To analyze the clinical characteristics and methods of diagnosis and treatment of primary rare kidney neoplasms, in order to improve the understanding of primary rare kidney neoplasms.

The data of three cases of primary rare kidney neoplasms confirmed pathologically in the Seventh Affiliated Hospital of Sun Yat-sen University from May 2018 to September 2018 were analyzed retrospectively.

Case 1 was a 54-year-old woman, CT scan showed a large soft tissue mass in the left kidney and several enlarged lymph nodes around renal hilum in a routine check-up a week ago, laparoscopic radical left nephrectomy and lymphadenectomy were then conducted and the mass was pathologically proved to be mucinous tubular and spindle cell carcinoma, no recurrence or metastasis was observed during a 3-month follow-up. Case 2 was a 44-year-old man, presented with a 1-month history of left flank abdominal pain, MR examination revealed a huge space-occupying lesion in the left kidney. In consideration of inconvenient laparoscopic operation, open exploratory surgery was performed. During the operation the descending colon was discovered adhered to the lesion apparently, consequently radical left nephrectomy and partial resection of descending colon were conducted, and the histopathology was proved to be carcinosarcoma. Local relapse and extensive intraperitoneal metastasis were observed a month later, auxiliary chemotherapy with paclitaxel combined doxorubicin and targeted therapy with apatinib were executed according to oncologist’s advices, no further progression was observed till now. Case 3 was a 70-year-old man, presented with left flank pain and gross hematuria for three months, CT scan displayed irregular low-density focus in the upper pole of the left kidney and multiple retroperitoneal enlarged lymph nodes. Laparoscopic radical left nephrectomy and lymphadenectomy were carried out and the histopathology was unexpectedly proved to be high grade invasive urothelial carcinoma, the further nephroureterectomy was recommended but the patient refused it, neither recurrence nor metastasis was observed during a 6-month follow-up.

The clinical symptoms and imaging manifestations of primary rare kidney neoplasms are frequently lack of specific and easily to be misdiagnosed, more attention should be paid to distinguish from other diseases. Radical excision is the main therapeutic method, some types of neoplasms have a poor prognosis and close follow-up is essential, auxiliary radiotherapy, chemotherapy or targeted therapy should be performed postoperatively as early as possible if it is necessary.