Papillary Renal Cell Carcinoma Cytological-Histological Correlation and Diagnostic Pitfalls

Research Article

Austin J Clin Case Rep. 2016; 3(3): 1093.

Papillary Renal Cell Carcinoma Cytological-Histological Correlation and Diagnostic Pitfalls

Pinnamaneni R¹, Ahmad N¹, Khalil FK³, Bui MM4 and Henderson-Jackson EB3*

¹University of South Florida, USA

²James A Haley VA Hospital, USA

³Department of Anatomic Pathology, H. Lee Moffitt Cancer Center & Research Institute, USA

4Departments of Anatomic Pathology and Sarcoma, H. Lee Moffitt Cancer Center & Research Institute, USA

*Corresponding author: Evita B Henderson-Jackson, Department of Anatomic Pathology, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa FL 33612, USA

Received: May 03, 2016; Accepted: August 31, 2016; Published: September 05, 2016


The papillary variant of renal cell carcinoma has distinctive cytological, histological, and clinical features. There are a few studies describing its cytological features. We describe the cytological and correlating histological features of two cases of papillary renal cell carcinoma, type-2. The smears revealed papillary-like clusters with relatively few single cells. The first case had tumor cells with scant to moderate cytoplasm, small to medium-sized nuclei, single and small nucleoli, and occasional nuclear grooves. Foamy macrophages were rare. Whereas, the second case had tumor cells that exhibited moderate cytoplasm with prominent vacuolization, larger nuclei with mild to moderate pleomorphism, and conspicuous nucleoli. Psammona bodies were numerous in one case while absent in the other. Subsequent histology and immunohistochemical stains confirmed the diagnosis of papillary renal cell carcinoma, type-2. Papillary renal cell carcinoma is a type of renal carcinoma that can often be accurately diagnosed by fine-needle aspiration. Cytologically recognizing this papillary tumor is important in the clinical management of patients.

Keywords: Papillary; Renal cell carcinoma; Fine needle aspiration


Papillary renal cell carcinoma (PRCC) is a rare type of renal malignancy representing 7%-15% of renal carcinomas [1,2]. By histology, PRCC is defined as a malignant epithelial tumor of the kidney with a minimum of 50% papillary architecture. Delahunt and Eble [3] reported the existence of two subtypes of PRCC with distinct morphologic features. PRCC type-1 is composed of papillae covered by a single or double layer of small cells with scanty, pale cytoplasm. The cells possess small ovoid nuclei with inconspicuous nucleoli. PRCC type-2 is made up of papillae covered by cells with large spherical nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm arranged in a pseudostratified manner [3].

The prognosis of patients with PRCC differs from that of patients with other variants of renal cell carcinoma. Papillary renal tumors are not as aggressive as renal cell carcinoma, clear cell type, but PRCC type-2 tend to be more aggressive and thus carry a worse prognosis than type-1 PRCC [2-5]. Fine-needle aspirations (FNA) of renal masses are performed to assess patient management which can result in resection if appropriate. Thus, the distinction of a specific variant of renal carcinoma may be crucial to the patient outcome. Recognition of pertinent cytological features of PRCC will allow for accurate diagnosis and the ability to differentiate other primary renal neoplasms and metastatic papillary tumors from PRCC. There have been a few reports describing the FNA diagnosis of PRCC [6-8]. In this report, we describe two cases of papillary renal cell carcinoma.

Materials and Methods

Two cases of papillary renal cell carcinoma were reviewed. (Case 1) Specimen was obtained by ultrasound guided fine-needle aspiration (FNA) biopsy using 22-gauge needle. (Case 2) Specimen was obtained by CT-guided FNA biopsy using 22-gauge needle. Both air-dried and ethanol-fixed smears were prepared. The air-dried specimens were stained with Diff-Quik and the ethanol-fixed slides were stained with Papanicolaou method. Cell blocks were made and fixed in formalin and embedded in paraffin. Sections were cut (5 um) and stained with hematoxylin and eosin. Additional sections were cut from the cell block material for immunohistochemical stains. Appropriate positive and negative controls were used.

Case 1

A 59 year-old gentleman presented with a 2.6 cm hyperdense left renal mass. Additional CT scan findings showed a 5.1 cm left para-aortic soft tissue mass and a 1.4 cm enlarged right paratracheal lymph node. The patient stated that he had increased frequency with urination at night. He denied any abdominal pain.

A FNA of the left renal mass and the left para-aortic soft tissue mass was performed. Cytologic smears were cellular and composed of numerous three-dimensional papillary groups of cells, as well as, single cells in the background (Figure 1a). The malignant cells demonstrated minimal-mild nuclear pleomorphism. Rare small nucleoli and occasional nuclear grooves were noted. The tumor cells had scant-to-moderate amount of cytoplasm with occasional cytoplasmic vacuolization. Numerous psammoma bodies were present (Figure 1b). Foamy macrophages were seen in the background. Based on these findings, the diagnosis of papillary renal cell carcinoma was rendered. Immunohistochemical stains done on the cell block were positive for cytokeratin 7, AMACR, and vimentin (Figure 2). In addition, the tumor was negative for CD10 and cytokeratin 20. The cytologic smears from the left para-aortic soft tissue mass demonstrated similar findings.