[Primary Spontaneous Pneumothorax with an Azygos Lobe].

A-21-year old man presented with dyspnea and a chest radiograph showed a right pneumothorax. Chest computed tomography revealed a collapsed lung and floating membrane, which was the lowermost part as a tear-shaped shadow. After the chest tube was inserted and surgical management was performed using a video-assisted thoracoscopic approach. At surgery, the visceral and parietal layers of pleura forming the mesoazygos were not fused, and azygos vein had a partial mobility. There was no adhesion between an upper lobe and visceral pleura. A stapling bullectomy was performed. The azygos lobe is a common malformation and has a reported incidence of 0.05~0.4% on health screening. The presence of an azygos lobe is usually assumed to be of no significance. We report a case and discuss the problems that it posed for surgical management.

[Bilateral Pneumothorax due to Pulmonary Metastasis from Angiosarcoma of the Forehead；Report of a Case].

Angiosarcoma is rare but highly malignant tumor arising from vascular endothelial cells. A 85-year-old man with difficulty in breathing for 3 days was referred to our hospital. He had a history of angiosarcoma of forehead 4 months before. A chest computed tomography (CT) scan showed left pneumothorax with multiple cystic changes and ground grass attenuations of bilateral lungs, which had obviously increased in recent 2 months. Pulmonary metastases with secondary pneumothorax was highly suspected by the serial CT findings. He was treated with tube thoracostomy and the instillation of a sclerosing agent (minocycline hydrochloride 200 mg). Seven weeks after his initial presentation, he died from obstructive pneumonia and an autopsy was held. Histologic examinations revealed that the tumor foci were peripheral, multiple and generally formed nodules. These cells were cluster differentiation (CD)31 and CD34 positive and negative for calretinin, cytokeratin, carcinoembryonic antigen (CEA), thyroid transcription factor (TTF-1) and epithelial membrane antigen (EMA). These findings were compatible with pulmonary metastases of angiosarcoma of forehead.

Circulating tumor cells (CTCs) in malignant pleural mesothelioma (MPM).

PURPOSE: To investigate the diagnostic and prognostic value of circulating tumor cells (CTCs), a potential surrogate of micrometastasis, in malignant pleural mesothelioma (MPM). METHODS: We prospectively evaluated CTCs in 7.5 mL of peripheral blood sampled from patients with a suspicion of MPM. A semiautomated system was used to capture CTCs with an antibody against the epithelial cell adhesion molecule. RESULTS: Of 136 eligible patients, 32 were finally diagnosed with nonmalignant diseases (NM), and 104 had MPM. CTCs were detected in 32.7 % (34 of 104) of MPM patients but in only 9.4 % (3 of 32) of NM patients (P = 0.011). The CTC count was significantly higher in MPM patients than in NM patients (P = 0.007), and a receiver operating characteristic (ROC) curve analysis showed an insufficient capability of the CTC test in discrimination between MPM and NM, with an area under ROC curve of 0.623 (95 % confidence interval, 0.523-0.723; P = 0.036). Among MPM patients, CTCs were more frequently detected in patients with epithelioid subtype (39.7 %, 31 of 78) than in those with nonepithelioid subtypes (11.5 %, 3 of 26; P = 0.016). Positive CTCs (CTC count ≥ 1) were a significant factor to predict a poor prognosis among epithelioid patients (median overall survival, 22.3 months for positive CTCs vs. 12.6 months for negative CTCs; P = 0.004) and not in nonepithelioid patients (P = 0.649). A multivariate analysis showed that positive CTCs were a significant and independent factor to predict a poor prognosis (hazard ratio, 2.904; 95 % confidence interval, 1.530-5.511; P = 0.001) for epithelioid MPM patients. CONCLUSIONS: CTC was a promising marker in diagnosis and prediction of prognosis in MPM, especially in epithelioid MPM.

Frequency of epidermal growth factor receptor mutations in Bangladeshi patients with adenocarcinoma of the lung.

BACKGROUND: Worldwide studies on lung adenocarcinoma have demonstrated a genetic divergence of the epidermal growth factor receptor (EGFR) pathway according to ethnicity, such as higher frequency of activated EGFR mutations among East Asian patients. However, such information is still lacking in some developing countries. METHODS: We investigated the frequency of EGFR mutations among Bangladeshi patients with adenocarcinoma of the lung. Fine-needle aspiration tissue samples were collected from 61 Bangladeshi patients. Polymerase chain reaction-single-strand conformation polymorphism was performed on extracted DNA for mutational analysis of EGFR exons 19 and 21. RESULTS: EGFR mutations were found in 14 of 61 (23.0 %) Bangladeshi patients. There was no significant difference in EGFR mutation rate with regard to patient's age, sex, smoking history, clinical stage of lung cancer, subtypes of adenocarcinoma, and tumor differentiation. CONCLUSION: The present study revealed that the EGFR mutation rate in Bangladeshi patients with adenocarcinoma of the lung was higher than in African-American, Arabian, and white Caucasian patients, and was lower than in East Asia.

Frequent inactivation of the BAP1 gene in epithelioid-type malignant mesothelioma.

In the present study, we analyzed genomic alterations of BRCA1-associated protein 1 (BAP1) in 23 malignant mesotheliomas (MMs), 16 epithelioid and seven non-epithelioid, consisting of 18 clinical specimens and five established cell lines. In examining these samples for homozygous deletions and sequence-level mutations, we found biallelic BAP1 gene alterations in 14 of 23 MMs (61%). Seven of these 14 MMs had homozygous deletions of the partial or entire BAP1 gene, another five had sequence-level mutations, including small deletions, a nonsense mutation, and missense mutations with additional monoallelic deletions, and the remaining two had homozygous mutations without allelic loss. All but one of the 14 BAP1 gene mutations were found in the epithelioid-type MMs; BAP1 mutations were found in 13 of 16 epithelioid-type MMs, but in only one of seven non-epithelioid-type MMs (13/16 vs 1/7; P = 0.005). There was no BAP1 mRNA expression in MMs with biallelic deletion and repressed expression was confirmed in MM specimens with deletion/mutation as compared with Met5a, SV40-transformed normal mesothelial cells. Western blot showed that seven of eight epithelioid MMs analyzed were BAP1 negative. Immunostaining with anti-BAP1 antibody in normal lung tissues revealed clear nuclear staining of normal mesothelial cells. No nuclear staining was observed among BAP1 mutation-positive MM tumors, whereas nuclear staining was observed among BAP1 mutation-negative MM tumors. These results suggest that the lack of the tumor suppressor BAP1 may be more specifically involved in the pathogenesis of epithelioid MM rather than non-epithelioid MM, and would be useful for diagnosis of epithelioid-type MM.

Circulating endothelial cell (CEC) as a diagnostic and prognostic marker in malignant pleural mesothelioma (MPM).

BACKGROUND: The purpose of this study was to investigate the diagnostic and prognostic value of circulating endothelial cell (CEC), a potential surrogate of tumor angiogenesis, in malignant pleural mesothelioma (MPM). METHODS: We prospectively evaluated CEC count in 4.0 mL of peripheral blood sampled from patients with a suspicion of MPM. An automated system was used to capture CECs with an anti-CD146 antibody. RESULTS: Of 109 eligible patients, 30 were finally diagnosed with non-malignant diseases, and 79 were with MPM. CEC count was significantly higher in MPM patients than in NM patients (mean CEC count, 120.3 and 39.9, respectively; P = 0.001), and a receiver operating characteristic (ROC) curve analysis showed that CEC provided a significant diagnostic performance in discrimination between MPM and nonmalignant diseases with an area under curve (AUC-ROC) of 0.700 (95 % confidence interval [95 % CI], 0.595-0.806; P = 0.001). Among MPM patients, CEC count was positively correlated with intratumoral microvessel density (MVD), a measurement of tumor angiogenesis (Spearman correlation coefficiency [r] = 0.444; P = 0.001). Higher CEC count (>50) was significantly associated with a poor prognosis (median overall survival, 11.4 months [95 % CI, 7.6-15.2] for higher CEC count patients versus 20.1 months [95 % CI, 16.0-24.2] for lower CEC count patients; P = 0.028). A multivariate analysis showed that higher CEC count was a significant and independent factor to predict a poor prognosis (hazard ratio [HR], 2.24, [95 % CI, 1.24-4.43]; P = 0.009). CONCLUSIONS: CEC, as a surrogate of tumor angiogenesis, was a promising marker in diagnosis and prediction of prognosis in MPM.

Practical approaches to diagnose and treat for T0 malignant pleural mesothelioma: a proposal for diagnostic total parietal pleurectomy.

Malignant pleural mesothelioma (MPM) remains suffering poor prognosis in spite of recent diagnostic and therapeutic progress. Although there is currently no established evidence, early diagnosis and early intervention may play a key role to improve prognosis of MPM, similarly to other malignancies. As pleural effusion is usually the first clinical sign of MPM, pleural effusion cytology is often the first diagnostic examination to be carried out. Since the sensitivity of pleural effusion cytology is approximately 60%, however, false-negative diagnosis is given to almost half of true MPM patients at this clinical step. One practical way to reduce the number of misdiagnosed MPM is to encourage performing thoracoscopic pleural biopsy unless definitive diagnosis other than MPM is established. There still remain a considerable number of patients with radiological/thoracoscopic T0 MPM who are misdiagnosed with nonspecific pleuritis after a complete investigation including thoracoscopic biopsies. Such patients will turn out to be malignant during follow-up period, although they have the best opportunity for long-term survival if only early therapeutic intervention is given. Currently, we are performing diagnostic total parietal pleurectomy in highly selected patients, who are characterized with strong clinical suspicion, positive pleural effusion cytology but uncertain pathological diagnosis, excellent cardiopulmonary reserve, and with written informed consent for highly invasive diagnostic surgery for pathologically unproven disease.

Treatment of bronchial fistula after extraplural pneumonectomy using flexible bronchoscopy with the administration of OK432, fibroblast growth factor basic and fibrin glue sealant.

Treatment options for bronchial fistula (BF) after pneumonectomy are often limited and carry significant morbidity and mortality. The patient underwent right extrapleural pneumonectomy for malignant pleural mesothelioma had BF without macroscopic fistula found by bronchography. We treated this minor BF using bronchoscopy with the administration of OK-432, fibroblast growth factor basic, and fibrin glue sealant. Two weeks after this treatment, we confirmed the improvement of the fistula by bronchography. Bronchoscopic therapy for BF was useful for a small, early fistula without infection.

Right Lower Lobectomy for an Aberrant Mediastinal Inferior Lobar Artery.

A 74-year-old woman was referred for a right lower lobe consolidation (maximum diameter, 73 mm) pathologically diagnosed as invasive mucinous adenocarcinoma (c-T4 N0 M0, c-stage IIIA). Computed tomography revealed an aberrant mediastinal inferior lobar branch (A6 and common basal artery [A7 to A10]) from the right main pulmonary artery (PA). Right lower lobectomy and lymph node dissection were performed. A mediastinal inferior lobar branch is extremely rare, and this patient with lung cancer underwent right lower lobectomy for all inferior PA branches (A6 and A7 to A10) arising from the main PA into the lower lobe.

Perivascular epithelioid cell tumor of the rib.

We present a rare case of perivascular epithelioid cell tumor (PEComa) in the right 6th rib of a 28-year-old man. A plain computed tomography scan showed a round osteolytic lesion in the right 6th rib. The resected tissue contained a globular-shaped, soft tumor. Histologically, the tumor was rich in vasculature and exclusively composed of perivascular epithelioid cells with clear cytoplasm. Immunohistochemically, the tumor expressed diffusely a melanocyte marker, human melanoma black-45, and focally a myogenic marker, alpha-smooth muscle actin, but not an epithelial marker, AE1/AE3. Fontana-Masson-positive melanin pigments were present and c-kit receptor tyrosine kinase (CD117), involved in the development of melanocytes but not myogenic cells, was expressed in tumor cells. These findings indicate that the tumor is PEComa with some differentiation into melanocytes. Notably, owing to the unique location of the occurrence, the tumor occupied bone marrow tissues of the rib, resulting that the tumor has the potential for hematogenous metastasis. In spite of the lack of cells with severe atypia, necrosis, and numerous mitoses, tumor cells invaded into surrounding tissues and overexpressed cyclin D1. To the best of our knowledge, this is the first case report of PEComa arising from the rib with the signs of malignant potential.

The clinical value of circulating tumour cells (CTCs) in patients undergoing pulmonary metastasectomy for metastatic colorectal cancer.

BACKGROUND: Circulating tumour cells (CTCs) are a potential surrogate for distant metastasis and are considered a useful clinical prognostic marker for metastatic colorectal cancer (mCRC). This prospective study evaluated the preoperative CTC count as a prognostic factor for pulmonary metastasectomy in mCRC patients. METHODS: Seventy-nine mCRC patients who underwent curative-intent pulmonary metastasectomy were included. Preoperatively, 7.5 mL of peripheral blood from each patient was quantitatively evaluated for CTCs with the CellSearch® system. The clinical significance of CTC count was evaluated according to Kaplan-Meier analyses and log-rank test. Multivariate analyses of the perioperative variables were performed. RESULTS: The distribution of CTC counts were as follows; 0 in 66 patients (83.5%), 1 in eight patients (10.1%), 2 in three patients (3.8%), and 3 and 6 in one patient (1.3%). The patients with multiple CTCs (CTC count ≥2) had significant shorter disease-free survival (DFS) (P=0.005, median DFS; 19.8 vs. 8.6 months) and overall survival (OS) (P=0.035, median DFS; not reached vs. 37.8 months), respectively. Multivariate analysis showed the patients with multiple CTCs had elevated risk of recurrence [hazard ratio (HR), 3.28; 95% confidence interval (CI), 1.24-8.67; P=0.017]. CONCLUSIONS: The detected rate of CTCs was quite low in mCRC patients who underwent pulmonary metastasectomy. The patient with multiple CTCs had shorter DFS in this study. The larger prospective clinical study is needed to establish the meaning of CTC in mCRC candidate for pulmonary metastasectomy.

Positive correlation between postoperative tumor recurrence and changes in circulating tumor cell counts in pulmonary venous blood (pvCTC) during surgical manipulation in non-small cell lung cancer.

BACKGROUND: In non-small cell lung cancer (NSCLC), circulating tumor cells (CTC) are shed and circulate to the peripheral blood through the pulmonary vein. Previously, CTC count in pulmonary venous blood (pvCTC) was shown to significantly increase after surgical manipulation. Therefore, we assessed the correlation between the changes in the pvCTC count (ΔpvCTC) and clinical outcomes. METHODS: Consecutive patients with peripheral-type, NSCLC, who underwent lobectomy or bi-lobectomy through open thoracotomy, were enrolled prospectively. Before and after lobectomy, 2.5 mL of blood was drawn from the associated lobar pulmonary vein (PV), and was served for the quantitative evaluation of CTC using the CellSearch® system. The cut-off point of ΔpvCTC was determined according to clinical outcomes and ΔpvCTC using receiver operation characteristic (ROC) curve. Then the correlation between ΔpvCTC and clinical outcomes was evaluated by Kaplan-Meier analyses and log-rank test. In addition, the correlation between ΔpvCTC and perioperative variables was assessed. RESULTS: A total of 30 patients were enrolled, tumor recurrence occurred in 11 patients over a median follow-up of 64.4 months. Of these, 7 patients had distant metastasis and 4 had local recurrence. The median ΔpvCTC was 49 cells/2.5 mL, and pvCTC-count was increased during surgical manipulation in 24 patients (80%). We divided patients into two groups based on ΔpvCTC with the cut-off value as 119 cells/2.5 mL according to ROC curve. Significant shorter time to distant metastasis (TDM) (P=0.0123) was observed in high ΔpvCTC group (ΔpvCTC ≥119 cells/2.5 mL) than low ΔpvCTC group (ΔpvCTC <119 cells/ 2.5mL). Neither disease-free survival (DFS) nor overall survival (OS) was significantly correlated with ΔpvCTC. CONCLUSIONS: Increasing pvCTC count during surgical manipulation was significantly correlated with postoperative distant metastasis in completely resected NSCLC patients. Significant shorter TDM was observed in patient with high ΔpvCTC group.

Circulating Tumor Cell Count Can Be a Useful Prognostic Factor in Lung Resection via Cardiopulmonary Bypass.

Tumor resection with cardiopulmonary bypass (CPB) remains controversial in the field of oncology. Here, we present a 57-year-old male patient with locally advanced squamous cell carcinoma. The tumor was located in the left hilum and invaded the left atrium. Complete resection, left pneumonectomy combined with partial left atrium resection, was achieved using CPB. We evaluated the circulating tumor cell (CTC) counts, as a surrogate for micrometastasis, in peripheral blood and the CPB circuit. Both CTC counts were 0, which could indicate local disease without micrometastasis. CTC count may be a useful indicator for tumor resection with CPB in lung cancer.

Long-term pulmonary function after lobectomy for primary lung cancer.

The aim of this study was to investigate the factors affecting long-term postoperative pulmonary function with a view to increasing the application of combined resection, bronchoplasty, and induction therapy. Results in 80 patients who underwent lobectomy for primary lung cancer were analyzed. Predicted postoperative pulmonary function was calculated using the formula: postoperative predicted function=preoperative function x[1-(b-n)/(42-n)], where n and b are the numbers of obstructed segments and total segments, respectively, in the resected lobe. Spirometry was performed serially on the preoperative day, and at 3, 6, 12, 18, and 24 months postoperatively. The difference between the predicted postoperative pulmonary function and the function measured at 12 months postoperatively was calculated, and clinical and therapeutic variables were analyzed. Univariate analysis revealed that the difference in vital capacity was significantly related to surgical approach, bronchoplasty, and induction therapy, while the difference in forced expiratory volume in one second (FEV1) correlated with surgical approach and induction therapy. Multiple regression analysis showed induction therapy to be the sole factor related to the differences in both vital capacity and FEV1. Lung resection after induction therapy may cause an additional loss of pulmonary function in the late phase.

Pleural vasculitides of microscopic polyangiitis with asbestos-related plaques.

A 69-year-old man who had been exposed to asbestos for approximately 40 years presented with the complaint of fever and pleuritic chest pain on the right side on deep inspiration. Chest X-ray films showed pleural effusion in the right side. Initial antibiotic treatment was ineffective. The hyaluronic acid level was high in the pleural effusion but no malignant mesotheliomal cells were seen with blind pleural biopsy. Blood chemistry showed a remarkable high titer of myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) and open renal biopsy suggested crescentic glomerulonephritis. The precise pathological examination on the pleura obtained by the open pleural biopsy showed vasculitides and plaque leading to diagnosis of microscopic polyangiitis (MPA). This is a rare case of MPA seen in the pleural arteries.

Immunohistochemical analysis of resected clinical stage I pulmonary adenocarcinomas with high preoperative levels of serum carcinoembryonic antigen.

BACKGROUND: Clinical stage I pulmonary adenocarcinoma (AD) patients with persistently high serum carcinoembryonic antigen (CEA) levels after surgery have a poor prognosis. Although CEA staining pattern is reported to be a prognostic indicator for patients with colorectal cancer, the relationship with lung cancer is unclear. METHODS: One hundred eighteen patients with clinical stage I AD underwent surgery from 1993 to 1997. Of them, 19 (16%) patients with a high preoperative serum level of CEA and 19 randomly selected control patients with preoperatively normal CEA were studied. CEA staining of tumor specimens from each of the 38 patients was performed, and the staining patterns were then classified into two types: apical and diffuse. RESULTS: Patients with normal postoperative serum CEA levels (group HN, n = 13) had a 5-year survival rate higher than those with persistently high postoperative serum CEA (group HH, n = 6). In a comparison between the two groups, apical patterns (n = 10) were only seen in group HN, and those who demonstrated an apical CEA staining pattern had a 5-year survival rate (5-YSR) of 80% as compared with 13% for those HN patients with only a diffuse pattern (p = 0.01). In the control group, 16 (84%) patients had an apical staining pattern and the other 3 patients showed no staining. CONCLUSIONS: Patients with normalized serum CEA levels had a high chance of showing an apical staining pattern, which may be a very good prognosis predictor for patients with high preoperative levels of CEA.

Serum carcinoembryonic antigen level in surgically resected clinical stage I patients with non-small cell lung cancer.

BACKGROUND: There is little general agreement concerning the effectiveness of serum carcinoembryonic antigen (CEA) as a prognostic indicator for non-small cell lung cancer (NSCLC) in clinical stage I patients. We conducted a retrospective study to investigate the relationship between serum CEA level and survival. METHODS: We assessed 297 consecutive patients with clinical stage I NSCLC who underwent surgical resection at Toneyama National Hospital from 1985 to 1998. Serum CEA levels were measured with an enzyme-linked immunosorbent assay kit with the upper limit of normal defined as 7.0 ng/mL based on the 95% specificity level for benign lung disease, in our hospital. RESULTS: There were 56 (19%) patients with serum CEA greater than 7.0 ng/mL. The high CEA group had a median survival time of 50 months and a 5-year survival rate of 49% compared with a 5-year survival rate of 72% (p < 0.0001) for the normal CEA group (n = 241). Patients with postoperatively high CEA levels (n = 15) had the worse prognosis (median survival time 35 months, and 5-year survival 18%) compared with patients whose levels returned to normal (n = 41, median survival time 8.8 months, and 5-year survival 68%; p = 0.01). These differences were also observed in patients with pathologic stage I or II tumors but not in those with pathologic stage III or IV tumors. CONCLUSIONS: Serum CEA level is a useful predictor of survival for patients with clinical stage I NSCLC, and a persistently high CEA level after surgery is an especially strong indicator of a very poor prognosis.

Thymic carcinoma with a large cystic lesion.

A 59-year-old man presented with a large anterior mediastinal mass. A computed tomography (CT) and magnetic resonance imaging showed a well-circumscribed cystic mass, 12 cm in size adjacent to the heart border and superior vena cava (SVC). A CT guided needle biopsy was performed, and instead of detecting malignant tissues but finding that gray muddy fluid was suctioned, suggesting cystic teratoma. At surgery, the tumor was confirmed advanced thymic carcinoma with pleural dissemination, then the tumor was extirpated with resection of SVC, followed by 2 cycles of chemotherapy. Histologically, the cystic wall was lined with malignant cells. We herein present a diagnostic pitfall case of thymic carcinoma having a large cystic component with which rare association should be recognized.

Prognostic significance of persistent mediastinal metastasis following induction therapy in large (> or = 2 cm) N2 or N3 non-small cell lung cancer.

OBJECTIVE: It is controversial whether or not surgery is beneficial for patients with non-small cell lung cancer accompanied by persistent lymph node metastasis in the mediastinum following induction therapy. We have therefore conducted a retrospective study to assess this issue. METHODS: Eligibility criteria were defined as follows: 1) the period of treatment was between January 1991 and April 1998, 2) the clinical stages were IIIA (N2) or IIB (N3) with large lymph nodes (> or = 2 cm), 3) induction therapy had been administered, 4) tumor was resected completely, 5) at least one mediastinal lymph node had necrosis or scar if the pathological N status was p-N0 or p-N1 and 6) the p-stage was not IV. Dichotomous variables included the radiographic response of the tumor, the T status, and the N status. RESULTS: Thirty-nine patients were eligible. There were 29 males and 10 females aged from 27 to 74 years, and involved 20 cases of adenocarcinoma. The pathological N status was as follows: p-N0 in 18 patients, p-N1 in 3, p-N2 in 16, and p-N3 in the other 2. In overall survival, the median survival time (MST) was 34 months and the actuarial 5-year-survival rate (5-YSR) was 28%. The group of patients with either N0 or N1 (n = 21) had a 71-month MST and a 54% 5-YSR, and the group of patients with either N2 or N3 (n = 18) had a 13-month MST and a 5-YSR of 0% (p < 0.0001). On multivariate analysis, the pathological N factor was confirmed as an independently significant. CONCLUSIONS: Our retrospective study found that the survival rate of patients with persistent mediastinal nodal metastasis was very poor. A prospective study is needed to investigate whether or not surgery is beneficial for these patients.

Significant increase in circulating tumour cells in pulmonary venous blood during surgical manipulation in patients with primary lung cancer.

OBJECTIVES: Circulating tumour cells (CTCs) are tumour cells shed from a primary tumour and circulate in the peripheral blood after passing through the drainage vein. In previous studies, we showed that high numbers of CTCs were detected in the drainage pulmonary venous blood of most patients with resectable primary lung cancer, whereas only low numbers of CTCs were detected in the peripheral blood of some patients. Accordingly, this prospective study was conducted to assess changes in CTCs in the drainage pulmonary vein (PV) during lung cancer surgery. METHODS: A total of 30 consecutive peripheral-type primary lung cancer patients who underwent lobectomy (or right upper and middle bilobectomy) through open thoracotomy were included. For each patient, 2.5 ml of blood was sampled from the lobar PV of the primary tumour site before and after surgical manipulation for lobectomy. The CTCs were evaluated quantitatively with the CellSearch® system. RESULTS: Before surgical manipulation, CTCs were detected in PV blood in the majority of patients (22 of 30, 73.3%), although CTCs were detected in peripheral blood in only two patients (6.7%). The median number of CTCs in the PV (pvCTC-count) before surgical manipulation was 4.0 cells/2.5 ml, and there was no significant correlation between pvPV-count and any clinicopathological characteristic, including tumour size, progression and histological type. After surgical manipulation, at the time of completion of the lobectomy, the pvCTC-count significantly increased (median, 60.0 cells/2.5 ml; P = 0.001). The increase in pvCTC-count was significantly associated with microscopic lymphatic tumour invasion (ly); pvCTC-count significantly increased in ly-positive patients (pvCTC-count before and after surgical manipulation, 4.0 and 90.5 cells/2.5 ml, respectively; P = 0.006), but not in ly-negative patients (3.5 and 7.0 cells/2.5 ml, respectively; P = 0.153). The increase in pvCTC-count was not significantly associated with any other clinicopathological factor or with any surgical procedure, including the sequence of vessel interruption. CONCLUSIONS: We documented a significant increase in CTC count in drainage PV blood after surgical manipulation, especially in tumours with lymphatic invasion. We are awaiting survival data at 5 year follow-up examination, which may provide clinical significance of the pvCTC-count.