Here is a selection of new images from our free, online textbook:

Lymphoma & related disorders > Prolymphocytic leukemia
Diffuse marrow involvement by medium to large sized cells with prominent nucleoli (200x, H&E).
Contributed by Richard K. Wood, M.D. and Dietrich Werner, M.D.

Ovary > Thecoma
Well circumscribed, firm, yellow-tan mass.
Contributed by Victoria Collins, M.D. and Tamara Kalir, M.D., Ph.D.

Prostate gland & seminal vesicles > Anatomy & histology
Here, the central zone cells are hyperplastic. Despite the cribriform structure, the bland nuclei rule out intraepithelial neoplasia or cribriform cancer. Also note the surrounding dense stroma of the central zone.
Contributed by Kenneth A. Iczkowski, M.D.

Prostate gland & seminal vesicles > Malakoplakia
Michaelis-Gutmann bodies highlighted by arrows.
Contributed by Theodorus van der Kwast, M.D., Ph.D.

Small intestine & ampulla > GIST
Small intestinal GIST with skeinoid fibers.
Contributed by Shefali Chopra, M.D.