Abstract
A 64-year-old man was admitted to our hospital because of an abnormal shadow on a chest X-ray. Computed tomography showed a mass in the right lower lobe and a nodule in the left upper lobe. Bronchoscopy revealed mucosal thickening at the bifurcation between left B6a and B6b+c. These lesions were diagnosed as triple lung cancer (well differentiated adenocarcinoma in right S10, poorly differentiated adenocarcinoma in left S1+2 and squamous cell carcinoma in situ the bifurcation between left B6a and B6b+c) by transbronchial biopsy. We treated the patient with anticancer drugs and radiotherapy. About 2 years after diagnosis, serum Ca and PTHrP levels were increased and be suffered consciousness disturbance. Biphosphonate was used to control the serum Ca level, but the patient died of hypercalcemia. Immunohistochemical staining using anti-PTHrP monoclonal antibody revealed PTHrP immunoreactivity in the cancer cells of well differentiated adenocarcinoma in right S10, but the cancer cells of poorly differentiated adenocarcinoma in left S1+2 and squamous cell carcinoma in the spur between left B6a and B6b+c did not have immunoreactivity. This case was considered to be a very rare case with triple lung cancer with hypercalcemia due to elevated PTHrP level.
