Bump Appeared On the Scalp After Chemo Treatments

My patient had adenocarcinoma of the colon and now has adenocarcinoma in the right colon. She has completed 6 of her 8 chemotherapy treatments. She had a bump that appeared on the top of her head in the last month. It does not itch, hurt or produce any symptoms.She picks it but nothing comes out. Suddenly appeared. Differentials for this diagnosis?

Thank you

You sound like a doctor asking this question. There could be some inflammation following the hair loss from chemo, but I would want to know what the bump looks and feels like, its size, and the presence of any lymph nodes in the neck, etc.