Pathology

noun

1. The branch of medicine concerned with the study of the nature of disease and its causes, processes, development, and consequences.
2. The medical specialty that provides microscopy and other laboratory services (e.g., cytology, histology) to clinicians.

   "The surgeon sent a specimen of the cyst to the pathology department for staining and analysis to determine its histologic subtype."

3. Pathosis: any deviation from a healthy or normal structure or function; abnormality; illness or malformation.