Post-coronavirus disease 2019 organizing pneumonia confirmed pathologically by video-assisted thoracoscopic surgery.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has become a global pandemic. Many survivors of serious COVID-19 pneumonia have long-term residual pulmonary disease. However, there is little documentation of the histopathological characteristics of lung sequelae post-COVID-19 and effective treatments. We present two Japanese cases of lung sequelae post-COVID-19. The patients were histopathologically diagnosed with organizing pneumonia (OP) or OP with fibrosis and no diffuse alveolar damage on video-assisted thoracoscopic surgery. Case 1, who had been diagnosed with OP, was successfully treated with corticosteroid and other immunosuppressive agents over a 6-month period. Although case 2, who had been diagnosed with OP with fibrosis, had a partial and unsatisfactory response to immunosuppressive agents, the patient responded to antifibrotic treatment including nintedanib.

Descending necrotizing mediastinitis associated with Lactobacillus plantarum.

BACKGROUND: Descending necrotizing mediastinitis (DNM), a severe infection with a high fatality rate, develops in mediastinal spaces due mainly to deep cervical abscesses. The majority of causative microbes of DNM are Streptococci and oral anaerobes. DNM associated with Lactobacillus-infection is rather rare. CASE PRESENTATION: A 69-year-old male with an unremarkable past medical history was referred to our hospital for surgical resection of advanced laryngeal cancer. Full examination revealed a neck abscess and DNM with a background of untreated diabetes mellitus. Initially, he was treated with meropenem. However, Lactobacillus plantarum was isolated from surgical drainage of a mediastinal abscess. Despite using antibiotics capable of eradicating all isolates with susceptibilities not differing significantly from those of the neck and mediastinal abscesses, we attributed DNM to the L. plantarum detected only in the mediastinal abscess. After DNM treatment, he underwent total pharyngolaryngectomy with bilateral neck dissection followed by reconstruction using free jejunum. He was discharged fully recovered. CONCLUSION: We concluded that L. plantarum as the sole cause of the mediastinal abscess in the present case cannot be ruled out. As the number of immunocompromised patients increases, we should be cautious regarding this "familiar" microbe.

Thoracoscopic surgery for non-small-cell lung cancer: elderly vs. octogenarians.

BACKGROUND: Octogenarians are rarely referred for surgical treatment of lung cancer owing to the morbidity and mortality of pulmonary resection, their frailty, and limited lifespan. We reviewed the results of thoracoscopic surgery, performed completely under the monitor, for treatment of primary non-small-cell lung cancer in octogenarians, and compared them with those in elderly patients. PATIENTS AND METHODS: Between September 25, 2002 and August 25, 2011, a retrospective database of 24 octogenarians and 70 elderly patients (age range, 75-79 years) who underwent thoracoscopic surgery for treatment of primary non-small-cell lung cancer were reviewed. Demographic, histopathologic, preoperative, perioperative, postoperative, outcome variables, and survival were assessed. RESULTS: In the octogenarian group, 29% had postoperative respiratory complications, 4% had postoperative cardiac complications, operative mortality was 4%, the recurrence rate was 8%, and the postsurgical 5-year survival rate was 74%. In the elderly group, 25% had postoperative respiratory complications, 6% had postoperative cardiac complications, operative mortality was 3%, the recurrence rate was 6%, and the postsurgical 5-year survival rate was 80%. CONCLUSIONS: Thoracoscopic surgery for treatment of primary non-small-cell lung cancer can be performed with similar postoperative complication rates, operative mortality, and survival in octogenarians when compared to elderly patients.

Complete video-assisted thoracoscopic surgery for lung cancer in 400 patients.

BACKGROUND: We report the results of complete video-assisted thoracoscopic surgery for treatment of primary non-small cell lung cancer, which was performed completely through the monitor in 400 consecutive patients. PATIENTS AND METHODS: Between September 25, 2002 and August 25, 2011, a retrospective database of 400 consecutive patients who underwent complete video-assisted thoracoscopic surgery for treatment of primary non-small cell lung cancer was reviewed. Demographic, histopathologic, preoperative, perioperative, postoperative, and outcome variables were assessed using standard descriptive statistics and Kaplan-Meier survival analyses. RESULTS: Operating time was 258.13 ± 62.53 min, volume of blood loss was 253.21 ± 206.66 mL, duration of drainage was 3.6 ± 3.2 days, volume of drainage was 708.1 ± 522.8 mL, the postoperative respiratory complication rate was 14.8%, the reoperation rate was 1.3%, and operative mortality was 1.0%. The 5-year postsurgical survival rates for pathologic stages I, II, and III were 93.9%, 62.0%, and 61.6%, respectively; the 3-year postsurgical survival rate for pathologic stage IV was 40.0% CONCLUSIONS: Complete video-assisted thoracoscopic surgery for treatment of primary non-small cell lung cancer is associated with safety and acceptable postoperative complication rates, operative mortality rates, and survival rates.

Staple line coverage with a polyglycolic acid sheet plus pleural abrasion by thoracoscopic surgery for primary spontaneous pneumothorax in young patients.

PURPOSE: We investigated surgical results of staple line coverage with a polyglycolic acid sheet plus pleural abrasion by thoracoscopic surgery for treating primary spontaneous pneumothorax in young patients. METHODS: Forty-seven patients younger than 40 years underwent 48 thoracoscopic surgical procedures for spontaneous pneumothorax at the Division of Thoracic Surgery, Department of Surgery, Nippon Medical School, from May 2007 through August 2010. All patients underwent thoracoscopic bullectomy with stapling devices and pleural abrasion performed with a gauze sponge held by forceps until the pleura became petechial. Finally, the staple line was covered with a polyglycolic acid sheet (10 × 10 cm). No fibrin glue was used. We investigated both short-time results after surgery and the postoperative recurrence of pneumothorax. RESULTS: There was no operative mortality or morbidity, such as air leakage from staple lines or hemorrhage due to pleural abrasion. Pneumothorax recurred after surgery in 3 cases. In 2 cases, neither re-operation nor tube thoracostomy was necessary because intrapleural adhesions allowed only partial collapse of the lung. One patient underwent re-operation for an overlooked bulla facing the diaphragm in left lower lobe of the lung 2 days after the first operation. The rate of freedom from pneumothorax 4 years after surgery was 94%. CONCLUSIONS: Staple line coverage with a polyglycolic acid sheet plus pleural abrasion by thoracoscopic surgery is a useful method for preventing morbidity and the postoperative recurrence of pneumothorax.

Clinicopathological characteristics and prognosis of non-small cell lung cancer patients associated with a family history of lung cancer.

INTRODUCTION: Clinicopathological characteristics and prognosis of non-small cell lung cancer (NSCLC) patients with a family history of lung cancer (FHLC) have not been well established. METHODS: Clinical records of patients with NSCLC treated at our institute from 1982 to 2010 were reviewed with special reference to family history of lung cancer and clinicopathological factors including patient's outcome. Univariate analyses of the factors between the groups of FHLC and non-FHLC were performed using unpaired two-tailed t tests or the chi-square test. The Cox proportional hazards model was used to evaluate the hazard ratio of death. RESULTS: Of the 1013 NSCLC patients, 124 (12.2%) had a FHLC of whom 119 (96%) were the first-degree relatives. The frequency of early stages of lung cancer was high in both groups of FHLC and non-FHLC patients. Patients with FHLC had a significantly higher frequency of early pathological stages and a prepomderance of adenocarcinoma, and a hazard ratio of death of 0.870 (95% confidence interval: 0.599-1.263, p value: 0.465) compared with the non-FHLC patients. CONCLUSIONS: NSCLC patients with FHLC could be characterized by early pathological stages and preponderance of adenocarcinoma, however they were not at a decreased hazard ratio of death. These findings emphasize the importance of early detection of lung cancer and employment of less invasive therapeutic interventions.

Unification of T2a and T2b tumors to T2 tumors in non-small cell lung cancer staging.

INTRODUCTION: We investigated the validation of the seventh edition of the TNM staging (2009) system for lung cancer, retrospectively. METHODS: From January 1990 to March 2004, 1629 patients who underwent lung resection with systemic lymph node dissection for non-small cell lung cancer at Nippon Medical School and Saitama Cancer Center were included. The overall survivals after surgery by each pathological stage according to the 1997 and 2009 systems were statistically analyzed using Kaplan-Meier estimated survival curves, and the significance of the difference was analyzed by the log-rank test. RESULTS: The 2009 system had significant prognostic distinction between each T descriptor except for T2a and T2b, and between each M descriptor. The 2009 system had better prognostic distinction between each pathological stage except for stages IB and IIA, and stages IIIB and IV. In the simulation, we unified T2a and T2b tumors into T2 tumors, and T2bN0M0 and T2bN1M0 were moved to stages IB and IIA, respectively. This proposed system had significant prognostic distinction between the proposed IB, IIA, and IIB stages. CONCLUSIONS: The 2009 system provides better patient selection for surgery and prognostic distinction between each stage except for stages IB and IIA, and stages IIIB and IV, compared with the 1997 system. Unification of T2a and T2b tumors to T2 tumors can improve prognostic distinction between stages IB and IIA.

Surgical results of completion pneumonectomy.

PURPOSE: We report our experience with completion pneumonectomy (CP). METHODS: We report on operative procedure and morbidity, mortality, and survival rates. RESULTS: CP was performed for malignancy in 12 patients and postoperative complications after the first operation in 4 patients. Intrapericardial dissection of vessels was performed in 14 patients (87.5%). Partial vertebrectomy from the second to the fifth vertebrae was performed in 1 patient. Carinal resection was performed in 2 patients. Morbidity including bronchopleural fistula, pulmonary insufficiency, pyothorax, and pulmonary infarction developed in 6 of the 16 patients (37.5%). Mortality rate was 18.8%. The actuarial 1-, 3-, and 5-year overall survival after CP for all malignancy was 80.8%, 49.0%, and 49.0% respectively. CONCLUSIONS: The morbidity and mortality rates are high in CP. Combined resection, especially carinal resection, appears to be contraindicated in CP. CP is one of the treatments of choice, even for malignancy, if complete resection is possible because of the good long-term survival.

Surgical treatment of metachronous nonsmall cell lung cancer.

PURPOSE: We report surgical results of metachronous nonsmall cell lung cancer (NSCLC). METHODS: We report mortality and analyze prognostic factors for overall survival in patients with metachronous NSCLC at Nippon Medical School from July 1982 to July 2008. RESULTS: Thirty-three out of 1726 patients (1.9%) who underwent lung resection had metachronous NSCLC. Mortality rate was 10%. On univariate analyses, the different histologies at the first and second operations were the only significant poor prognostic factor. Twenty-two patients (73%) had the same histology at the first and second operations: adenocarcinoma in 18 (60%) and squamous cell carcinoma in 4 (13%). Their actuarial 5- and 10-year overall survivals were both 71%, compared to 47% and 16% for patients with different histology (p = 0.0174). Sex (p = 0.1742), locations of the first and second cancers (p = 0.3957), operative procedures in patients with p-stage I at the second operation (p = 0.2782), pathological stage at the first operation (p = 0.5958), and pathological stage at the second operation (p = 0.0609) were not prognostic factors. Different histology at the first and second operations was significant based on a multivariate analysis (Hazard ratio: 3.918; p value: 0.0269; 95% confidence interval: 1.169-13.131). The actuarial 5- and 10-year overall survivals for the first cancer was 86% and 64%, compared to 65% and 45% for the second (p = 0.0609). CONCLUSIONS: Our study shows that a surgical approach is beneficial for patients with metachronous NSCLC. Good prognosis in patients with the same histology may support the current criteria of metachronous NSCLC mainly based on the histology.

Locally infiltrative glomus tumor of the bronchus: a case report.

We report a glomus tumor of the bronchus that showed invasion of the neural area and extrabronchial extension without significant histological malignancy. The patient was a male in his late 30s with the chief complaint being hemosputum. CT revealed a nodal shadow 15 mm in diameter in the right bronchus intermedius. An irregularly protruding lesion on the tumor surface was observed by bronchoscopy immediately under the second carina in the right truncus intermedius, but could not be diagnosed because of bleeding. Sleeve lobectomy of the right upper lobe was performed, since carcinoid tumor was suspected in open chest biopsy and intraoperative frozen section diagnosis. A solid growth of spherical and cubic uniform cells with a clear eosinophilic cytoplasm and spherical nuclei was observed. Immunohistochemistry was positive for α-smooth muscle actin and type IV collagen, weakly positive for synaptophysin, and negative for keratin, neural cell adhesion molecule, chromogranin A, desmin, CD34, and S100, leading to a diagnosis of glomus tumor. Neuroinvasion and extrabronchial tumor extension were observed, but an atypical cytology, bleeding, or necrosis was found histologically. This is the first description of infiltrative glomus tumor of the bronchus.

A training session in a clinical simulation laboratory for the acquisition of clinical skills by newly recruited medical interns.

In organized orientation programs for newly recruited medical interns of the Nippon Medical School Hospital, the working committee of the clinical simulation laboratory introduced a laboratory training session that was designed to improve the clinical skills of the medical interns. The session consisted of 6 training courses, comprising internal examination, tracheal intubation, auscultation of heart sounds, bandaging and the collection of samples of venous and arterial blood. Medical interns rotated to a new course every 30 minutes and did practical trainings in each of the 6 skills. A total of 36 newly recruited medical interns participated in the training session. The majority of medical interns took part in the practical training actively and positively. The session was efficiently carried out from the standpoints of human resources and the teaching hours involved. A post training questionnaire survey, completed by the medical interns, revealed that many of them valued the sessions for comprehensibility of the instructions, the descriptions in the manual and the content of the training; however, only 21% thought that they had successfully acquired the clinical skills. Medical interns must continually engage in self-training to steadily acquire basic clinical skills. The convenience of a clinical simulation laboratory, together with the reinforcement of the education of clinical skills during internship, is necessary to strengthen the educational benefits of the training session.

Surgical results of lung cancer associated with postobstructive pneumonia.

PURPOSE: We report surgical results of lung cancer associated with postobstructive pneumonia. MATERIALS AND METHODS: We report on morbidity and mortality, and we analyze the risk factors for them and the prognostic factors for overall survival of patients without mortality. RESULTS: Morbidity developed in 13 of the 38 patients (34.2%). Mortality rate was 10.5%. Hemoglobin concentration before surgery and predicted postoperative forced expiratory volume in one second were significantly low in patients with morbidity and mortality based on the univariate analyses. Predicted postoperative forced expiratory volume in one second was a significant risk factor for morbidity based on a multivariate analysis. Poor prognostic factors for overall survival were serum albumin concentration, hemoglobin concentration, and performance status before surgery, combined resection, and pathological stage. Serum albumin concentration was significant based on a multivariate analysis. CONCLUSIONS: Morbidity and mortality are high in patients with lung cancer associated with postobstructive pneumonia. Morbidity demonstrates significant association with low predicted postoperative forced expiratory volume in one second and hemoglobin concentration, indicating the need for preoperative transfusion in severe anemia or bronchoplasty if possible. Poor nutritional state before surgery possibly derived from cachexia may influence not only morbidity and mortality, but also prognosis.

Postoperative recurrences of pneumothorax in video-assisted thoracoscopic surgery for primary spontaneous pneumothorax in young patients.

PURPOSE: The postoperative recurrence rate of pneumothorax tends to be higher with thoracoscopic bullectomy than with conventional plication of bullae by axillary thoracotomy or posterolateral thoracotomy. We analyzed the risk factors for postoperative recurrence of pneumothorax in young patients treated with thoracoscopic bullectomy alone for primary spontaneous pneumothorax. METHODS: Univariate and multivariate analyses were performed of a consecutive series of 53 patients (62 sides) who underwent video-assisted thoracoscopic bullectomy from March 1994 through March 2004. RESULTS: Pneumothorax recurred after 10 operations (16.1%). Eighty percent of postoperative pneumothorax recurrences developed within 5 months after surgery. Univariate analysis of postoperative pneumothorax recurrences revealed significant risk factors to be the early period of video-assisted thoracoscopic surgery (VATS) experience for primary spontaneous pneumothorax and a low number of pack-years (p<0.05 and p<0.05, respectively). Multivariate logistic regression test revealed that the early period of VATS experience was the single significant risk factor (odds ratio, 0.275; 95% confidence interval, 0.095-0.797; p value, 0.0174). Seventy percent of postoperative pneumothorax recurrences probably developed because of overlooked bullae and incomplete resection of bullae in the early period of VATS experience. Close observation of the pleural cavity to find bullae and bullectomy with a sufficient margin of normal pleurae and pulmonary parenchyma prevented postoperative pneumothorax recurrences significantly in the middle and recent periods. CONCLUSION: Close observation of the pleural cavity to find bullae and bullectomy with a sufficient margin of normal pleurae and pulmonary parenchyma are important measures for preventing postoperative recurrence of pneumothorax.

Inflation of the distal cuff by saline reduces the incidence of malposition of the bronchial tube during lung separation in patients receiving nitrous oxide.

BACKGROUND: A common problem during lung separation is malposition of the double-lumen tube (DLT). It was hypothesized that inflation of the distal cuff with saline instead of air may reduce the incidence of malposition of the endobronchial tube. MATERIALS AND METHODS: Fifty-two patients who were scheduled to undergo thoracic surgery with lung separation by a DLT were randomly assigned to 1 of 2 groups: the distal cuff was inflated with 2 mL of air in the air group (n = 26), whereas the distal cuff was inflated with 1.2 mL of saline in the saline group (n = 26). Anesthesia was maintained by isoflurane, 50% oxygen and nitrous oxide mixture, and incremental injection of epidural ropivacaine, 0.75%. Respiration was controlled by pressure-controlled ventilation. The peak airway pressure was maintained between 20 to 25 cmH2O. The position of the bronchial cuff was evaluated with a fiberoptic bronchoscope just after intubation and 1 and 2 hours after intubation by using a 3-point scale: 0, in exactly the same position as the previous inspection; 1, not in exactly the same position as that in the previous inspection, but there was no possibility that the tube was malpositioned; and 2, the cuff looked as if it was going to become herniated or dislodged. Signs suggesting malposition such as air leakage, high airway pressure, or inflation of the independent lung were recorded. When repositioning was required, the anesthesiologist repositioned the DLT using bronchoscopic observation or clinical signs. The endpoint of this study was the number of patients who required repositioning during surgery. RESULTS: The malposition score at 1 hour and 2 hours after intubation was comparable in the 2 groups (0.6 +/- 0.6 v 0.4 +/- 0.6 and 0.5 +/- 0.8 v 0.2 +/- 0.5, mean +/- standard deviation, air group v saline group, 1 hour and 2 hours after positioning, p = 0.27 and p = 0.33, respectively). However, a significantly higher cumulative number of air-group patients required repositioning of the tube than saline-group patients (13:6, air group:saline group, p = 0.04). CONCLUSION: Inflation of the distal cuff with saline may reduce the incidence of malpositioning of DLTs during lung separation.

Hereditary factors in multiple primary malignancies associated with lung cancer.

PURPOSE: There are differences between lung cancer alone and multiple primary malignancies associated with lung cancer (MPMLC) in terms of clinical characteristics. However, the importance of these differences has not yet been clarified. METHODS: Univariate and multivariate analyses were performed on 123 patients with MPMLC and 815 patients with lung cancer alone who underwent operative procedures for lung cancer from August 1982 to March 2004. RESULTS: Age, number of family with a family history of other malignancies except for smoking-related cancers, and pathological early stage of lung cancer were significantly high in patients with MPMLC based on univariate analyses (P < 0.0001, P < 0.05, and P < 0.05, respectively). Age and family history of malignancy were thus found to be significant factors based on a multivariate analysis. CONCLUSIONS: MPMLC demonstrated a significant association with advanced age and stronger hereditary factors in comparison with lung cancer alone, indicating the need for different approaches to properly manage and follow up risk patients.

Ciprofloxacin penetration into the pulmonary parenchyma in Japanese patients.

PURPOSE: To assess the degree of penetration of intravenous (i.v.) ciprofloxacin into the lung parenchyma resected for lung carcinoma in Japanese patients. METHODS: Ciprofloxacin was given i.v. over 1 h to ten Japanese patients with non-small cell lung carcinoma. We took 1 g of normal lung parenchyma and 1 ml of blood serum for analysis when the lung was resected. Ciprofloxacin concentrations were determined by high-performance liquid chromatography. RESULTS: The mean time from the end of ciprofloxacin administration to lung resection was 135 +/- 55 min (range, 75-223 min). The mean concentrations of ciprofloxacin in the lung parenchyma and blood serum were 4.9 +/- 2.0 microg/g (range, 2.1-7.9) and 1.5 +/- 0.7 microg/ml (range, 0.8-2.7). The mean tissue per serum concentration ratio was 3.6 +/- 2.2 (range, 1.9-8.7). CONCLUSION: The concentrations of ciprofloxacin in the lung parenchyma after i.v. administration in Japanese patients were above the minimal inhibitory concentration for bacteria from at least 75 min until 4 h later.

Characteristics of multiple primary malignancies associated with lung cancer by gender.

BACKGROUND: There are gender differences in multiple primary malignancies associated with lung cancer (MPMLC) in terms of clinical characteristics. However, the importance of these differences in the management of patients has not been clarified. OBJECTIVE: Differences in characteristics affected by gender were investigated in MPMLC to identify factors important for the proper management of the patients. METHODS: Univariate and multivariate analyses were performed between 82 male and 34 female patients with MPMLC treated from August 1982 to March 2002. RESULTS: In univariate analysis, the numbers of smokers or ex-smokers, smoking-related cancer and synchronous multiple primary malignancies were significantly increased in males with MPMLC (p < 0.0001, p < 0.05 and p < 0.05, respectively). In multivariate analysis, synchronous multiple primary malignancies and the number of smokers or ex-smokers were significantly different between male and female MPMLC. Gastric, lung and colon cancers were major constituents in male MPMLC, and 40.2% of all malignancies were smoking-related cancers. On the other hand, breast and uterine cancers were major constituents in female MPMLC, and only 20.6% of all MPMLC were smoking-related cancers. CONCLUSIONS: Male patients with MPMLC demonstrated significant smoking history and synchronous multiple primary malignancies, indicating the need for different approaches to properly manage and follow up male versus female MPMLC patients.

Dissimilarity in gene expression profiles of lung adenocarcinoma in Japanese men and women.

BACKGROUND: Although clinical differences in lung cancer between men and women have been noted, few studies have examined the sex dissimilarity using gene expression analysis. OBJECTIVE: The purpose of this study was to determine the different molecular carcinogenic mechanisms involved in lung cancers in Japanese men and women. METHODS: Patients who received surgery for stage I lung adenocarcinoma were included. RNA was extracted from cancerous and normal tissue, and gene expression was then examined with oligonucleotide microarray analysis. A quantitative polymerase chain reaction assay was performed. RESULTS: In a microarray analysis of tissue from 13 men and 6 women, 12 genes were under-expressed and 24 genes were overexpressed in lung adenocarcinoma in women compared with men. Genes related to cell cycle were present in underexpressed genes, and genes related to apoptosis, ubiquitination, and metabolism were observed in overexpressed genes. Of interest among the selected genes were WAP four-disulfide core domain 2 (WFDC2) and major histocompatibility complex, class II, DM alpha (HLA-DMA); these genes were classified into 2 groups by hierarchical clustering analysis. Expression of WFDC2 in nonsmokers was significantly higher than that in smokers (P=0.023). However, there was no significant difference in HLA-DMA expression between smokers and nonsmokers. CONCLUSION: Thirty-six genes that characterize lung adenocarcinoma by sex were selected. This information may contribute to the development of novel diagnostic techniques and treatment modalities that consider sex differences in lung adenocarcinoma.

Enucleation of esophageal leiomyoma with azygos continuation of the inferior vena cava: report of a case.

We herein report a rare case of esophageal leiomyoma in an 18-year-old woman with azygos continuation of the inferior vena cava. A submucosal tumor was located in the left wall of the esophagus behind the carina. The enlarged azygos vein made video-assisted thoracic surgery so difficult that conversion to a minithoracotomy and transection of the right superior intercostal vein were necessary to fully visualize the tumor. A pathological diagnosis revealed leiomyoma. Our experience suggests that a transection of the right superior intercostal vein is effective for the proper exposure of an esophageal tumor located behind the carina in a patient with an enlarged azygos vein.

Metastatic chest wall tumor suspected to be of lung origin by immunoreactivity for cytokeratin 7 and 20.

We report a rare case of unknown primary carcinoma. A 36-year-old man was admitted to the hospital because of a chest wall tumor. Serum carcinoembryonic antigen level was 160 ng/ml. The resected chest wall tumor was pathologically diagnosed as metastatic adenocarcinoma, showing positive immunoreactivity for cytokeratin 7 and negative immunoreactivity for cytokeratin 20, suggesting lung origin. Serum carcinoembryonic antigen level returned to normal limits. Twenty-one months later, a chest X-ray showed a nodular lesion in the left upper lobe and serum carcinoembryonic antigen level increased to 12.3 ng/ml. Left upper lobectomy was performed 23 months after chest wall resection. The resected tumor was pathologically diagnosed as primary lung adenocarcinoma, showing the same immunoreactivity as in the chest wall tumor. The combination of immunohistochemistry for cytokeratin 7 and 20 appeared to be a useful tool in determining the site of origin and helpful for premortem diagnosis of the origin of unknown primary carcinoma.