Clinical and Pathophysiological Features of High-altitude Pulmonary Edema in the Japanese Population: A Review of Studies on High-altitude Pulmonary Edema in Japan.

High-altitude pulmonary edema (HAPE) is a life-threatening, noncardiogenic pulmonary edema that occurs in unacclimatized individuals rapidly ascending to high altitudes above 2,500 m above sea level. Until the entity of HAPE was first identified in a case report published in Japan in 1966, the symptoms of severe dyspnea or coma occurring in climbers of the Japan Alps were incorrectly attributed to pneumonia or congestive heart failure. The Shinshu University Hospital serves as the central facility for rescuing and treating patients with HAPE in the region. Over the past 50 years, a series of studies have been conducted at Shinshu University to gain a better understanding of the characteristics of HAPE. This review summarizes the major achievements of these studies, including their clinical features, management, and pathogenesis of HAPE, particularly in the Japanese population.

EGFR-TKI rechallenge in patients with EGFR-mutated non-small-cell lung cancer who progressed after first-line osimertinib treatment: A multicenter retrospective observational study.

BACKGROUND: Rechallenge therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is known to confer some clinical benefit for patients with metastatic EGFR-mutated non-small cell lung cancer (NSCLC). However, little is known about the efficacy of EGFR-TKI rechallenge after resistance to first-line (1L) osimertinib. This study aimed to assess the efficacy and safety of EGFR-TKI rechallenge therapy after resistance to 1L osimertinib in a Japanese clinical setting. METHODS: Between April 2018 and August 2022, 26 patients who progressed after treatment with 1L osimertinib and received EGFR-TKI rechallenge were included in this multicenter retrospective analysis. Patients in whom 1L osimertinib was discontinued owing to toxicity and had subsequent disease progression were also included in the analysis. RESULTS: Overall, the objective response rate for rechallenge therapy was 23.1%. The disease control rate was 53.9%, and the median progression-free survival (PFS) was 3.4 months. Patients who discontinued 1L osimertinib for toxicity had a higher response rate (42.9% vs. 15.8%) and longer PFS than those who discontinued it due to disease progression (median: 11.4 vs. 2.7 months, P = 0.001). Three patients (11.5%) developed rechallenge therapy-associated pneumonitis, two of which were grade ≥3. CONCLUSIONS: Rechallenge with EGFR-TKI after 1L osimertinib resistance showed limited clinical efficacy. However, it could be considered as a subsequent salvage therapeutic option for patients in whom 1L osimertinib was discontinued owing to toxicity.

Pleomorphic Liposarcoma Initially Presenting with Multiple Organ Involvement Including the Heart.

A 42-year-old man visited our hospital due to a gradually swelling subcutaneous mass on the back of the right shoulder. The biopsy specimen was diagnosed pathologically as pleomorphic liposarcoma. Systemic computed tomography and 18F-fluorodeoxyglucose positron emission tomography revealed multiple organ metastases, including involvement of the heart, skin, liver, bone, and lung. Six cycles of doxorubicin plus ifosfamide initially controlled the disease. However, newly developed lung metastases grew rapidly during subsequent cycles of chemotherapy, and the patient died 10 months after the initial diagnosis. The initial presentation of multiple organ involvement, including the heart, is a rare clinical manifestation of pleomorphic liposarcoma.

Epidemiological and therapeutic profiles of lung cancer patients in the Hokushin Region Japan: a retrospective hospital administrative database study.

OBJECTIVE: This study was performed to validate the epidemiology, initial treatment, and clinical practice of lung cancer patients in the Hokushin region, Japan. METHODS: We retrospectively surveyed data of 5503 newly diagnosed and registered lung cancer patients in 22 principal hospital-based cancer registries in Hokushin region linked with health insurance claims data for registered patients between 2016 and 2017. RESULTS: The patients consisted of 3677 (66.8%) men and 1826 (33.2%) women with a mean (range) age of 72.2 (27-103) years). Diagnoses were small cell lung cancer (n = 512, 9.4%), squamous cell carcinoma (n = 1083, 19.7%), and non-squamous non-small cell lung cancer (NSCLC; n = 3906, 70.9%). The population with stage I disease in Toyama prefecture (41.1%) was smaller than in the other three prefectures associated with reduced selection of initial surgical therapy and increased frequencies of stage IV disease (33.2%) and best supportive care (18.6%). Initial chemotherapy for stage IV non-squamous NSCLC consisted of tyrosine kinase inhibitors in 39.3% of cases for EGFR and 4% of cases for ALK-positive non-squamous NSCLC, followed by platinum compounds (25.9%) non-platinum compounds (12.9%), and immune checkpoint inhibitors (10.2%). Carboplatin was the commonly prescribed first-line cytotoxic chemotherapeutic agent (65.4% of patients under 75 years and in 96.7% of patients over 75 years). CONCLUSION: This study revealed real-world data on epidemiological and treatment status in lung cancer in four prefectures in Hokushin region, Japan. Simultaneous analysis of nationwide registry and insurance data could provide valuable insights for the development of lung cancer screening and medical treatment strategies. In addition, the comparative data analysis with other lesions or countries will be useful for evaluating the differences in clinical practice of cancer managements.

Rechallenge of afatinib for EGFR-mutated non-small cell lung cancer previously treated with osimertinib: a multicenter phase II trial protocol (REAL study).

Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of advanced non-small cell lung cancer (NSCLC) and contributed to the development of precision medicine. Osimertinib is a standard first-line (1L) treatment for EGFR-mutated NSCLC and has demonstrated superior survival benefits over previous-generation TKIs. However, resistance to osimertinib is nearly inevitable, and subsequent treatment strategies remain unmet medical needs in this setting. Afatinib, a second-generation EGFR-TKI, exhibits activity against certain uncommon EGFR mutation types in the 1L setting. There are a few case reports on the efficacy of afatinib against EGFR-dependent resistance after osimertinib treatment, although these have not been prospectively investigated. Methods: The present phase II, single-arm multicenter trial aims to verify the efficacy and safety of afatinib rechallenge after 1L osimertinib resistance. Patients (aged ≥20 years) with advanced or recurrent non-squamous NSCLC harboring drug-sensitive EGFR mutations (deletion of exon 19 or L858R) who were previously treated with 1L osimertinib and second-line chemotherapy other than TKIs are considered eligible. Undergoing next-generation sequence-based comprehensive genomic profiling is one of the key inclusion criteria. The primary endpoint is the objective response rate; the secondary endpoints are progression-free survival, overall survival, and tolerability. Thirty patients will be recruited in December 2023. Discussion: The results of this study may promote incorporating afatinib rechallenge into the treatment sequence after 1L osimertinib resistance, a setting in which concrete evidence has not been yet established. Registration: UMIN Clinical Trial Registry: UMIN000049225.

Multi-institutional survey of antiemetic therapy in lung cancer patients treated with carboplatin in Hokushin region.

OBJECTIVE: Appropriate monitoring and management of chemotherapy-induced nausea and vomiting (CINV) with prophylactic antiemetics is important for cancer patients. This study was performed to validate the clinical practice of antiemetic use with carboplatin-based chemotherapy in lung cancer patients in the Hokushin region (Toyama, Ishikawa, Fukui, and Nagano prefectures), Japan. METHODS: We surveyed retrospective data of newly diagnosed and registered lung cancer patients initially treated with carboplatin-based chemotherapy in 21 principal hospitals in the Hokushin region linked with health insurance claims data between 2016 and 2017. RESULTS: A total of 1082 lung cancer patients (861 [79.6%] men, 221 [20.4%] women; median age 69.4 years [range, 33-89 years]). All patients received antiemetic therapy, with 613 (56.7%) and 469 patients (43.3%) receiving 5-hydroxytryptamine-3 receptor antagonist/dexamethasone double regimen and 5-hydroxytryptamine-3 receptor antagonist/dexamethasone/neurokinin-1 receptor antagonist triple regimen, respectively. However, the rates of double regimen and use of palonosetron were higher in Toyama and Fukui prefectures. Thirty-nine patients (3.6%) changed from double to triple regimen, while 41 patients (3.8%) changed from triple to double regimen after the second cycle, but six of these returned to triple antiemetics in subsequent cycles. CONCLUSION: Adherence to antiemetic guidelines in clinical practice was high in Hokushin region. However, rates of double and triple antiemetic regimens differed between the four prefectures. Simultaneous analysis of nationwide registry and insurance data was valuable for evaluating and comparing the differences in the status of antiemesis and management.

Successful resection after first-line lenvatinib therapy in an advanced thymic carcinoma.

Thymic carcinoma is a highly malignant tumor and treatment options are limited. Lenvatinib, a novel multitargeted kinase inhibitor, has recently been approved for the treatment of unresectable thymic carcinoma. There are no reports of complete surgical resection after the administration of first-line lenvatinib in advanced thymic carcinoma. A 50-year-old man visited our hospital because a computed tomography (CT) scan of the chest showed a large thymic squamous cell carcinoma. We suspected malignant pericardial effusion, invasion of the left upper lobe of the lung, and left mediastinal lymph node metastases. The patient was diagnosed with WHO classification stage IVb disease. Lenvatinib therapy was started at 24 mg/day as first-line therapy. Gradual dose reduction to 16 mg/day was required because of hypertension, diarrhea, and palmar-plantar erythrodysesthesia syndrome as side effects. Chest CT findings after 6 months of lenvatinib therapy showed reduction of the main tumor, disappearance of the mediastinal lymph node metastases, and pericardial effusion. Complete salvage resection was successfully performed a month after discontinuation of lenvatinib. The patient has been disease-free for 1 year without adjuvant therapy. Lenvatinib therapy is one of the promising therapeutic options for thymic carcinoma and may make salvage surgery increasingly useful for advanced thymic carcinoma.

A case of mediastinal mesenchymal tumor with pericytic neoplasm feature that responded to radiation therapy.

Here, we report a case of mediastinal mesenchymal tumor with a pericytic neoplasm feature that responded to radiation therapy. A 43-year-old man visited our hospital with a complaint of esophageal obstruction and chest pain. Chest computed tomography revealed a middle mediastinal tumor and a mesenchymal tumor was diagnosed with a pericytic neoplasm feature by video-assisted thoracoscopic biopsy. The definitive treatment for soft tissue tumor is surgical resection; however, the mediastinal tumor was unresectable because of esophageal and tracheal invasion. Radiation therapy was administered and there was a partial tumor response and 2 years disease-free status. With a review of the literature, we discuss the clinical and pathological characteristics of this rare tumor and its treatment.

Hereditary diffuse gastric cancer in a Japanese family with CDH1 mutation three case reports.

BACKGROUND: Germline pathogenic variants in the E-cadherin gene CDH1 cause hereditary diffuse gastric cancer (HDGC), which is an autosomal dominant cancer syndrome, accounting for 1-3% of all gastric cancers. HDGC harboring a CDH 1 variant is extremely rare in Japan. METHOD: In this study we report the clinical courses of three cases with HDGC from a single Japanese family. RESULTS: The proband exhibited advanced and metastatic gastric cancer, and was found to have a previously reported heterozygous frameshift variant in CDH1 (NM_004360.3:c.1009_1010del:p.Ser337Phefs*12). Five at-risk relatives underwent presymptomatic molecular testing after careful genetic counseling, and three were molecularly diagnosed as positive for the variant. Esophagogastroduodenoscopy was performed in these relatives revealing abnormal small pale mucosal patches, small ulcerative lesion and no abnormal findings. Moreover, random and targeted biopsies were compatible with pathological diagnosis of HDGC in the three cases, all of which underwent total prophylactic gastrectomy. CONCLUSION: It is critical for the assessment and management of HDGC patients to be actively offered a multidisciplinary and familial-oriented approach. Notably, genetic screening in suspected individuals and familial members is a determining piece for a higher detection rate and the identification of clinical relevant mutations in both low and high-incidence gastric cancer countries.

Epidemiological and Therapeutic Analyses in Lung Cancer Patients Over 80 Years Old in the Hokushin Region: A Retrospective Hospital Administrative Database Study.

OBJECTIVE: This study was performed to validate the epidemiology, initial treatment, and clinical practice in lung cancer patients < 80 and ≥ 80 years in Hokushin region, Japan. METHODS: We retrospectively surveyed data of 5481 newly diagnosed and registered lung cancer patients (4311 [78.7%] < 80 years; 1170 [21.3%] ≥ 80 years ) in 22 principal hospitals in Hokushin region linked with health insurance claims data between 2016 and 2017. Stage, initial treatment, and clinical practice were compared between the 2 groups. RESULTS: The distributions of clinical stage I/II/III/IV/unknown were 2535/387/654/1371/111 in non-small cell lung cancer (NSCLC) and 37/32/114/237/3 in SCLC. Initial surgery for stage I NSCLC was performed in 90.0% and 60.2% of cases in the < 80 and ≥ 80 years groups, respectively. Rates of treatment with best supportive care (BSC) for stage IV disease were significantly higher in the ≥ 80 than the < 80 years group (NSCLC:58.9% vs. 18.7%; SCLC: 42.3% vs. 6.8%, respectively), regardless of the presence/absence of comorbidities. Propensity score matching showed that age ≥ 80 years itself was significantly related to choice of BSC in patients with lung cancer. The ratio of initial cytotoxic chemotherapy for NSCLC was low (49.9%) but that of biomarker-based therapy including tyrosine kinase inhibitors and immune checkpoint inhibitors (50.0%) was significantly higher in the ≥ 80 than < 80 years group (70.2% vs. 29.8%, respectively). CONCLUSION: There are several differences in treatment pattern between patients < 80 and ≥ 80 years. Age ≥ 80 years may be related to BSC choice in patients with lung cancer.

EGFR inhibition in EGFR-mutant lung cancer cells perturbs innate immune signaling pathways in the tumor microenvironment.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) elicit potent cell cycle arrest in EGFR-mutant non-small-cell lung cancer (NSCLC) cells. However, little is known about the mechanisms through which these drugs alter the tumor phenotype that contributes to the immune escape of EGFR-mutant cells. Using EGFR-mutant NSCLC cell lines and tissue samples from patients, we investigated the changes in immune checkpoints expressed in tumor cells following EGFR inhibition. Subsequently, we also analyzed the role of soluble factors from the dying tumor cells in the activation of immune signaling pathways involved in therapy resistance. Upon EGFR-TKI treatment, we found that EGFR-mutant cells upregulated the expression of innate immune checkpoint CD24 in vitro. We then analyzed biopsy samples from six patients who developed resistance to a first-generation EGFR-TKI without the acquired T790M mutation. Immunohistochemistry revealed that levels of tumor CD24 expression were increased upon treatment compared with those from pre-treatment samples. Monocyte-derived macrophages facilitated antibody-dependent cellular phagocytosis when EGFR-TKI-treated EGFR-mutant cells were incubated with anti-CD24 antibodies in vitro, suggesting that CD24 may be a therapeutical target for EGFR-mutant lung cancer. Moreover, EGFR inhibition accelerated the release of cell-free DNA (cfDNA) from dying tumor cells, which activated the type I interferon signaling pathways in human THP-1 monocytes in a stimulator of interferon genes-dependent manner. Our study indicates that EGFR inhibition in EGFR-mutant NSCLC cells fosters a tumor microenvironment associated with immune escape. Thus, CD24 targeted therapy and cfDNA monitoring may contribute to improved treatment outcomes in patients with EGFR-mutant NSCLC.

Initial Therapeutic Approach with Pembrolizumab in Synchronous Multiple Cancers, Including Non-Small Cell Lung Cancer, Highly Positive for Programmed Death-Ligand 1 Expression.

Treatment of synchronous multiple primary cancers is clinically difficult. We report four cases of synchronous primary cancers, including advanced and metastatic non-small cell lung cancer (NSCLCs) highly positive for programmed death ligand-1 (PD-L1) expression and initially treated with pembrolizumab. Pembrolizumab was efficacious in 2 patients with NSCLC lesions, followed by chemoradiotherapy for esophageal cancer (case 1) and chemotherapy for gastric cancer (case 2). Both cancers in case 1 showed a complete response for 3 years, while progression of the accompanying gastric cancer resulted in mortality at 20 months in case 2. Both NSCLC and gastric cancer in case 3 failed to respond to pembrolizumab, but the accompanying laryngeal cancer in case 4 showed a complete response, and cytotoxic chemotherapy for NSCLC was continued for 18.0 months. Our clinical experience suggests that pembrolizumab is a useful therapeutic approach for patients with synchronous cancers, including NSCLC that highly expresses PD-L1.

Clinical Analysis of Extrapulmonary Neuroendocrine Carcinoma: A Retrospective and Single Institution Experience.

INTRODUCTION: Extrapulmonary neuroendocrine carcinoma (EPNEC) is a clinicopathological entity distinct from neuroendocrine carcinoma of the lung. Here, we reviewed the clinical features, treatment modalities, and prognosis of EPNEC patients in a single-institution series. METHODS: We retrospectively reviewed the medical records of EPNEC patients and examined the clinical profiles and treatment outcomes at our hospital between 2013 and 2021. RESULTS: Thirty-one EPNEC patients (21 men and 10 women) with a median age of 65 years were included. The primary sites were as follows: stomach (n = 7); rectum and bladder (n = 3 each); prostate, esophagus, cervix, and pancreas (n = 2 each); maxillary sinus, parotid gland, gallbladder, anal canal, larynx, uterine body, ovary, appendix, anterior mediastinum, and unknown primary lesion (n = 1 each). Thirteen patients had locally advanced stage and 18 cases had distant metastases. Chemotherapy using platinum-combined CPT-11 or VP-16 was mainly performed. Various therapeutic modalities were used, especially in locally advanced cases. Ten patients underwent surgery, including initial surgery in 5 and conversion in 5 after chemotherapy. The response rate to initial chemotherapy was 56.5%, and the median overall survival in all patients was 12.8 (95% CI: 9.6-34.5) months. Survival was significantly longer in patients with locally advanced stage (80.3 months) and receiving surgery (not reached) than in those with metastatic disease (9.9 months) and without surgery (9.6 months). CONCLUSION: EPNEC occurs in various organs and has poor prognosis. Long-term survival may be possible with surgical resection in cases with early-stage disease or tumor shrinkage due to chemotherapy.

Gastric Cancer After Helicobacter pylori Eradication for Nodular Gastritis in an Adolescent.

A 16-year-old girl underwent esophagogastroduodenoscopy (EGD) after the detection of Helicobacter pylori (H. pylori) antibodies in her urine during a school health screening, which revealed nodular gastritis (NG). She was diagnosed as having H. pylori infection histologically and by biopsy culture specimens and soon commenced eradication therapy. Eight weeks later, eradication was confirmed by a urea breath test. At the age of 19, however, she was referred to our hospital with epigastralgia and lower back pain. EGD revealed ulcerative lesions with enlarged folds at the greater curvature of the gastric body. Biopsy specimens of the lesions revealed poorly differentiated adenocarcinoma and signet ring cell carcinoma. The cancer was classified as stage IV with pancreatic invasion. Although NG with pangastritis is considered a high-risk factor for diffuse-type gastric carcinoma, the course of NG after eradication remains unknown. Careful histological assessment before eradication by endoscopic biopsy and close follow-up after eradication are therefore recommended, even in young patients.

Republication: Targeting PI3KC2ß Impairs Proliferation and Survival in Acute Leukemia, Brain Tumours and Neuroendocrine Tumours.

BACKGROUND: Eight human catalytic phosphoinositide 3-kinase (PI3K) isoforms exist which are subdivided into three classes. While class I isoforms have been well-studied in cancer, little is known about the functions of class II PI3Ks. MATERIALS AND METHODS: The expression pattern and functions of the class II PI3KC2ß isoform were investigated in a panel of tumour samples and cell lines. RESULTS: Overexpression of PI3KC2ß was found in subsets of tumours and cell lines from acute myeloid leukemia (AML), glioblastoma multiforme (GBM), medulloblastoma (MB), neuroblastoma (NB), and small cell lung cancer (SCLC). Specific pharmacological inhibitors of PI3KC2ß or RNA interference impaired proliferation of a panel of human cancer cell lines and primary cultures. Inhibition of PI3KC2ß also induced apoptosis and sensitised the cancer cells to chemotherapeutic agents. CONCLUSION: Together, these data show that PI3KC2ß contributes to proliferation and survival in AML, brain tumours and neuroendocrine tumours, and may represent a novel target in these malignancies.

Successful management of testicular primitive neuroectodermal tumor with multiple bone metastases.

Introduction: Germ cell tumor with malignant transformation is extremely rare. We present a case of testicular primitive neuroectodermal tumor with multiple metastases that was effectively managed by surgery, irradiation, and second-line chemotherapy. Case presentation: A 22-year-old man was diagnosed as having teratoma including primitive neuroectodermal tumor with lymph node and multiple bone metastases. Five months afterwards the first-line therapy, his skull metastasis recurred. Vincristine, doxorubicin, and cyclophosphamide therapy followed by vincristine, actinomycin D, and cyclophosphamide therapy was given as second-line chemotherapy. Computed tomography revealed no disease progression 3 months after the treatments. Conclusion: Metastatic primitive neuroectodermal tumor may be successfully managed by multidisciplinary cancer treatment.

Predictive value of post-treatment C-reactive protein-to-albumin ratio in locally advanced non-small cell lung cancer patients receiving durvalumab after chemoradiotherapy.

BACKGROUNDS: The PACIFIC trial established durvalumab consolidation therapy after concurrent chemoradiotherapy (CCRT) as the standard treatment for locally advanced non-small cell lung cancer (LA-NSCLC). However, little is known about the predictive factors of durvalumab efficacy in this population. This study aimed to validate the predictive use of inflammation-related parameters in patients with LA-NSCLC treated with CCRT plus durvalumab. METHODS: We recruited 76 LA-NSCLC patients who received CCRT followed by durvalumab from 10 Japanese institutions. The neutrophil-to-lymphocyte ratio (NLR), C-reactive protein-to-albumin ratio (CAR), and prognostic nutrition index (PNI) were measured before (pre-treatment) and 2 months after (post-treatment) durvalumab induction. Cox proportional hazards analysis was used to examine prognostic factors associated with progression-free survival (PFS) after durvalumab therapy. RESULTS: The median follow-up time was 17 (range, 3.3-35.8) months. The median PFS and overall survival (OS) times were 26.1 and 33.7 months, respectively. Durvalumab was discontinued in 47 (61.8%) patients, with non-infectious pneumonitis being the most common reason. Post-treatment CAR (cutoff, 0.2) was a significant stratifying factor in survival comparison (<0.2 vs. ≥ 0.2, median PFS, not-reached vs. 9.6 months. Log-rank, p = 0.002). Multivariate analysis with a Cox proportional hazards model showed that post-treatment CAR was an independent prognostic factor for PFS (hazard ratio, 3.16, p = 0.003). CONCLUSIONS: This study suggests that post-treatment CAR has predictive value for LA-NSCLC patients treated with CCRT plus durvalumab consolidation therapy.

Epidemiology of neuroendocrine neoplasmas in Japan: based on analysis of hospital-based cancer registry data, 2009†-†2015.

PURPOSE: Neuroendocrine neoplasms are rare disease and could originate from throughout the body, however, there have been little epidemiological studies in Japan, especially the organ distribution. This study was to examine the epidemiological information of neuroendocrine neoplasms in the Japanese population using data from a hospital-based cancer registry. METHODS: Using data from the national database of hospital-based cancer registries, we examined the organ distribution, the stage and initial treatment of neuroendocrine neoplasms newly diagnosed and treated in designated and non-designated cancer care hospitals between 2009 and 2015. In the present study, neuroendocrine neoplasms consisted of neuroendocrine tumors and carcinoma. RESULTS: A total of 33,215 (17,485 neuroendocrine carcinomas and 15,730 neuroendocrine tumors) cases were diagnosed. The majority in neuroendocrine carcinoma occur in lung (31.1%) followed in decreasing frequency by stomach (12.9%), pancreas (7.5%), rectum (6.7%) and esophagus (5.8%). On the other hand, the half of neuroendocrine tumor originated rectum (50.9%) and followed by pancreas (13.9%), duodenum (9.0%), lung/bronchus (8.9%), and stomach (8.7%). Neuroendocrine carcinoma presented at more advanced stage and higher age than neuroendocrine tumors.　Most cases of neuroendocrine tumors were treated surgically, while half of neuroendocrine carcinomas were treated with non-surgical therapy consisting of chemotherapy with or without radiotherapy. CONCLUSIONS: Our results demonstrated that neuroendocrine neoplasms could originate from various organs and the site distribution was different between neuroendocrine carcinoma and tumor. The national database of hospital-based cancer registries in Japan is a valuable source for evaluating the organ distribution of the rare systemic disease.

Syndrome of Inappropriate Antidiuretic Hormone Secretion as the Initial Presentation in a Patient with Stage I Small-cell Lung Cancer.

A 67-year-old man with a history of esophageal cancer resection was referred to our hospital because of nausea and appetite loss. Laboratory findings showed severe hyponatremia and were compatible with syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Chest computed tomography (CT) revealed a nodule measuring 13 mm in the lower lobe of the right lung. Right thoracotomy was performed, and the histopathological diagnosis was small-cell lung cancer (T1bN0M0; Stage 1b). Although SIADH is frequently associated with small-cell lung cancer, it is extremely rare as the initial clinical feature in stage I small-cell lung cancer.

Successful Radiotherapy of Primary Malignant Peripheral Nerve Sheath Tumor of the Lung.

A 71-year-old man presented with cough and bloody sputum. Computed tomography showed a mass in the lower lobe of the left lung. Histological findings in biopsy tissue revealed a malignant peripheral nerve sheath tumor (MPNST). The patient was diagnosed with primary lung MPNST based on a systemic examination. Although initial chemotherapy treatment with doxorubicin failed to control the disease, radiotherapy considerably shrank the tumor. Primary lung MPNSTs are rare, and there is no established treatment for inoperable cases. This case suggests that radiotherapy is a treatment option for primary lung MPNST.