Case 1 was a 74-year-old woman with a mass arising from tuberculous pleural callosity in her right lung. A biopsy specimen showed squamous cell carcinoma. She had radiation therapy and died 6 months after the onset of chest pain. Case 2 was an 84-year-old woman with a mass arising from tuberculous pleural callosity in her left lung. A biopsy specimen showed squamous cell carcinoma. She had radiation therapy and surgical resection of metastatic intestine tumors. She died 8 months after the diagnosis. Case 3 was an 81-year-old man with back pain. He had palliative surgery for metastatic lumbar spine, and the resected specimen showed squamous cell carcinoma. Chest computed tomography (CT) showed a mass arising from tuberculous pleural callosity in his left lung. They were all nonsmokers. It was believed important to consider the possibility of squamous cell carcinoma as a differential diagnosis of a mass arising from tuberculous pleural callosity.