Imaging and Clinical Findings of Primary Malignant Fibrous Histiocytoma of the Urinary Bladder: A Case Report

• Published in: Journal of the Korean Society of Radiology Vol. 85; no. 3; pp. 654 - 660
• Main Authors: Lee, Yoon Jung, Lee, Eun Ji, Kim, Jae Heon, Jin, So Young, Hong, Seong Sook, Hwang, Jiyoung, Chang, Yun-Woo
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Radiology 01.05.2024; 대한영상의학회
• Subjects: Genitourinary Imaging; magnetic resonance imaging; malignant fibrous histiocytoma; urinary bladder; 방사선과학; Magnetic Resonance Imaging; Urinary Bladder; Malignant Fibrous Histiocytoma
• ISSN: 2951-0805; 2951-0805
• DOI: 10.3348/jksr.2023.0083

Primary malignant fibrous histiocytoma (MFH) is a malignant tumor of mesenchymal origin that rarely occurs in the urinary tract, particularly in the urinary bladder. Unlike urothelial carcinoma, which accounts for most bladder cancers, it occurs in the submucosal portion of the bladder wall and consists of the lamina propria, muscularis propria, and adventitia. It is presumed to originate from poorly differentiated pluripotent mesenchymal cells in which fibroblasts and histiocytes are partially differentiated. Radiologically, it is known as the "non-papillary tumor" and is commonly diagnosed as a large mass without necrosis, which shows invasion beyond the muscularis propia. Although the prognosis of this rare malignancy depends on pathological parameters, it generally has a poor prognosis with high local tumor recurrence. Here, we present a case of primary MFH in the urinary bladder with clinical symptoms of lower abdominal pain without gross hematuria that recurred rapidly and showed an aggressive disease course.