Malignant mesothelioma in situ diagnosed by methylthioadenosine phosphorylase loss and homozygous deletion of CDKN2A: a case report.

Malignant pleural mesothelioma (MPM), associated with unfavorable outcomes, is closely associated with asbestos exposure. Early detection and treatment are critical to prolong survival of patients with MPM because of the rapid progression and resistance to treatment. The recently defined malignant mesothelioma in situ (MIS) has been gaining increasing attention with advances in genome-based methods including fluorescence in situ hybridization (FISH) as well as immunohistochemistry. We herein report the case of a MIS in a 73-year-old male with a history of asbestos exposure presenting with massive pleural effusion in the right thoracic cavity. Video-assisted thoracoscopic surgery with pleural biopsy of the right side revealed a single layer of atypical mesothelial cells without invasive lesions by hematoxylin and eosin staining. However, these mesothelial cells exhibited a loss of methylthioadenosine phosphorylase (MTAP) by immunohistochemistry and homozygous deletion of CDKN2A (p16) by FISH, leading to the diagnosis of MIS.

[Giant Cell Tumor of the Rib;Report of a Case].

We report a rare case of giant cell tumor of the rib. A 33-year-old man was admitted to our hospital because of a recently appearing mass and pain in the right chest wall. Chest computed tomography and magnetic resonance imaging revealed a heterogeneous mass of 8-cm in diameter arising from and destroying the right 7th rib. The tumor was resected together with the 6th, 7th, and 8th ribs and the adjacent muscle and diaphragm. The pathological diagnosis was giant cell tumor of the bone. The patient has been free from recurrence or metastasis for 4 years after the operation.

[Three cases of spontaneous pneumothorax by ruptured paravertebral gourd-shaped bullae].

We reported 3 elderly patients with right pneumothorax caused by ruptured paravertebral gourdshaped bullae. Two patients showed the characteristic symptom of air leakage of this type of pneumothorax, which decreased in the supine position, but increased in the sitting position. Chest computed tomography imaging showed bullae spreading in the space of the azygoesophageal recess. All patients underwent video-assisted thoracic surgery (VATS), and 2 patients underwent mini-thoracotomy because of adhesion and pyothorax. Ruptured bullae with stalks were found at the mediastinal sides of their right lower lobes in all patients. Bullectomy using an endoscopic stapler or ligation at the bulla root was performed easily and safely. The right pneumothorax caused by ruptured paravertebral gourd-shaped bulla was considered to be a good indication for the VATS due to the unique shape of the bulla, which has a stalk at its root.

[Surgery for benign schwannoma arising at the thoracic apex].

It is difficult to determine surgical approaches for treating a tumor arising at the thoracic outlet. Here we report a case of benign schwannoma arising at the thoracic apex, in which both pleural and cervical approaches were adopted. Chest radiographs of a 58-year-old male at the medical checkup in 2009 showed a tumor shadow in the right apical region that was increasing since 2003. He had no symptoms. Computed tomography(CT)and magnetic resonance imaging (MRI) showed a 35-mm tumor, which had a smooth surface and was suspected as a neurogenic tumor arising at the right thoracic outlet. Surgery for this tumor was performed by the thoracoscopic approach with a mini thoracotomy through the 3 intercostal space 1. The tumor was suspected to arise from the brachial plexus, and was not able to be enucleated. Then we made a cervical incision and the tumor was resected safely using a pleural approach together with a cervical approach. The pathological finding was benign shwannoma. Mild ulnar nerve palsy was observed in the patient after surgery, which gradually improved within 3 years.

Empyema necessitatis into the retroperitoneal space.

Empyema necessitatis is a rare complication of tuberculous empyema. We present a very rare case of empyema necessitatis into the retroperitoneal space through the diaphragm. The fistula between the thoracic empyema cavity and the retroperitoneal abscess was clearly identified by magnetic resonance imaging.