Yasushi Sakamaki

Alternative choices of total and partial thymectomy in video-assisted resection of noninvasive thymomas

BackgroundThe purpose of this report is to discuss the appropriate choice of procedures for video-assisted resection of thymoma according to factors such as the presence of myasthenia gravis or location of the tumor.MethodsWe evaluated the short-term results of thoracoscopic surgery for 30 consecutive cases of noninvasive thymoma. Unilateral thoracoscopic partial (or subtotal) thymectomy (UTPT) was employed in patients with nonmyasthenic thymoma localized to the unilateral mediastinum, and extended (or total) thymectomy by an infrasternal mediastinal approach (ETIS) in myasthenic cases or those in which total thymectomy was considered inevitable.ResultsUTPT was performed on 11 nonmyasthenic patients, and ETIS on 19 (13 myasthenics and six nonmyasthenics). Three patients in the ETIS group underwent conversion to sternotomy because of pericardial dissemination, pleural adhesion, and vascular injury, respectively. The mean surgical duration was 163 min and 224 min and mean blood loss was 123 g versus 149 g for UTPT and ETIS, respectively. Post-thymomectomy myasthenia occurred in a patient after UTPT who made an excellent recovery to remission after the re-UTPT. There has not been any recurrence detected for 48 months of mean postoperative follow-up.ConclusionsOur trial regarding the choice of total or partial thymectomy in thoracoscopic surgery for thymomas yielded acceptable results that warrant further investigations into long-term survival and recurrence after longer-term observation of patients undergoing these procedures.

Intermediate-term oncologic outcomes after video-assisted thoracoscopic thymectomy for early-stage thymoma.

OBJECTIVE To evaluate the impact on patient survival of video-assisted thoracoscopic surgery (VATS) thymectomy for the treatment of early-stage thymoma, by comparing the intermediate-term oncologic outcomes with outcomes after open thymectomy. METHODS Eighty-two patients who underwent complete resection of a Masaoka stage I or II thymoma between November 1998 and December 2011 were reviewed. RESULTS The patients included 32 men and 50 women (median age, 57 years; range, 20-90 years), of whom 44 had stage I thymoma and 38 had stage II thymoma. Seventy-one patients underwent VATS, of whom 4 (5.6%) underwent conversion to open thymectomy; the remaining 11 patients underwent planned open thymectomy. Thirty-six patients underwent total thymectomy and 46 underwent partial thymectomy. Operative mortality was nil. The tumor stage, tumor size, and proportion of patients who underwent total thymectomy were not significantly different between the open and VATS thymectomy groups. The median follow-up period was 49 months (VATS, 48 months; open, 52 months). There was a significant difference between the 2 groups for the estimated 5-year overall survival (VATS, 97.0%; open, 79.5%; P=.041) but not in the estimated 5-year recurrence-free survival. CONCLUSIONS Our findings indicate that the intermediate-term oncologic outcomes after VATS thymectomy for early-stage thymoma are as favorable as outcomes after open thymectomy. Further follow-up is still required to evaluate the long-term outcomes after VATS thymectomy.

Pheochromocytoma of the posterior mediastinum undiagnosed until the onset of intraoperative hypertension

An asymptomatic 42-year-old man was diagnosed with a posterior mediastinal mass, most likely a nonfunctioning, benign, neurogenic tumor for which thoracoscopic surgery was initially indicated. However, the systemic blood pressure rapidly increased to a critical level immediately after starting the surgical manipulation of the tumor, which was suggestive of a hyperfunctioning pheochromocytoma. The tumor was removed after controlling the blood pressure and was histologically diagnosed as a pheochromocytoma. The patient had an uneventful course, and the tumor was proven to be sporadic through further postoperative investigations. The possibility of extraadrenal pheochromocytoma should be considered in the preoperative diagnosis of an intrathoracic paraaortic tumor, even in an asymptomatic patient.

Non-small-cell lung cancer associated with non-thymomatous myasthenia gravis

A non-small-cell lung cancer without distant metastases was incidentally found in a 77-year-old man who had suffered from myasthenia gravis (MG) without thymoma. The patients condition was stabilized by oral pyridostigmine bromide which he had taken during the past 6 years. He simultaneously underwent thymectomy and left lower lobectomy with regional lymph node dissection. Although postoperative myasthenic crisis occurred, mechanical ventilation and intravenous steroid pulse relieved the patient and the symptoms improved thereafter. Cases of operable lung cancer with non-thymomatous MG have rarely been reported and the appropriate therapeutic strategy for such cases remains to be debated. Their causal association remains to be identified, whereas some studies have implied that immune disorder due to the abnormal thymus might possibly enhance the oncogenesis of extrathymic malignancies. Myasthenic crisis should also be taken into account in postoperative management of MG patients who simultaneously undergo thymectomy and lobectomy for synchronous lung cancer.

Mediastinal liposarcoma appearing as a tumor arising in the esophageal wall

We report a case of mediastinal liposarcoma, a relatively uncommon neoplasm, in which the mass also appeared as a tumor arising in the esophageal wall. A 76-year-old man diagnosed with a posterior mediastinal mass had the tumor extirpated in local esophageal myectomy due to its unclear margin on the esophageal wall. The resected specimen was diagnosed as well-differentiated liposarcoma. Preoperative angiography showed the tumor received its blood supply from a branch of the left gastric artery, suggesting it arose in the lower esophageal segment close to the hiatus and extended to the mediastinum. Since this tumors growth pattern differed completely from esophageal liposarcoma described in previous case reports, we concluded that it was mediastinal liposarcoma.

Pulmonary lymphoma of mucosa-associated lymphoid tissue type followed as a long-standing indeterminate lesion in immunoglobulin M-type paraproteinemia.

An 82-year-old woman with monoclonal immunoglobulin (Ig) M-type paraproteinemia had a large opacity in the right lung field. The abnormal shadow on roentgenogram had persisted for more than 6 years since the initial diagnosis of paraproteinemia, which had been diagnosed as Waldenströms macroglobulinemia (WM). Computed tomography revealed the lesion as a pulmonary tumor which was finally diagnosed as a marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) after surgical removal. MALT lymphoma constitutes the majority of primary pulmonary lymphomas and is often associated with monoclonal IgM-type paraproteinemia as well as WM, a distinctive lymphoproliferative disorder. Pulmonary MALT lymphoma should frequently be suspected in case of an indeterminate pulmonary tumor with IgM-type paraproteinemia.

A rare case of ectopic papillary thyroid carcinoma transformed into squamous cell carcinoma: Metastatic PTC transformed into SCC

A rare case of a metastatic ectopic papillary thyroid carcinoma (PTC) of the lung that transformed into a squamous cell carcinoma (SCC) that resembles pulmonary SCC is reported. A subcutaneous ectopic PTC in the left anterior neck area, together with a normal thyroid gland, were excised. The ectopic PTC showed thyroglobulin, TTF‐1 and PAX‐8 immunoreactivity and a BRAF V600E mutation. During the post‐operative follow‐up period, a rapidly growing 2 cm nodular lesion in the lower left lobe of the lung was detected. The lung tumor consisted of solid sheets and nests of squamous cells but without the nuclear features of PTC. Neither papillary nor follicular structures of cancer cells were identified. Carcinoma cells were positive for TTF‐1, PAX‐8, p40, CK14, and p63, while showing a high Ki‐67 labeling index and a BRAF V600E mutation. These results support our interpretation of a PTC that originated from ectopic thyroid tissue in the left anterior neck and that developed a lung metastasis showing squamous cell differentiation.