Principles of Manual Tissue Processing in an Oral and Maxillofacial Pathology Laboratory in Lagos, Nigeria.

INTRODUCTION

Tissue processing describes the steps involved in infiltrating a well fixed tissue with wax for section cutting on a microtome. Paraffin tissue processing can be performed either manually or by using an automated tissue processor and errors in any of the steps involved would significantly affect histopathology. The aim of this article was to describe to principles of manual tissue processing as performed in the Oral and Maxillofacial Pathology Laboratory of the College of Medicine, University of Lagos, Nigeria (OMFP-CMUL Lab).

METHODS

We report the principles of manual tissue processing as performed in the OMFP-CMUL lab using the index case of an 11-year-old girl with a histopathologic diagnosis of unicystic ameloblastoma.

RESULTS

Steps of tissue processing included fixation, specimen accessioning, gross examination, decalcification (for tissue specimens containing calcium deposits), dehydration, clearing, infiltration, embedding, sectioning, labeling of tissue blocks, tissue floatation bathing, making the slide and numbering, staining, drying, cover-slipping, and microscopic examination.

DISCUSSION

Common errors seen in histopathology laboratories were avoided by the quality control practices of the residents, consultants, laboratory scientists and technicians within the department.