ACTA FAC MED NAISS 2020;37(1):79-86

Case report

UDC: 616.61-006.6-036
DOI: 10.5937/afmnai2001079P

 

Rhabdoid Differentiation in Different Types of Renal Cell Carcinoma:

A Report of Two Cases and Literature Review

 

Milena Potić-Floranović1, Ana Ristić-Petrović2, Filip Veličković3, Milan Potić4,
Tanja Džopalić1, Ljubinka Janković-Veličković2

 

 

1University of Niš, Faculty of Medicine, Scientific Research Center for Biomedicine, Niš, Serbia
 2Center for Pathology and Pathological Anatomy, Clinical Center Niš, Niš, Serbia
 3Nuclear Medicine Center, Clinical Center Niš, Niš, Serbia
 4Urology Clinic, Clinical Center, Niš, Serbia

 


summary

 

    Rhabdoid morphology is a rare differentiation pattern that can occur in any type of renal cell carcinoma. In approximately 5% of renal tumors, a variable percent of rhabdoid cells can be seen. Even though these cells resemble rhabdomyoblasts, they are large, with large eccentric nuclei and prominent nucleoli; they have different immunophenotype and ultrastructural features. Tumors with rhabdoid differentiation are classified as grade 4, they have aggressive clinical behavior and poor prognosis. We present two cases of 83-year-old and 60-year-old male patients. Samples of both patients were obtained after radical nephrectomy. In the first patient, papillary renal cell carcinoma was verified, and its phenotype was immunohistochemically demonstrated. Cells with papillary morphology were mixed with rhabdoid cells arranged in sheet-like, pseudotubular and organoid structures. The second patient had the incidentally discovered clear cell renal cell carcinoma with rhabdoid differentiation, together with adenocarcinoma of the colon. Histopathological evaluation showed cells that were typical for clear cell carcinoma and large non-cohesive rhabdoid cells as well. Giant, bizarre multinuclear cells were also noted. Homogenous rhabdoid morphology accounted for about 60% of the tumor.
             Rhabdoid differentiation in renal cell carcinoma is a high-grade morphological feature. It is associated with poor outcome, and distant metastases are commonly present at the time of diagnosis. In order to clarify the significance of this type of divergent differentiation on prognosis, future treatment options and outcome of the disease, further analysis of a larger number of cases is necessary.

 

Key words: renal cell carcinoma, rhabdoid differentiation, prognosis