Chromophobe renal cell carcinoma (ChRCC) is a distinct subtype of kidney cancer that accounts for approximately 5-7% of all renal cell carcinomas.
ChRCC arises from the intercalated cells of the renal collecting duct system.
Generally has a better prognosis compared to clear cell and papillary RCC, with lower rates of metastasis and recurrence.
Tumor cells are large and pale with distinct cell borders
Characteristically pale, flocculent cytoplasm (either eosinophilic or clear).
The nucleus pften described as having a “raisinoid” or wrinkled appearance with perinuclear halos.
Hale’s colloidal iron stain is classically positive, which distinguishes it from oncocytoma.
Multiple chromosomal losses, particularly of chromosomes 1, 2, 6, 10, 13, 17, and 21 are present.
Generally lacks VHL gene mutations, unlike clear cell RCC.
Can be associated with Birt-Hogg-Dubé syndrome an inherited condition.
It is often detected incidentally on imaging.
It may present with hematuria, flank pain, or palpable mass.
Typically is a solid, well-circumscribed tumor.
Less aggressive behavior with 5-year survival rates >90% for localized disease
Primary treatment is surgical resection (partial or radical nephrectomy).
It has limited responsiveness to systemic treatments.
ChRCC is generally less responsive to immunotherapy and targeted therapies compared to clear cell RCC.
Immunotherapy in targeted therapy combinations demonstrate variable efficacy, although combinations of these agents currently represent the most promising therapeutic strategy.