Three cases of oral squamous cancer associated with leukocytosis, hypercalcemia, or both

Three examples of malignant neoplasms primary to the oral cavity and associated with paraneoplastic syndromes are presented. The first case is a squamous cell carcinoma of the maxilla associated with leukocytosis. The second case is a mandibular squamous cell carcinoma associated with hypercalcemia in the absence of bony metastases. The third case is a squamous cancer of the tongue that metastasized to the lumbar vertebrae and right second rib and was associated with both hypercalcemia and leukocytosis. There was no evidence of acute infection or leukemia that could be expected to account for leukocytosis. Hypercalcemia in the second case was defined as humoral hypercalcemia of malignancy by biochemical and clinical evaluations. To our knowledge, this is the first definitive report of a carcinoma primary to the oral cavity associated with humoral hypercalcemia of malignancy. In each case, the severity of hypercalcemia, leukocytosis, or both very closely correlated with tumor growth. Surgical excision of the tumors or regression of tumor mass due to aggressive anticancer drug administration resulted in decreases in leukocyte number, serum calcium level, or both. In contrast, recurrence or regrowth of tumors induced further development of hypercalcemia, leukocytosis, or both. It is therefore likely that humoral factors released by these oral carcinomas are responsible for the hypercalcemia, leukocytosis, or both.