Retroperitoneal Extraskeletal Osteosarcoma without Calcification Mimicking Pancreas Tumor: CT Imaging of a Case Report

• Main Authors: Jung Won Kim, Kyung Eun Bae, Kyeong Mee Park, Jae Hyung Kim, Myeong Ja Jeong, Soung Hee Kim, Ji Young Kim, Soo Hyun Kim, Mi Jin Kang, Ji Hae Lee, Tae Gyu Kim
• Format: Article
• Language: English
• Published: The Korean Society of Radiology 2018-05-01
• Series: 대한영상의학회지
• Subjects: retroperitoneal space; osteosarcoma; ossification; tomography; x-ray computed
• Online Access: https://doi.org/10.3348/jksr.2018.78.5.340
• ISSN: 1738-2637; 2288-2928

Retroperitoneal extraskeletal osteosarcoma is a rare tumor. Typical imaging findings include a soft tissue mass accompanied with internal calcifications. The authors encountered a case involving a 44-year-old woman with a large retroperitoneal extraskeletal osteosarcoma, without calcification, that mimicked a pancreatic tumor. The present report highlights computed tomography features of retroperitoneal extraskeletal osteosarcoma, followed by a brief literature review. It is challenging for radiologists to diagnose retroperitoneal masses. However, in patients who present with large retroperitoneal masses, combined with clinical information including the elevation of serum alkaline phosphatase levels, retroperitoneal extraskeletal osteosarcoma should be considered in the differential diagnosis, even if the mass does not exhibit a gross calcification on the imaging.