Paraneoplastic leukemoid reaction as marker for transitional cell carcinoma recurrence

A case of a 78-year-old man with transitional cell carcinoma and a paraneoplastic leukemoid reaction. The leukocytosis was present at the diagnosis of carcinoma. It dissipated with complete tumor resection, was absent when a surveillance computed tomography scan showed no evidence of recurrence at 6 months, and had returned with tumor recurrence at 8 months. This case demonstrates that a paraneoplastic leukemoid reaction can be used as a tumor marker in cases of transitional cell carcinoma when a leukemoid reaction is found at presentation.