Rapid Hair Depigmentation in Patient Treated with Pazopanib

The document reported a unique case of rapid hair depigmentation in a 62-year-old patient treated with pazopanib for metastatic renal cell carcinoma. Unlike the gradual hair color changes typically associated with pazopanib, this patient experienced an overnight change to white hair and eyebrows after a few weeks of therapy. This phenomenon, known as canities subita, had not been previously documented in relation to tyrosine kinase inhibitors (TKIs) like pazopanib. The patient also experienced other side effects, including hypertension and gastrointestinal issues, but showed significant regression of pulmonary metastases, suggesting that the depigmentation might be a predictor of therapy success. The exact mechanism behind the rapid depigmentation remained unclear, though it was hypothesized to involve a combination of TKI effects, psychological stress, and acute pain. Further research was needed to understand this phenomenon better.