Dear Editor, The mucinous tubular and spindle cell carcinoma of the kidney (MTSCC-K) is an extremely rare subtype of renal cell carcinoma that accounts for <1 % of all renal tumors. Generally, MTSCC-K grows slowly and is indolent. Previous studies have argued that the degree of malignancy and metastasis of MTTSCC-K is low and that most pa- tients have a good prognosis after radical nephrectomy.2 However, a growing body of literature has found that not all MTSCC-K cases present with indolent growth, and some patients present with local recurrences and lymph node and distant metastases after surgery.