Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies

Abstract

Peripelvic and periureteric areas are frequently overlooked in the imaging evaluations of the urinary system on computed tomography and magnetic resonance imaging. Several neoplastic and non-neoplastic disorders and diseases including lipomatosis, angiomyolipoma and angiolipomatous proliferation, vascular lesions, lymphangiomatosis, Rosai-Dorfman disease, Erdheim-Chester disease, extramedullary hematopoiesis, IgG4-related disease, lymphoma, mesenchymal tumors, trauma, and Antopol-Goldman lesion may involve these areas. Differentiation of these benign or malignant pathologies among themselves and from primary renal pathologies is of utmost importance to expedite the triage of patients for correct treatment approach. In this article, we aim to increase the awareness of the imaging specialists to the typical and atypical imaging features of the entities affecting these areas.

Rosai-Dorfman Disease: A Case Report of Asymptomatic Isolated Renal Involvement

“…Gumeler and colleagues reported infiltrative renal hilar mass with ill-defined borders as a characteristic feature of renal RDD and suggested hypo-attenuated renal cortical nodules and subcapsular infiltration as other important imaging findings on CT. In the case described in their study, T1W and T2W imaging showed low signal intensity with mild enhancement on post-contrast images 14 . In 2019, Kmetz et al reported the most recent case of bilateral renal RDD in a 60-year-old Caucasian man with a history of anemia and thrombocytopenia of unknown etiology.…”

“…Although imaging studies are also not highly discriminative, they will help narrow the diagnosis. Modalities such as renal ultrasound, abdominopelvic CT, and MRI, along with FDG PET/CT scan could be considered as beneficial tools for identification of the lesion, evaluation of the extent of disease, image-guided biopsy, and even monitoring disease activity and response to therapy 14,15 . Due to the rarity of RDD, it is less likely for the urologist or radiologist to consider this diagnosis when observing an abnormal renal lesion on imaging; however, having a suspicion in mind might favorably change patient management and help prevent unnecessary nephrectomy.…”

A rare presentation of unilateral periureteral renal lymphangiomatosis

“…Parapelvic areas and the renal sinus are the commonly affected anatomical areas. [ 5 ] In cases when they are located within the renal parenchyma, they can mimic multilocular cystic disease of the kidney. [ 5 ] Lymphangiomatosis may sometimes extend from the peripelvic area into the periureteric area.…”

“…[ 5 ] In cases when they are located within the renal parenchyma, they can mimic multilocular cystic disease of the kidney. [ 5 ] Lymphangiomatosis may sometimes extend from the peripelvic area into the periureteric area. Renal lymphangiomatosis is usually bilateral with only few reported cases being unilateral.…”

Rosai‐Dorfman disease: A case report of asymptomatic isolated renal involvement

“…In the case described in their study, T1W and T2W imaging showed low signal intensity with mild enhancement on postcontrast images. 14 In 2019, Kmetz et al reported the most recent case of bilateral renal RDD in a 60‐year‐old Caucasian man with a history of anemia and thrombocytopenia of unknown etiology. Subsequent to identifying a left upper quadrant mass on palpation, CT scan was performed for the patient, revealing bilateral soft tissue masses in the perinephric space, measuring up to 22 cm on the left side.…”