We present a content-based image retrieval system that supports decision ma
king in clinical pathology. The image-guided decision support system locate
s, retrieves, and displays cases which exhibit morphological profiles consi
stent to the case in question. It uses an image database containing 261 dig
itized specimens which belong to three classes of lymphoproliferative disor
ders and a class of healthy leukocytes. The reliability of the central modu
le, the fast color segmenter, makes possible unsupervised on-line analysis
of the query image and extraction of the features of interest: shape, area,
and texture of the nucleus. The nuclear shape is characterized through sim
ilarity invariant Fourier descriptors, while the texture analysis is based
on a multiresolution simultaneous autoregressive model. The system performa
nce was assessed through ten-fold cross-validated classification and compar
ed with that of a human expert. To facilitate a natural man-machine interfa
ce, speech recognition and voice feedback are integrated. Client-server com
munication is multithreaded, Internet-based, and provides access to support
ing clinical records and video databases.