimen.

Fill up only ONE Histopathological investigation request form for the frozen section assessment of margins and await the return (original/ faxed copy) of the HISTOPATHOLOGICAL FROZEN SECTION FORM (from SGH Main OT) for the addition and subsequent despatch of the remaining routine/ paraffin biopsy specimens.  Do not send the routine biopsy specimen in a separate routine histology form. Include telephone number and/or intercom contact number for verbal communication of results.

Immunohistochemistry
Contact pathologists directly if additional stains are requested or for further information, if necessary. Immunofluorescence

Contact the pathologist directly to arrange for processing.  Fresh tissue is required. Specimen is wrapped in aluminium foil, placed in a cryotube and delivered to the lab on ice.  Contact the laboratory at (65) 6321 4008 for further information, if necessary.

Electron Microscopy
Contact the pathologist directly to arrange for processing.  Specimen is placed in 2.5% glutaraldehyde in cacodylate buffer (the time for which the tissue is placed into fixative must be recorded).  Contact the laboratory (Tel: 6321 4008) for further information, if necessary.

Polymerase Chain Reaction (PCR)
Contact the pathologists directly to arrange for additional tests.  This is for assessment of IgH gene and T-cell receptor gamma gene rearrangements and evaluation of the clonality of B and T cell lymphoproliferative disorders which is performed in other subdivision of Pathology. Paraffin embedded or fresh/frozen tissue is required. Other tests available include TB PCR are also available.

Please contact the laboratory at (65) 6321 4008 for further information.