Pulmonary enteric adenocarcinoma.

A 70-year-old man was referred to our department due to abnormal shadows on a chest radiograph. Computed tomography of the chest revealed a 3-cm nodule in the right middle lung lobe, and bronchoscopy revealed adenocarcinoma cells with EGFR mutations. A lung resection was performed. Histological analysis revealed tumors comprising tall columnar cells that were similar to an adenocarcinoma of the sigmoid colon that had been resected 13 years previously. Metastatic colorectal carcinoma was initially considered, but immunohistochemical staining indicated pulmonary enteric adenocarcinoma. Pulmonary enteric adenocarcinoma was first described in 1991, and about 30 cases have since been described in the English literature. However, its concept and etiology are not clear. It is important to distinguish pulmonary enteric adenocarcinoma from metastatic colorectal carcinoma because of obvious differences in therapeutic strategies and prognosis, especially with a past history of colorectal carcinoma. Immunohistochemical and gene mutation analyses seemed to be helpful.

Thoracoscopic resection of congenital cystic adenomatoid malformation in an adolescent.

Congenital cystic adenomatoid malformation (CCAM) in adolescents or adults is extremely rare. In this case study, a 17-year-old boy was admitted to our clinic for the treatment of a giant bulla in the lower lobe of the right lung. Preoperative imaging studies led to the diagnosis of cystic lung disease. The patient underwent wedge resection of the right lower lobe with VATS, and histological examination confirmed the presentation of type 1 CCAM. A thoracoscopic lobectomy was performed after the second surgery because of postoperative air leakage.Herein, we report a case of CCAM in an adolescent. VATS was a suitable procedure for the operation. Between the parenchyma-saving resection and lobectomy for CCAM, we believe that the lobectomy is the better treatment option when the extent of the disease cannot be determined clearly or it is extremely large. Therefore, strategies for deciding between parenchyma-saving resection and lobectomy for the treatment of CCAM should be developed.

Radiation and smoking effects on lung cancer incidence by histological types among atomic bomb survivors.

While the risk of lung cancer associated separately with smoking and radiation exposure has been widely reported, it is not clear how smoking and radiation together contribute to the risk of specific lung cancer histological types. With individual smoking histories and radiation dose estimates, we characterized the joint effects of radiation and smoking on type-specific lung cancer rates among the Life Span Study cohort of Japanese atomic bomb survivors. Among 105,404 cohort subjects followed between 1958 and 1999, 1,803 first primary lung cancer incident cases were diagnosed and classified by histological type. Poisson regression methods were used to estimate excess relative risks under several interaction models. Adenocarcinoma (636 cases), squamous-cell carcinoma (330) and small-cell carcinoma (194) made up 90% of the cases with known histology. Both smoking and radiation exposure significantly increased the risk of each major lung cancer histological type. Smoking-associated excess relative risks were significantly larger for small-cell and squamous-cell carcinomas than for adenocarcinoma. The gender-averaged excess relative risks per 1 Gy of radiation (for never-smokers at age 70 after radiation exposure at age 30) were estimated as 1.49 (95% confidence interval 0.1-4.6) for small-cell carcinoma, 0.75 (0.3-1.3) for adenocarcinoma, and 0.27 (0-1.5) for squamous-cell carcinoma. Under a model allowing radiation effects to vary with levels of smoking, the nature of the joint effect of smoking and radiation showed a similar pattern for different histological types in which the radiation-associated excess relative risk tended to be larger for moderate smokers than for heavy smokers. However, in contrast to analyses of all lung cancers as a group, such complicated interactions did not describe the data significantly better than either simple additive or multiplicative interaction models for any of the type-specific analyses.

Radiation and smoking effects on lung cancer incidence among atomic bomb survivors.

While radiation increases the risk of lung cancer among members of the Life Span Study (LSS) cohort of atomic bomb survivors, there are still important questions about the nature of its interaction with smoking, the predominant cause of lung cancer. Among 105,404 LSS subjects, 1,803 primary lung cancer incident cases were identified for the period 1958-1999. Individual smoking history information and the latest radiation dose estimates were used to investigate the joint effects of radiation and smoking on lung cancer rates using Poisson grouped survival regression methods. Relative to never-smokers, lung cancer risks increased with the amount and duration of smoking and decreased with time since quitting smoking at any level of radiation exposure. Models assuming generalized interactions of smoking and radiation fit markedly better than simple additive or multiplicative interaction models. The joint effect appeared to be super-multiplicative for light/moderate smokers, with a rapid increase in excess risk with smoking intensity up to about 10 cigarettes per day, but additive or sub-additive for heavy smokers smoking a pack or more per day, with little indication of any radiation-associated excess risk. The gender-averaged excess relative risk per Gy of lung cancer (at age 70 after radiation exposure at 30) was estimated as 0.59 (95% confidence interval: 0.31-1.00) for nonsmokers with a female : male ratio of 3.1. About one-third of the lung cancer cases in this cohort were estimated to be attributable to smoking while about 7% were associated with radiation. The joint effect of smoking and radiation on lung cancer in the LSS is dependent on smoking intensity and is best described by the generalized interaction model rather than a simple additive or multiplicative model.

[Case of pulmonary dirofilariasis with cavity formation in a young woman].

A 22-year-old woman was referred to our hospital because of an abnormal shadow in her chest X-ray found on a medical examination. Chest CT showed a 16-mm nodule with cavity formation in the left lung. We did not reach a definitive diagnosis by blood test and bronchoscopy. Because we could not exclude the possibility of a malignancy, lung partial resection was performed by video-assisted thoracoscopic surgery for treatment and diagnosis. We recognized the Dirofilaria immitis by pathological diagnosis and we diagnosed this case as pulmonary dirofilariasis. It seemed to be a valuable case that the patient was young, at 22 years old, and there was, cavity formation, which is comparatively rare in pulmonary dirofilariasis.

[A case of thoracolithiasis].

Many kinds of tumor shadows have been reported on chest X rays in recent years, some of which are difficult to diagnose. A 72-year-old man was admitted to our hospital for further tests, because of an abnormal shadow recorded on a chest X ray on a routine health examination. Chest CT scan demonstrated a round mass lesion, about 2cm in diameter, at the pleural surface of the S6 segment of the right lung. Our attempt at CT guided percutaneous lung needle biopsy failed because the needle was unable to penetrate the tumor, resulting in right pneumothorax. Later, a tumor was located in the basal part of the right lung, which was confirmed by CT scan. Video-assisted thoracic surgery (VATS) was performed, and a white 2-cm nodule in the right pleural cavity and two grayish-white 2-3-mm nodules on the right pleural surface were removed. The cut surfaces of these nodules showed a small black core surrounded by white concentric structures. Histologically, a small quantity of coal dust and many histiocyte-like cells were found in the core, surrounded by acidophilic fibrous connective tissue. These findings were consistent with thoracolithiasis, which is a rare disorder but one that requires diagnostic differentiation from peripherally located lung tumors.

[A case of primary mediastinal choriocarcinoma].

A 30-year-old man presented with cough and bloody sputum. He brought a chest radiogram showing abnormal findings. His chest computed tomography revealed a large mediastinal mass and multiple nodular shadows in both lungs. The serum beta-HCG level was remarkably elevated, and physical examination revealed bilateral gynecomastia and right supraclavicular lymph node swelling. His lymph node was biopsied and choriocarcinoma was diagnosed. After 3 cycles of BEP therapy (cisplatin, etoposide, bleomycin), the tumors regressed and the serum beta-HCG level decreased. Although there were residual tumors and serum beta-HCG was mildly elevated, he refused additional therapy. The choriocarcinoma progessed rapidly again and he died seven months after his first visit. Primary mediastinal germ cell tumors are rare, and in particular the pure type of choriocarcinoma arising in the mediastinum is even rarer. Patients with mediastinal choriocarcinoma are mostly young men. The prognosis of primary mediastinal choriocarcinoma is still very poor despite the introduction of combination chemotheraphy including cisplatin. We report a case of primary mediastinum pure choriocarcinoma. Chemotherapy was effective for the patient, but he died because of recurrence after refusal of future treatment. Establishment of more effective treatment is necessary.