Dermatopathology Laboratory at St Thomas' Hospital
Dermatopathology is a UKAS accredited medical laboratory (No.8126), accredited to ISO15189:2022 for the tests listed in the schedule of accreditation on the UKAS website (https://www.ukas.com/wp-content/uploads/schedule_uploads/00007/8126-Medi...).
The Dermatopathology laboratory is known as a centre of excellence for dermatological specimens. The laboratory service is a stand-alone service and independent of the main histopathology services. It is integral to the St John’s Institute of Dermatology which is a national tertiary referral centre, and as such staff are experienced in a wide range of histological based investigations with both formalin fixed and fresh tissue material.
The laboratory processes over 14000 cases per year in the main laboratory. It performs over 24 000 immunocytochemistry tests per annum. The laboratory also deals with 1000 cases of Mohs per year. All the staff are rotational within these various laboratory frameworks and play an important role in the patient management of skin cancers for the Trust and surrounding GP services. The staff are actively involved in teaching and demonstrating Mohs procedures to qualified biomedical scientists both within the working environment and also as guest lecturers at both national and international conferences.
The laboratory also patented a new histological product to improve the process of dealing with hard tissue samples and manufactured this through an external company for use in histopathology laboratories both nationally and internationally.
The Dermatopathology Consultant team consists of medical staff who regularly provide input at multiple disciplinary team meetings with clinicians and other medical professionals. They provide support and guidance on optimal tissue preparations and additional advanced tests. The deputy chief examiner for Cellular Pathology for the Institute of Biomedical Science is a member of the Dermatopathology laboratory staff as well as being a UKNEQAS Immunocytochemistry. The Consultants are fully qualified dermatopathologists of national and international standing and actively involved in academic dermatopathology.
The laboratory provides a routine histopathology service assessing skin biopsies from patients with suspected cancer and inflammatory diseases, including the specialised study of alopecia. The departments routine turn-around times for the issuing of results are within 2-5 working days for wet specimens received . The department is a national referral centre for skin pathology and deals with over two and half thousand referral cases from other histopathology laboratories both nationally and internationally. The routine turn-around time for these complex cases is 15 working days.
The laboratory offers an expanding immunocytochemistry service for the purpose of typing and the delination of various skin cancers.
The laboratory specialises in Mohs and slow Mohs micrographic surgery techniques for the removal of skin cancers. The work involves extensive section cutting of fresh frozen tissue in order to demonstrate more precise clearance of tumour margins. For specific tumour types and samples with a known risk of infection, the slow Mohs procedure is used which involves formalin fixation and paraffin processing of the tissue. See the attached User Guide for further information.
All services are provided from the Dermatopathology laboratory based at St Thomas's Hospital, with the exception of the Mohs service which is based at the Guy's Hospital Cancer Centre. Any specimens requiring the slow Mohs procedure are sent from the Cancer Centre to the St Thomas's laboratory for processing.
Samples may be sent from clinicians within the Trust's dermatology clinics and plastic surgery units, as well as local GPs. The department also provides processing of private patient samples from a multitude of dermatologists from all over the UK. Referral cases are received from numerous national hospitals and also from a smaller number of international centres.
More information on GSTT website
