Novel Insights from Clinical Practice DOI: 10.1159/000326940 Received: January 6, 2011 Accepted: February 21, 2011 Published online: July 22, 2011 Case Report of Renal Cell Carcinoma Diagnosed in Voided Urine Confirmed by CD10 Immunocytochemistry Sanjivani B. Dubal a Saleem Pathuthara a Dulhan Ajit a Santosh Menon b Shubhada V. Kane a Departments of a Cytopathology and b Pathology, Tata Memorial Hospital, Mumbai, India E s t a b l i s h e d Fa c t s Not every carcinoma detected in urine cytology is necessarily a transitional cell carcinoma. Renal cell carcinoma can be suspected by urine cytology based on cytomorphology and can be confirmed later in a clinicoradiological context. However, a prospective diagnosis of renal cell carcinoma in urine cytology is rare. Hence this case report. The underdiagnosis of renal cell carcinoma in urine is probably due to minimal cytological atypia and its close resemblance to degenerative urothelial cells. In addition, obscuring hemorrhage and inflammation can lead to screening and interpretative error (false negative). N ove l I n s i g h t s A specific constellation of cytomorphologic features like papillary clusters with bland nuclear features and vacuolated cytoplasm in conjunction with the appropriate clinical setting favors the diagnosis of renal cell carcinoma in urine cytology. Use of immunocytochemistry on smears (destained/restained) with CD10 antibody can confirm the diagnosis. Accurate diagnosis of renal cell carcinoma on urine cytologic examination can avoid further investigations and thereby minimize the cost. Key Words Renal cell carcinoma Urine Cytology Immunocytochemistry CD10 Abstract Background: Preoperative diagnosis of renal cell carcinoma (RCC) by exfoliative urine cytology is difficult, as infiltration of RCC into the pelvicalyceal system is uncommon. The ex- foliation of RCC cells in urine is a rare phenomenon and when it does occur, it is likely to be missed. Cytologic examination of the urine coupled with ancillary immunocytochemistry can clinch the diagnosis leading to appropriate clinical management. Case: A 50-year-old man presented with complaints of hematuria and abdominal pain of 6 months duration. Ultrasonographic examination of the abdomen and pelvis showed a well-defined mass lesion in the upper pole of the left kidney, suggestive of neoplastic etiol- Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com 2011 S. Karger AG, Basel 0001 5547/11/0554 0372$38.00/0 Accessible online at: www.karger.com/acy Correspondence to: Mr. Saleem Pathuthara Department of Cytopathology, Tata Memorial Hospital Parel, Mumbai, Maharashtra 400 012 (India) Tel. +91 22 2417 7000, ext. 4356 E-Mail saleempathuthara @ gmail.com
ogy. In the given clinical context of renal mass, urine cytology was suggestive of RCC and biopsy confirmation was suggested. One cytology smear subjected to immunocytochemistry with anti-cd10 antibody which showed strong diffuse cytoplasmic positivity in these cells confirmed the diagnosis of RCC. Subsequently, fine needle aspiration cytology of the kidney mass was reported as RCC. Conclusions: RCC has distinct cytologic features that facilitate a diagnosis in urine in an appropriate clinical and radiological context. Their recognition in the urine smear is important to avoid costly and invasive modalities like image-guided needle biopsy. Copyright 2011 S. Karger AG, Basel Renal cell carcinoma (RCC) is the most common form of malignancy arising in the adult kidney and accounts for 90 95% of all kidney cancers. Cytologic examination of voided urine is a simple, noninvasive, cost-effective diagnostic modality used to detect any abnormal cells that exfoliate from the urinary tract into the bladder. Traditionally, transitional cell carcinoma (TCC) of the lower urinary tract, i.e. the bladder and ureter, is diagnosed by urine cytology. Cytological findings of papillary RCC obtained from fine needle aspiration or imprint smears have been reported previously [1 4]. To our knowledge, only one case report on papillary RCC diagnosed in voided urine in a patient with renal calculus [5] has been published. devoogt et al. [6] have elaborately described the differential cytomorphological features of RCC, histiocytes and degenerating urothelial cells in urine smear stained by May- Grünwald-Giemsa stain way back in 1977. We report a (rare) case of RCC detected by urine cytology in a patient presenting with renal mass and hematuria and confirmed by immunocytochemistry (ICC) of the destained smears. C a s e R e p o r t Fig. 1. CT scan showing a well-defined solid lesion in the upper pole of the left kidney, measuring 32 mm in craniocaudal, 30 mm in transverse and 34 mm in anteroposterior dimensions. A 50-year-old man with complaints of hematuria and abdominal pain attended our urology outpatient department in 2009. On a computerized tomography scan of the abdomen and pelvis, a well-defined solid lesion was seen in the upper pole of the left kidney, measuring about 32 mm in craniocaudal, 30 mm in transverse and 34 mm in anteroposterior dimensions ( fig. 1 ). No calcification or calculus was identified. The urinary bladder, seminal vesicles and prostate did not show any abnormality. Minimal ascitis and bilateral pleural effusions were present, which was not tapped. Renal function tests showed elevated levels of serum urea (179 units/ml) and serum uric acid (13.5 mg/dl), whereas serum creatinine was within the normal range (3.9 mg/dl). Urine cytology examination was also performed for the work-up in view of hematuria. About 20 ml of a random sample of urine was collected and submitted to cytology. Grossly, the sample was deep red in color due to hemorrhage. Centrifugation was done at 2,000 rpm for 10 min. The supernatant was discarded and the sediment was picked up with the help of a cotton-tipped applicator stick and smears were prepared by rolling the swab stick on albuminized glass slides. The smears were fixed in 100% methanol and stained by the standard Papanicoloau method. Cytologic Findings The smears were cellular and showed a dual population of cells comprising benign urothelial cells and large atypical cells. The atypical epithelial cells occurred singly and in clusters with papillary architecture. These cells showed characteristic abundant clear to foamy cytoplasm and well-defined cytoplasmic borders as well as a slightly high nuclear cytoplasmic ratio ( fig. 2, 3 ), and the nuclei were round and eccentrically placed and showed vesicular chromatin, a thick nuclear membrane with single or multiple small nucleoli. In addition to atypical cells, smears showed singly occurring benign urothelial cells in the background. These cells showed abundant dense cytoplasm and central vesicular small nuclei. The chromatin was finely granular with a smooth nuclear membrane and inconspicuous nucleoli. The N/C ratio was low. These urothelial cells did not show any cytological or architectural atypia. The cytomorphology of abnormal cells led to suspicion of RCC which matched with the clinicoradiological findings. In the given clinical context of the renal mass and no radiological abnormality in the bladder, urine cytology was suggestive of conventional RCC, and biopsy conformation was advised. Im m u n o c y t o c h e m i s t r y One of the cytology smears was destained and subjected to ICC with anti-cd10 (common acute lymphocytic leukemia anti- Renal Cell Carcinoma Diagnosed in Voided Urine 373
2 3 Fig. 2, 3. Voided urine. Cluster of RCC cells with abundant foamy cytoplasm, vesicular eccentric nuclei, fine powdery chromatin and nucleoli. Papanicoloau stain.! 400. in Tris buffer. Primary antibody CD10 (Biocare, dilution 1: 40) was applied for 1 h and washed in Tris buffer. Polymer technology was used as secondary detection system, and after polymerizing for 30 min, 3-3 -diaminobenzidine trichloroacetic acid was applied as chromogen, counterstained with hematoxylin for 5 min and then mounted in DPX. The atypical cells showed strong diffuse cytoplasmic positivity with CD10, which confirmed the diagnosis of RCC ( fig. 4 ). Final Diagnosis Following urine cytology, an ultrasound-guided aspiration from the renal mass was performed. The aspirate was cellular and showed many clusters of atypical cells arranged in sheets and papillary structures. The cells showed central small round nuclei, fine granular chromatin, inconspicuous nucleoli and abundant foamy cytoplasm ( fig. 5, 6 ). These features were consistent with the diagnosis of conventional RCC. Fig. 4. Voided urine. Strong diffuse cytoplasmic immunoreactivity with CD10 antibody in the destained smear confirms the cytologic diagnosis. Treatment and Follow-Up The patient was advised with left radical nephrectomy and, according to his request, the same was planned to be performed at his native place. gen) antibody by using 3-3 -diaminobenzidine trichloroacetic acid as the chromogen. First, the cover slip was removed by immersing the slide in xylene overnight. Subsequently, the slide was kept in 95% ethanol for 1 h and destained in acid alcohol (1% HCl in 70% ethanol) for 30 s. After thorough washing in water, the excess water was blotted. The endogenous peroxidase activity was quenched using 3% H 2 O 2 in methanol for 10 min and washed in running tap water. Antigen retrieval was done by microwaving at low power (180 W for 2 min). After cooling, the smear was washed Discussion RCC represents 80 90% of all malignant tumors of the kidney and 2% of all cancers in adults [7]. It is most common in the late middle age, from the 5th to the 7th decade, and males are affected more often than females. Hematuria and dull abdominal pain are the main features of clinical presentation. 374 Dubal /Pathuthara /Ajit /Menon /Kane
5 6 Fig. 5, 6. Fine needle aspiration smears showing clusters of atypical cells with small round nuclei, finely granular chromatin, inconspicuous nucleoli and abundant foamy cytoplasm. Papanicoloau and Giemsa stain.! 400. Detection of tumor cells in the urine is not possible until the cells exfoliate into the urine in large numbers. Cancer cells that arise from the transitional epithelium lining the urinary tract exfoliate directly into the urine. The cells are carried to the bladder and voided in the urine. Thus, the cells of TCC arising from the pelvicalyceal system, ureter or urinary bladder can be detected easily on urine cytologic examination. On the other hand, intrarenal tumors, lying within the renal cortex [8], do not exfoliate cells into urinary passages until they have penetrated the wall of the structures (e.g. the renal pelvis) en mass. Most RCC clinically present with gross hematuria in a later stage. Thus, the scanty exfoliated tumor cells are easily missed on casual screening as they are masked due to hemorrhage. Thus, diagnosis of RCC on urine cytologic examination is uncommon. In addition, degenerative changes [9] in the epithelial cells in urine samples are very common due to the alkaline ph. Hence, at times, it is difficult to pick up the stray degenerating tumor cells and interpret them appropriately. As a result of all these factors, a high degree of sensitivity in detecting RCC in the urine is not expected. Therefore, a high index of suspicion is necessary in such a clinical setting, particularly in smears with hemorrhagic background. Differential diagnoses include reactive and degenerating urothelial cells, foamy macrophages, papillary TCC, as well as colonic adenocarcinoma. Reactive urothelial cells show enlarged nuclei, prominent nucleoli and abundant dense cytoplasm with a low N/C ratio. Degenerating urothelial cells show vacuolated cytoplasm with degenerative nuclear changes. However, these cells depict urothelial morphology. Chromatin and nuclear membrane abnormality associated with cancer cells is not evident. devoogt et al. [6] have highlighted the presence of central nuclei, finely vacuolated cytoplasm, a low N/C ratio and relatively large nucleoli in a monomorphic population of cells as characteristic features of RCC. In papillary TCC, papillary clusters of cells with variable sizes and shapes are seen [10]. Also, TCC cells show obvious nuclear enlargement, a high N/C ratio, nuclear hyperchromasia, irregular nuclear border and dense cytoplasm. On the other hand, papillary RCC will show abundant foamy cytoplasm, eccentric round nuclei with conspicuous nucleoli, a thick nuclear membrane and vesicular chromatin besides the papillary architecture. Foamy macrophages with intracytoplasmic hemosiderin and nuclear grooves in the tumor cells were not seen in the smears which are usually observed in the fine needle aspiration cytology of papillary RCC [11]. Foamy macrophages are a close mimic of RCC cells. The pale reniform nuclei with cytoplasmic phagocytosis help in their recognition and differentiation from RCC cells. In colonic adenocarcinoma, tubular or elongated clusters of large cells with elongated hyperchromatic and pseudostratified nuclei, coarse chromatin and vacuolated or clear cytoplasms are noted [10]. Primary kidney tumors are of varied histological types. RCC, particularly the clear cell type, is the most common primary tumor. Going through the literature, there is only one case report [5] having detected RCC in Renal Cell Carcinoma Diagnosed in Voided Urine 375
voided urine cytology; however, we came across one article which reported collecting duct carcinoma in urine cytology [12]. In this case, urine cytology showed cellular abnormalities that were not typical of TCC, yet were suspicious of neoplastic etiology. It is difficult to assess the sensitivity and specificity of urine cytologic examination in recognizing tumors of the upper urinary tract, particularly RCC due to small number. The role of ICC in confirming the diagnosis of RCC has been well worked out. The use of monoclonal antibodies to RCC and CD10 in differentiating clear cell carcinoma of the kidney from chromophobe cell carcinoma, TCC or oncocytoma has been documented by Yang et al. [13] and Avery et al. [14]. TCC is the commonest histological type of tumor of the urinary tract, usually arising from the bladder, and less commonly, from the pelvis and ureters. These tumors can be easily detected by urine cytology, as the cells are readily exfoliated into urine. The tumors of the non- TCC type include mainly RCC which seldom exfoliates cells into urine, to be detected by urine cytology. Therefore, correlation with imaging findings is essential for the proper interpretation of atypical cells detected in the urine which do not look like TCC cells. The possibility of RCC should be considered as one of the differentials in such cases. If in doubt as to whether it is RCC or TCC or degenerating urothelial cells, it is recommended to do an ICC on smears using CD10, CK7, EMA PG3 and HMWCK markers. Urine cytology is a simple, cheap, cost-effective, noninvasive investigation. It may be helpful to identify the origin of cancer cells with reasonable certainty and thus contribute to the final diagnosis. However, it is important to be familiar with the cytological picture of RCC so as to avoid screening and interpretative errors and increase the diagnostic utility in urine cytology. This case highlights the scope of primary diagnosis of RCC in urine cytology. Preoperative diagnosis of RCC in urine helps in appropriate treatment planning, including surgery and targeted therapy. References 1 Granter SR, Perez-Atayde AR, Rensahaw AA: Cytologic analysis of papillary renal cell carcinoma. Cancer Cytopathol 1999; 94: 303 309. 2 Flint A, Cookingham C: Cytologic diagnosis of the papillary variant of renal cell carcinoma. Acta Cytol 1997; 31: 325 329. 3 Dekmezian R, Sneige N, Shabb N: Papillary renal cell carcinoma: fine needle aspiration of 15 cases. Diagn Cytopathol 1991; 7: 199 203. 4 Renshaw AA, Lee KR, Madge R, Granter SR: Accuracy of fine needle aspiration in distinguishing subtypes of renal cell carcinoma. Acta Cytol 1997; 41: 987 994. 5 Kawakami H, Hoshida Y, Hanai J: Voided urine cytology of papillary RCC and renal calculus. Acta Cytol 2001; 45: 771 774. 6 devoogt HJ, Rathert P, Beyer-Boon ME: Urinary Cytology: Phase Contrast Microscopy and Analysis of Stained Smears. Berlin, Springer, 1977, pp 39, 153. 7 Garnick, MB, Riche JP: Renal neoplasia in the kidney; in Brenner BM, Recher FC Jr (eds): The Kidney, ed 3. Philadelphia, Saunders, 1986, pp 1533 1550. 8 Foot NC, Papanicoloau GN, Holmquist ND, Seybolt JF: Exfoliative cytology of urinary sediments: a review of 2,829 cases. Cancer 1958; 11: 127 137. 9 Koss LG: Tumors of the urinary tract and prostate in urinary sediment; in Koss LG: Diagnostic Cytopathology and Its Histopathologic Bases, ed 4. Philadelphia, Lippincott, 1992, p 904. 10 Koss LG: Diagnostic Cytology and Its Histologic Bases, ed 4. Philadelphia, Lippincott, 1992, pp 966 967. 11 Granter SR, Perez-Atayde AR, Renshaw AA: Cytologic analysis of papillary renal cell carcinoma. Cancer Cytopathol 1999; 94: 303 309. 12 Fallick ML, et al: Collecting duct carcinoma presenting as upper tract lesion with abnormal urine cytology. Diagn Cytopathol 1997; 16: 258 261. 13 Yang B, Ali SZ, Rosenthal DL: CD10 facilitates the diagnosis of metastatic RCC from primary adrenal cortical neoplasm in adrenal fine-needle aspiration. Diagn Cytopathol 2002; 27: 149 152. 14 Avery AK, Beckstead J, Rensahaw AA, Coreless CL: Use of antibodies to RCC and CD10 in the differential diagnosis of renal neoplasm. Am J Surg Pathol 2000; 24: 203 210. 376 Dubal /Pathuthara /Ajit /Menon /Kane