Kiyofumi Mitsui

Preoperative radiotherapy and surgery for advanced thymoma with invasion to the great vessels

From 1983 to 1994, 12 advanced thymomas with invastion to the great vessels were initially treated by irradiation (mean dose, 18.3 Gy) and subsequent surgical resection. In nine patients, complete resection was possible by concomitant resection of the surrounding tissues, mainly pericardium and/or brachiocephalic vein. Histologically, all tumors showed prominent fibrosis. Ten patients also received postoperative radiotherapy (mean dose, 42.3 Gy). Tumor‐related deaths occurred in only two patients; one who did not receive postoperative irradiation 21 months and one who had viable cells at the surgical margin 10 months after operation. However, there were also 2 patients who died of respiratory failure due to operation and/or irradiation, one 45 days and the other 7 years after the treatment. Preoperative radiotherapy could facilitate complete resection of the advanced thymomas. The prognosis of the patients treated with preoperative radiotherapy seemed fair if followed by adequate resection and subsequent irradiation.

The Role of Preoperative Radiotherapy for Invasive Thymoma

Six patients with large invasive thymomas were treated by preoperative irradiation with 12 to 20 Gy before total or partial resection of the tumor. The responses of these 6 thymomas were estimated on the chest radiograms as follows; complete response in 2 patients, partial response in 3 and no response in one. Although the clinical responses varied, the surgical specimens of all the tumors pronounced severe fibrosis, probably not related to irradiation, and necrotic foci with a few viable tumor cells. Total resection of the thymoma was performed in 3 patients and subtotal resection in 3. Adhered or involved surrounding tissues such as the pericardium, pleura and/or veins were also resected in most patients. Preoperative radiotherapy facilitated total or subtotal resection of the invasive thymoma mass by reducing the tumor volume.

Clear cell carcinoma of the lung: a case report and review of the literature

Clear cell carcinoma of the lung is an extremely rare type of lung cancer with doubtful etiology. This present case showed that the tumor cells contained abundant cytoplasmic glycogen with a diffusely distributed pattern and intracellular glandular structure electron microscopically. Immunohistochemical study revealed that the tumor cells expressed not only epithelial marker including cytokeratin and epithelial membrane antigen, but also Ley, one of stage-specific embryonic carbohydrate antigens. The diagnosis of pulmonary clear cell carcinoma should be done carefully, because benign clear cell tumor and secondary renal cell carcinoma show similarities in a histologic appearance but not in their management and prognosis.

Radioresponse of thymomas verified with histologic response

Patterns of radiologic response of 10 thymomas treated by preoperative radiotherapy (RT) (18-20 Gy/2 weeks) were determined in conjunction with histologic response. Changes in tumor volume were evaluated with CT scans obtained 5 to 36 days before and 14 to 24 days after the initiation of RT and before surgery. The extent of tumor volume reduction (TR) varied widely (40-78%), while the mean daily volume decrement expressed as a percentage of the pre-RT tumor volume correlated significantly with the pre-RT tumor volume. Histologically, the tumors, all of which were resected 17 to 33 days after RT initiation, generally consisted of predominant fibrous tissues, rare necrotic foci, and few epithelial cells. The TR did not correlate with pre-RT tumor volume, observation period, histologic subtype, or quantity of remaining epithelial cells. The TR of thymomas does not predict RT impact on tumor cells but does reflect the quantity of inherent tumor stroma.

Encapsulated Type II Pneumocyte Adenoma: A Case Report and Review of the Literature

An unusual benign lung neoplasm, a papillary adenoma of type II pneumocytes, was resected from a 26-year-old man who showed no clinical symptoms. The tumor was 2.0 cm in diameter and was localized in the subpleural region of S7 of the right lung; the cut surface showed a spherical medullary mass encapsulated by a thin layer of connective tissue. Histologically, there were cuboidal to columnar epithelial cells with a little nuclear atypia showing a monotonous papillary pattern with a delicate stroma in most parts of the tumor. There was neither capsular invasion nor metastasis of tumor cells. Nuclear DNA analysis of the tumor cells showed a diploid pattern and a low S-phase fraction. The immunohistochemical study revealed that most tumor cells contained a large amount of surfactant apoprotein in the cytoplasm. Osmiophilic lamellar bodies characteristic of type II pneumocytes were frequently found by electron microscopy. These findings indicate that this was a benign adenoma of the lung arising from type II pneumocytes.

Successful reconstruction for combined tracheal and bronchial disruption

After a head-on automobile collision, a 21-year-old man was admitted with respiratory distress and subcutaneous emphysema. Bronchoscopy revealed a disruption of the trachea and a complete transection of the intermediate bronchus. A right posterolateral thoracotomy was performed, and both lesions were reconstructed primarily using absorbable materials.

Comparative DNA Analysis by Image Cytometry and Flow Cytometry in Non-small Cell Lung Cancer

To determine whether image cytometry (ICM) is advantageous for clinical DNA analyses of tumor cells, nuclear DNA contents measured by ICM were compared with those by flow cytometry (FCM), using 46 samples of non‐small cell lung cancers. ICM was performed on smear specimens of fresh materials (f‐ICM) and cell suspensions obtained from paraffin‐embedded tumors (p‐ICM). The same cell suspensions were also analyzed by FCM (p‐FCM). Aneuploid rates/coefficient of variation (CV) of f‐ICM, p‐ICM, and p‐FCM were 76.1/4.90, 71.7/5.01 and 60.9/5.31%, respectively. There was a high correlation in the DNA indices between p‐ICM and p‐FCM (r=0.80). In the comparative DNA analysis, there were seven discordant samples. Six of them were estimated as aneuploid by p‐ICM, but they were miscounted as diploid or undefinablc (impossible) by p‐FCM. This was caused by measuring condensed nuclei or debris. All “impossible” samples in p‐FCM were squamous cell carcinoma with necrosis. In cell cycle analysis, the S and S+G2/M phase fractions in diploid samples were higher in p‐ICM than those in p‐FCM (P< 0.005), because the GO/G1 phase (2N) fraction presented by FCM was composed of cancer and non‐malignant cells in diploid cancers. In ICM, they can be separately measured by means of morphological selection. These findings indicated that ICM is superior to FCM, especially for the practical DNA measurement of a few cancer cells and in the evaluation of the proliferation rates.

Transtracheal endoluminal resection of a pleomorphic adenoma occluding subglottis.

A 71-year-old male was treated for suspected bronchial asthma because of dyspnea and stridor for 3 months before presenting at our hospital. Chest computed tomogram and a laryngotracheoscopy revealed a mass occupying the subglottic cavity. Instead of a laryngotracheal resection, the tumor was extirpated from the posterior wall of the subglottis and the first two tracheal rings successfully through a vertical tracheotomy just above the life-saving trachestomy tube, and was diagnosed as pleomorphic adenoma. The patient is alive and well with no recurrent tumor 12 years after surgery, without any effect on the function of the voice or swallowing.

Suppression of Prostanoid Formation and Regulation of Peripheral Circulation After Surgery Using Thrombin Inhibitor (MD805)

We studied the effects of thrombin generation due to surgical stress on prostanoid formation and peripheral circulation in anesthetized dogs. Three experimental groups were used, consisting of a control group (group 1), a thoracotomized group (group 2), and a thoracotomized group treated with thrombin inhibitor (MD805: a synthetic arginine derivative) (group 3). The plasma concentrations of thrombin-antithrombin III complex (TAT) and prostanoids were measured along with the hemodynamic parameters. The plasma concentrations of TAT and thromboxane B2 significantly increased 1h after a thoracotomy in group 2. However, neither concentration increased after a thoracotomy in group 3. The flow ratio of the brachial and femoral arteries to cardiac output significantly decreased 1h after a thoracotomy in group 2. This study indicates that thromboxane A2 was thus synthesized by the stimulation of endogenous thrombin, while it also reduced the peripheral blood flow after surgery.

The Relationship between Histocytological Features of Superficial Layer of Tumor and the Tumor Extent of Early Squamous Cell Carcinoma of the Bronchus.

早期肺扁平上皮癌組織表層の角化の程度と, 表層細胞の核形態および腫瘍進展度との関係を検討した. 対象は切除した早期肺扁平上皮癌32例の33病巣で, これらを腫瘍表層の角化の程度によって, 明らかな角化のない軽度角化7病巣, 角化は明らかだが最表層の数層に留まる中等度角化8病巣, 角化の著明な高度角化18病巣に分類した. 角化の明らかな中等度ないし高度角化8病巣が, 異型の少ない小型核を持つ角化細胞で覆われていた. これらは細胞診にて見逃され易いものである. 高度角化18病巣中, 中心型が14病巣, 気管支軟骨外進展が7病巣で, いずれも3型中最も多かった. 一方, 軽度角化7病巣では, 表層進展型が5病巣, 20mm以上の大きさの病巣が4病巣と多数を占めた. 従って, 高度角化病巣には中心型で深達進展高度なものが多く, 軽度角化病巣には表層進展型で比較的広がりの大きいものの多いことが知られた.