A 53-Year-Old Male Smoker With Advanced Oral Squamous Cell Carcinoma Associated With Paraneoplastic Leukemoid Reaction.

BACKGROUND Paraneoplastic leukemoid reaction is characterized by leukocytosis or a significant increase in white blood cells (WBC) equal or greater than 50 000 cells/µL and is commonly associated with high-grade carcinomas, particularly squamous cell carcinoma. Paraneoplastic leukemoid reaction has a poor prognosis and is a diagnosis of exclusion. This report describes the case of a 53-year-old male patient with advanced oral squamous cell carcinoma associated with paraneoplastic leukemoid reaction and hypercalcemia. The patient was a current smoker with a 30-pack-year history. CASE REPORT In this report, we describe a case of clinical stage IVA (T4aN2cM0) keratinized, well-differentiated squamous cell carcinoma of the oral cavity associated with paraneoplastic leukemoid reaction and hypercalcemia. The patient initially had an extremely high leukocyte count of 151 400 cells/µL (reference range, 4500 to 11 000 cells/μL), and a high serum calcium level of 12 mg/dL (reference range, 8.8 mg/dL to 10.4 mg/dL). Despite intensive medical treatment and concurrent chemoradiotherapy, the patient died from aggressive tumor growth and the effects of blood hyperviscosity 54 days after the initial presentation. CONCLUSIONS Oral squamous cell carcinoma associated with paraneoplastic leukemoid reaction and hypercalcemia is quite rare and has a very poor prognosis. Therefore, it is crucial for clinicians to be aware of this condition. To optimize treatment decisions and improve patient outcomes, a multidisciplinary approach is recommended for managing such a complex case.