Myxoma of the renal pelvis masquerading pelviureteric stenosis: conservative limited resection with renal preservation: case presentation and literature review

Myxoid Pseudotumor Involving the Renal Sinus: Clinicopathologic Study of 33 Cases Supporting a Distinct Benign Non-neoplastic Lesion

We describe 33 cases of myxoid pseudotumor involving the renal sinus from 31 patients. Patients included 21 men and 10 women, ages 30 to 95 years. Twenty-seven cases (82%) had an associated malignancy, including urothelial carcinoma of the renal pelvis (22 cases), clear cell renal cell carcinoma (3 cases), urothelial carcinoma of the bladder (1 case), and poorly differentiated carcinoma of uncertain lineage (1 case). The remaining 6 (18%) had no associated malignancy and included 3 nephrectomies for ureteral stricture, 2 ureteropelvic junction repairs, and 1 resection of a "periureteral mass" (subsequently shown to be myxoid pseudotumor). Myxoid pseudotumor was identified by preoperative computed tomography imaging in 2 patients (6%) and identified by the gross dissector in 9 cases (27%). The mean size was 14 mm (range: 5 to 38 mm). All cases had an admixture of adipocytes, myxoid stromal matrix, variable collagenization, and a hypocellular population of bland spindled and stellate stromal cells. No multilobated atypical stromal cells were present. Clinical follow-up was available for 28 patients (90%), ranging from 1 to 132 months (mean: 24.6 mo). No patients had adverse events related to the myxoid pseudotumor. Myxoid pseudotumor of the renal sinus is often associated with a variety of adjacent neoplastic and non-neoplastic conditions and may present as a mass lesion detectable by imaging and/or gross inspection. Awareness of this benign process is important to avoid confusion with a neoplasm, especially liposarcoma.

Myxoma of urinary bladder (case report)

Bladder myxoma is a very rare tumor that happens in a benign manner. The mesenchymal origin is typically the supply of these tumors. This tumor is usually diagnosed by the excisional biopsy due to the difficulty of diagnosis preoperatively as different bladder tumors' types. During this paper, we tend to represent a case report of this terribly rare mesenchymal growth within the urinary bladder which is an unusual location for myxoma tumors to occur. A 48-year-old feminine was hospitalized because of obscure abdominal pain. The patient underwent partial cystectomy, and the histopathology reported the presence of myxoma of urinary bladder.