合併難染性腎細胞癌及腎結石的個案討論
潘 岳1、李良明1、溫玉清1、蕭志豪1 
台北市立萬芳醫院 泌尿科1
Chromophobe renal cell carcinoma in the patient with renal stone
A case report and literature review
Pan Yueh1, Liang-Ming Lee1, Yu-Ching Wen1, Chi-Hao Hsiao1 
Division of Urology, Wan Fang Medical Center, Taipei Medical University1, Taipei, Taiwan

Case Presentation: This 59 year-old female patient has history of human immunodeficiency virus infection and atrial fibrillation. Staghorn right renal stones with hydronephrosis and a 5cm tumor mass lesion at right kidney with internal calcification were noted on CT scan (Figure.1) which suspect renal cell carcinoma. After discussion with the patient and the family, laparoscopic right radical nephrectomy was performed. The final pathology report was chromophobe renal cell carcinoma (Figure.2) with IHC study CK7 positive and CA9 negative (Figure.3).  
Discussion: Renal cell carcinoma arises from the renal parenchyma. It accounts for approximately 2 to 3% of all adult malignant cancer. The main symptoms are flank pain, gross hematuria, and a palpable abdominal mass called the classic triad. However, these symptoms usually indicate advanced renal cell carcinoma.[1] 
  Primary renal squamous cell carcinoma affects less than 1% of all urinary tract neoplasms. It occurs more often in the urethra and urinary bladder than in the renal pelvis in males. This cancer is highly aggressive and usually progresses at the first diagnosis, leading to a poor prognosis.[2.3] 
  Long-lasting renal stone is a risk factor of squamous cell carcinoma of the renal pelvis. It is aggressive and usually diagnosed at advanced stages with a poor prognosis. When complicated with kidney stones, renal squamous cell carcinoma are usually missed and underestimated in clinic. Careful inspection of CT images and histopathology examination remarkably help to diagnose and stage renal squamous cell carcinoma. Although there are treatments for renal squamous cell carcinoma, the overall prognosis is still poor.[4]
  Chromophobe renal cell carcinoma makes up approximately 5% of all cases of renal cell carcinoma. This subtype of renal cell carcinoma was arise from the intercalated cells of the collecting ducts. This disease is challenging to diagnose and can share histologic similarities with benign oncocytomas using conventional evaluation or even be misclassified as the more common clear-cell type. Therefore, careful histologic attention is needed to appropriately capture these cases. Histologically, two variants are recognized: classic type and an eosinophilic variant. The classic type is more common and is characterized by large cells with pale chromophobe cytoplasm and a perinuclear halo or clearing. On the other hand, the tumor cells in the eosinophilic variant display a dense eosinophilic cytoplasm and perinuclear halos. [5] 
  After searching papers, we found that patients with chromophobe renal cell carcinoma and renal stone simultaneously is rare, so that we present this case.