Intraosseous lipomas originating from simple bone cysts

Tins, Bernhard J.; Berkowitz, Yaron J.; Konala, Praveen; Davies, Mark; Cassar-Pullicino, Victor N.; Lalam, Radhesh; Cool, Paul

Abstract

Purpose
Fatty or part-fatty intraosseous lesions are occasionally encountered while imaging the skeletal system. A number of case reports have proposed involution of calcaneal bone cysts to intraosseous lipomas, but this has never been proven. This paper sets out to prove that simple bone cysts (SBCs) can involute to fatty lesions indistinguishable from intraosseous lipomas.

Materials and methods
The pathology and PACS databases at 2 specialist orthopedic hospitals were retrospectively interrogated for all cases of intraosseous lipomas or SBCs with cross-sectional imaging follow-up for SBCs and precursor or follow-up imaging for intraosseous lipomas, in the time period from August 2007 to December 2016. For intraosseous lipoma cases, these were only included if change in imaging appearances was observed.

Results
There was no case of change in the appearance in intraosseous lipomas. Six cases of SBC with cross-sectional imaging follow-up were identified in one participating hospital and none in the other. The 6 cases were comprised of 4 male and 2 female patients. Two were located in the proximal humerus, one in the proximal tibia, and 3 in the os calcis. All cases demonstrated filling in of the cystic lesion with fat from the periphery, in 2 cases complete filling in, and in 4 cases partial fatty conversion.

Conclusion
SBCs can heal with fatty conversion of the cystic cavity, with partly cystic remnants. It is proposed that at least part of the so-called intraosseous lipomas are healed simple bone cysts.

Citation

Tins, B. J., Berkowitz, Y. J., Konala, P., Davies, M., Cassar-Pullicino, V. N., Lalam, R., & Cool, P. (2021). Intraosseous lipomas originating from simple bone cysts. Skeletal Radiology, 50(4), 801-806. https://doi.org/10.1007/s00256-020-03628-0

• Journal Article Type: Article
• Acceptance Date: Sep 23, 2020
• Online Publication Date: Oct 1, 2020
• Publication Date: 2021-04
• Deposit Date: Jun 23, 2023
• Journal: Skeletal Radiology
• Print ISSN: 0364-2348
• Electronic ISSN: 1432-2161
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 50
• Issue: 4
• Pages: 801-806
• DOI: https://doi.org/10.1007/s00256-020-03628-0
• Keywords: Radiology, Nuclear Medicine and imaging
• Additional Information: Received: 27 February 2020; Revised: 22 September 2020; Accepted: 23 September 2020; First Online: 1 October 2020; : The institutional review boards at these institutions approved the retrospective study and waived the need for informed patient consent.; : The authors declare that they have no conflict of interest.