Granulocyte colony-stimulating factor-producing squamous cell carcinoma of the lower gingiva: a case report.

The present study summarizes our experience in treating a patient with a suspected granulocyte colony-stimulating factor (G-CSF)-producing squamous cell carcinoma (SCC) of the lower gingiva, which is a rather rare entity. A 56-year-old woman underwent surgical excision of palate leukoplakia in 1996. In 2009, however, a leukoplakic superficial tumor was detected in the lower left gingiva, for which the patient underwent gingivectomy. This was subsequently diagnosed as SCC. The patient also underwent superselective arterial injection chemotherapy combined with radiotherapy, after local recurrence was observed. The patient was subsequently found to have bone metastasis. After chemotherapy combined with radiotherapy, the patient underwent segmental resection of the lower left jaw, left supraomohyoid neck dissection, and lower jaw reconstruction using titanium plates. Resection of the left femoral tumor and left total knee replacement were also performed. Computed tomography scan performed 1 month after the surgeries revealed multiple lung, liver, spine, and subcutaneous metastases. The patient also exhibited a sudden increase in her white blood cell (WBC) count and a fever that could not be alleviated, despite treatment with antibacterial drugs. A G-CSF-producing tumor was therefore suspected. Serum G-CSF level was high at 250 pg/ml. The patient's WBC count increased to 32 × 10(3)/ml and her general condition suddenly deteriorated, and she died as a result of multiple organ failure. A final diagnosis of G-CSF-producing SCC of the lower gingiva was made based on the patient's clinical course.