Giant cell carcinoma of the lung with hypertrophic pulmonary osteoarthropathy as a paraneoplastic syndrome: a case report

Background Hypertrophic pulmonary osteoarthropathy is a rare syndrome characterized by a triad that includes periostitis, digital clubbing, and painful arthropathy of the large joints, especially large joints in the lower limbs with lung cancer. Herein we describe a case of a giant cell carcinoma of the lung with hypertrophic pulmonary osteoarthropathy as a paraneoplastic syndrome. The tumor was successfully resected, and complete remission of the syndrome was achieved after surgery. Case presentation A 48-year-old man with right fingers and bilateral ankle arthralgias was referred to our hospital. These arthropathies were painful and refractory to the oral administration of several non-steroidal anti-inflammatory drugs; thus, oxycodone hydrochloride hydrate was prescribed. Additionally, the fingers and toes had a clubbed appearance and the tubular bones were shown as double lines on radiographs of both arms and legs, indicating periosteal thickening. A 45-mm mass-like shadow was present on the right upper-to-middle lung field on the chest x-ray, which was confirmed to be a mass in the upper lobe of the right lung on the chest CT scan. An abnormal uptake was observed in the area of the mass on the FDG-PET scan; the standardized uptake value maximum was 11.8. The histologic diagnosis of a bronchoscopic biopsy was an undifferentiated carcinoma, and the clinical diagnosis was non-small cell lung cancer. The clinical stage was c-T2bN0M0 with paraneoplastic syndrome as a hypertrophic pulmonary osteoarthropathy. A right upper lobectomy with an S6 partial resection adjacent to the upper lobe of the right lung and an ND2a-2 lymph node dissection was performed. The postoperative course was uneventful. The pathologic diagnosis was a giant cell lung carcinoma, which was classified as p-T3 (52 mm in diameter) N0M0, stageIIB. A gradual decrease in arthritic pain was observed from the first operative day. No anodyne, including oxycodone, was required approximately 2 months after surgery. No tumor or paraneoplastic syndrome recurrence was observed 2 years postoperatively. Conclusions Hypertrophic pulmonary osteoarthritis may occur as a secondary manifestation of lung malignancies. Thus, the paraneoplastic syndrome should be considered in such cases.