How do you diagnose an oncocytoma?
Clinicians can confirm the diagnosis of oncocytoma with immunohistochemistry.
The most common stain used is cytokeratin 7, which is minimally positive and limited to scattered individual cells or small clusters.
AMACR may be positive in low intensity.
Oncocytoma should have membranous positivity for CD117.Aug 29, 2022.
What are the histologic features of renal oncocytoma?
Highly cellular (Br J Urol 1988;61:534, Acta Cytol 1980;24:355, Cancer 2001;93:390)Rounded nests (on cell block)Cohesive fragments with discohesive cells.Abundant eosinophilic and uniformly granular cytoplasm.Round nuclei with medium sized nucleoli (grade 2)Mitosis absent and necrosis absent or very infrequent..
What are the microscopic features of oncocytoma?
Oncocytomas typically contain edematous myxoid or hyalinized stroma, often resulting in at least some areas with nests and tubular structures dispersed in this stroma.
Clear cytoplasm may also be focally present, typically in the area of the central scar..
What is a oncocytoma?
Oncocytoma is a benign solid tumor that arises from the proximal renal tubule.
Most are seen in men in their 60s.
Unfortunately, no imaging test can reliably differentiate these benign tumors from RCC.
Treatment is surgical..
What is cytology of renal oncocytoma?
The cytology consists of uniform population of large eosinophilic granular cells that are either isolated or form small, loose aggregates.
The cell borders are well defined and nucleoli are quite small and round..
What is oncocytoma renal cytology?
Microscopically, renal oncocytomas appear well-circumscribed.
The mass is composed of nests and tubular structures line by round to polygonal cells with abundant granular eosinophilic cytoplasm.
The cells have uniform nuclei with prominent central nucleoli..
What is the histology of the oncocytoma?
Histologically, oncocytomas are composed of nests, cords, and tubular structures made up of large polygonal cells with a brightly eosinophilic, granular cytoplasm (Figure 2).
Nuclei are usually small and uniform; mitotic figures are rare or absent.
The cells are rich in mitochondria..
- Eosinophilic-type chromophobe RCC shows diffuse cytoplasmic staining with Hale's colloidal iron, which is negative in oncocytoma.
Lack of intracytoplasmic glycogen and mucin, and nonreactivity to RCC marker, can be helpful in distinguishing oncocytomas from RCCs. - Oncocytomas typically contain edematous myxoid or hyalinized stroma, often resulting in at least some areas with nests and tubular structures dispersed in this stroma.
Clear cytoplasm may also be focally present, typically in the area of the central scar.
