A case of G-CSF producing hypopharyngeal carcinoma:

Summary G-CSF (granulocyte colony-stimulating factor)-producing head and neck cancer is a rare entity. We experienced an advanced case of G-CSF-producing hypopharyngeal cancer, which simultaneously produced PTHrP (parathyroid hormone-related protein). The patient demonstrated marked granulocytosis, hypercalcemia, high serum levels of G-CSF and PTHrP, and diffuse accumulation of FDG in the spine. Thus, G-CSF-producing tumor was suspected. Soon after pharyngo-laryngo-esophagectomy, the number of granulocytes, and the levels of serum G-CSF, Ca, and PTHrP were normalized. By means of immunohistochemistry, the tumor was weakly stained with anti G-CSF monoclonal antibody. In addition, the bone marrow of the cartilage in the surgical specimen displayed strong hyperplasia, probably responding to the tumor-derived G-CSF. Taken together, this tumor was diagnosed as G-CSF-producing cancer. Without adjuvant therapy after surgery, the patient has been alive with no sign of tumor recurrence for more than 20 months. Given that the reported outcomes of patients with GSF-producing tumor are extremely poor, complete surgical resection appears to be the only effective treatment for this type of malignancy.