Fig. 2
From: Chondroblastoma of the patella with pathological fracture in an adolescent: a case report
Histological appearance of the tumor (b, c, d H&E). a The gross appearance of the tissue specimen showed it contained a mixture of soft, friable, yellow-white material and hemorrhage. b High-power photomicrograph showing round or polyhedral cells with oval nuclei in the areas of proliferation embedded in a chondroid matrix (× 100). c Focally, a clear cell change (black arrow) could be seen (× 200). d The nucleus was centrally placed, and a central, longitudinal nuclear groove (“coffee bean” nucleus) (white arrow) can be seen (× 400)