Giant cell tumors of bone (GCTB) are infrequent tumors that usually impact the epiphyses of long bones and uncommonly manifest in the ribs. Herein, we report a case of asymptomatic GCTB directly invading the lung tissue. A 36-year-old man was referred to our emergency department with only left chest pain. Computed tomography revealed a large heterogeneous solid cystic mass in the left lung apex and amorphous calcification and distraction in the posterior part of the left fourth rib. Histological examination also exhibited that the GCTB originated from the rib. The patient underwent an en-bloc resection with no recurrence in his one-year follow-up. GCTB is characterized by osteoclast-like multinucleated giant cells and can exhibit aggressive local behavior. GCTB in the rib is rare, mainly found in the posterior arc. Radiographic features include lytic lesions with bone remodeling, often seen eccentrically in long bone epiphyses. Aggressive tumors may show cortical destruction and soft tissue extension. Surgery is often recommended for GCTB management, aiming for complete resection with sufficient surgical margins. The absence of well-defined diagnostic criteria hinders the accurate diagnosis of GCTB, making a comprehensive assessment through radiological and histological examinations crucial. Upon physical examination, GCTB should be considered in the differential diagnosis for mediastinal lesions, regardless of their size. Furthermore, surgical removal can be taken into account as the primary treatment strategy for tumors that originate from the posterior arc of the ribs, such as GCTB. •GCTB has rare occurrences in atypical sites like the ribs with aggressive behavior.•VATS can be useful in GCTB, providing surgical precision and ensuring tumor removal.•Long-term follow-up is essential for GCTB, given its tendency to recur.