18F-FDG PET/CT Findings of MALT Lymphoma of Ureter

Abstract

Mucosa-associated lymphoid tissue (MALT) lymphoma origin from the ureter is exceedingly rare. We report FDG PET/CT findings of MALT lymphoma in the distal right ureter in a 55-year-old woman who presented right abdominal pain for 10 days. Ultrasound revealed a hypoechoic mass in the right pelvis, which was surrounding the distal right ureter. 18F-FDG PET/CT demonstrated a high FDG uptake by the mass along with several FDG-avid enlarged lymph nodes in the abdominal cavity. Postoperative pathology demonstrated the ureteral mass as a MALT lymphoma.

Urinary Endometriosis Misdiagnosed as Ureteral Malignant Tumor by PET/CT

“…However, it is rare in the ureter, 6 and even rare with increased FDG uptake 5,7 . The PET/CT findings in the presented case resemble malignant ureteral tumors such as urothelial carcinoma of the ureter 8 and ureteral mucosal-related lymphoma 9 . As a result, it may be difficult to distinguish between endometriosis and malignant ureteral tumors.…”

“…5,7 The PET/CT findings in the presented case resemble malignant ureteral tumors such as urothelial carcinoma of the ureter 8 and ureteral mucosal-related lymphoma. 9 As a result, it may be difficult to distinguish between endometriosis and malignant ureteral tumors. Endometriosis should be considered as one of the possibilities when similar FDG PET/CT findings are observed.…”

FDG PET/CT in a Case of Primary Lymphoma of the Ureter

“…[5][6][7][8] On FDG PET/CT, ureteral lymphoma lesions may show focal or segmental FDG uptake. [9][10][11][12][13][14][15][16] This case indicates that, although rare, primary lymphoma of the ureter should be included in the differential diagnosis of hypermetabolic ureteral lesions including urothelial carcinoma, 17 metastasis, 18 inflammatory hyperplasia, 19 and malakoplakia. 20,21…”

“…On CT or MRI, primary lymphoma of the ureter can appear as a solid mass or segmental circumferential wall thickening with enhancement 5–8 . On FDG PET/CT, ureteral lymphoma lesions may show focal or segmental FDG uptake 9–16 . This case indicates that, although rare, primary lymphoma of the ureter should be included in the differential diagnosis of hypermetabolic ureteral lesions including urothelial carcinoma, 17 metastasis, 18 inflammatory hyperplasia, 19 and malakoplakia 20,21 …”