Editorial Comment to A case of perirenal non‐specific lymphadenitis mimicking a solitary renal mass

To arrive at a definitive diagnosis of the rare condition of perirenal nonspecific lymphadenitis (PNSL), 1,2 it is necessary to exclude all the various benign diseases mimicking renal malignancy, such as tuberculosis, malacoplakia, and mycosis. [...]tumor specimens from biopsies or surgery should be appropriately prepared to investigate the clinical findings of all of these mimicking diseases. Primary renal lymphoma (PRL) has the poorest prognosis among the differential diagnosis of the lymphoid diseases. [...]minimally invasive lymph node resection needs to be planned in order to rule out lymphoma completely in cases where lymphatic tissue is detected in the preoperative needle biopsy of perirenal tumor. According to a recent study from the Surveillance, Epidemiology, and End Results (SEER) database, 3 the 5-year overall survival and cancer-specific survival rates of limited PRL (Stage I or II) are 61.6% and 72.9%, respectively.