Rapid hair depigmentation in patient treated with pazopanib.

Pazopanib is multitargeted tyrosine kinase inhibitor used for the treatment of metastatic renal cell carcinoma. Hair colour change is a common side effect of pazopanib therapy which usually develops gradually during few months of therapy. We report a case of the patient who developed multiple pazopanib side effects followed by rapid overnight hair and eyebrow depigmentation after only few weeks of therapy. In our research, we found no literature data of rapid loss of hair pigment due to therapy with any of listed multitargeted tyrosine kinase inhibitors. To the best of our knowledge, this is the first such case being reported. We presume that summation of different mechanisms probably led to rapid hair depigmentation. Considering the fact that pazopanib treatment was very effective in our patient, this side effect could be a good predictor of therapy success, although it presents very stressful event for patient and his family.