[PRIMARY MALIGNANT LYMPHOMA OF THE RENAL PELVIS : A CASE REPORT]

Area of Science:

• Oncology
• Urology
• Pathology

Background:

• Primary malignant lymphoma of the renal pelvis is exceptionally rare, with only 13 reported cases.
• Distinguishing renal pelvic lymphoma from urothelial carcinoma is often difficult due to nonspecific clinical and imaging findings.

Purpose of the Study:

• To report a case of primary renal pelvic diffuse large B-cell lymphoma (DLBCL).
• To emphasize the diagnostic challenges and the role of nephroureterectomy in managing renal pelvic masses.

Main Methods:

• A 63-year-old woman with symptoms of fever and flank pain underwent computed tomography (CT) and ureteroscopy.
• Retroperitoneal laparoscopic nephroureterectomy was performed due to recurrent urinary tract infections.
• Histopathological examination of the resected specimen confirmed DLBCL.

Main Results:

• CT revealed hydronephrosis, a renal pelvic mass, and para-aortic lymphadenopathy; cytology and ureteroscopy were inconclusive.
• Histopathology confirmed diffuse large B-cell lymphoma (DLBCL) with CD20 and CD79a positivity.
• The patient achieved complete remission 60 months post-chemotherapy (R-THP-COP) with regression of lymphadenopathy.

Conclusions:

• Preoperative diagnosis of renal pelvic lymphoma is challenging due to nonspecific imaging and negative cytology.
• Nephroureterectomy is a valuable diagnostic and therapeutic option for suspected renal pelvic tumors.
• Malignant lymphoma should be included in the differential diagnosis of renal pelvic masses.