Osteoclastic giant cell tumor of the pancreas: A distinct clinical and pathologic entity.

e14648 Background: Osteoclastic giant cell tumor of the pancreas (OGCTP) is a rare subtype of pancreatic cancer. It has been variably described in case reports as pancreatic cancer with pleomorphic, anaplastic, spindle cell, undifferentiated or mixed histology. Clinical and pathologic data regarding this tumor are very limited. Methods: We conducted a retrospective review of patient records with the above histologies at a single institution from 1994 to 2008. Archival pathology specimens were independently reviewed by two surgical pathologists (WP, DT). Results: Eleven patients with OGCTP were identified. Demographics: 9 males, median age = 66 (range 49-78), 10 Caucasian, 6 smokers. Median CA 19-9 was 70 IU/mL (range = 1.0-28,373). Site: 6 located in the body or tail, 5 locally advanced, 6 metastatic. A large, locally infiltrative mass was frequently seen on imaging studies. Pathologic examination revealed a histologically distinct entity consisting of a heterogeneous but characteristic mixture of bland o...