Diagnostic difficulties in oncocyte-containing renal carcinoma

Area of Science:

• Nephrology
• Oncology
• Pathology

Background:

• Renal tumors present diverse histopathological features.
• Accurate diagnosis of renal neoplasms is crucial for appropriate patient management.
• Distinguishing benign oncocytomas from renal cell carcinoma can be diagnostically challenging.

Observation:

• Two cases of renal tumors with diagnostic difficulties are presented.
• Fine-needle aspiration biopsy in one case yielded only oncocytes, but histology revealed renal cell carcinoma.
• Computed tomography showed an inhomogeneous inner composition in the symptomatic tumor.

Findings:

• A mosaic pattern of renal cell carcinoma and oncocytes was observed in both cytologic and histologic specimens of the second, asymptomatic tumor.
• Histologic examination is essential to differentiate renal cell carcinoma from oncocytoma when cytology is equivocal.
• The presence of both cell types can complicate the diagnosis of renal neoplasms.

Implications:

• These cases underscore the importance of comprehensive histopathologic assessment for renal tumors.
• Awareness of mixed patterns in renal neoplasms can improve diagnostic accuracy.
• Further research into the molecular basis of these mixed patterns may offer new diagnostic avenues.