Since the pathobiology of malignant mediastinal tumors is complex, their diagnosis and treatment differ by disorder. In this review, the definitive diagnosis and multimodality treatment, including surgery, drug therapy, and irradiation, are reviewed based on the clinical guidelines, trials, research, and characteristic comorbidities of malignant mediastinal tumors, focusing on thymoma, thymic carcinoma, thymic neuroendocrine tumor, and malignant mediastinal germ cell tumors.

Background/Aim. Immune checkpoint inhibitors (ICIs) plus platinum-based chemotherapy is the recommended first-line treatment for advanced non-small-cell lung cancer (NSCLC). However, which biomarkers are useful for predicting the efficacy of ICIs plus chemotherapy is unclear. We therefore explored biomarkers that may predict the progression-free survival (PFS) following treatment with ICIs plus chemotherapy. Patients and Methods. We retrospectively reviewed 85 patients with NSCLC who received ICIs plus platinum-based chemotherapy between January 2019 and July 2021. The association between biomarkers and the effect of the therapy on the PFS was investigated. Results. Multivariable COX regression analyses revealed that a pretreatment modified Glasgow prognostic score (mGPS) of 2 (hazard ratio [HR]: 1.76, p=0.004), an albumin-globulin ratio (AGR) <1.4 (HR: 2.57, p=0.016), and an advanced lung cancer inflammation index (ALI) <10.1 (HR: 2.20, p=0.041) were associated with a poor PFS. Conclusion. The mGPS, AGR, and ALI may be useful predictive factors for ICIs plus platinum-based chemotherapy in NSCLC.

Background. Axillary lymphadenopathy after COVID-19 vaccination have been frequently reported in the medical literature. This benign reaction can be confused with metastases of thoracic malignancies. We experienced three lung cancer cases with COVID-19 vaccine-related lymphadenopathy. Case presentations. Three patients were included. One was a pre-operative patient, and the others were post-operative patients. All of them were patients with lung cancer and had been vaccinated for COVID-19. They were found to have swelling of the axial lymph nodes on computed tomography several days after undergoing vaccination for COVID-19. Two patients underwent an axial lymph node biopsy. The results of biopsies and close follow-up revealed that none of them actually had metastasis. Conclusions. Invasive examinations should be avoided, but inappropriate upstaging and downstaging may result in miserable outcomes. We herein report three cases with imaging and pathological characteristics.

Background. Immune checkpoint inhibitors (ICI) have contributed to major improvements in the antineoplastic treatment of non-small-cell lung cancer. However, studies have reported different patterns of response to programmed cell death protein 1 (PD-1) blockade among individual tumors. Case. A 66-year-old man was diagnosed with squamous cell carcinoma in the bilateral upper lobes (simultaneous multiple lung cancer). He underwent combination therapy consisting of ICI treatment and platinum-based chemotherapy (pembrolizumab+carboplatin+nab-paclitaxel). After four courses of therapy, computed tomography revealed a response in the bilateral tumors. After 23 courses of maintenance treatment with pembrolizumab, the tumor in the left upper lung remained undetectable, while that in the right upper lung had decreased in size. However, the right mediastinal lymph node (#4R) had increased in size. Images obtained via [¹⁸F] -fluorodeoxyglucose positron emission tomography/computed tomography revealed the accumulation of fluorodeoxyglucose at the same site, which we then diagnosed as mediastinal lymph node metastasis. Although the right hilar tumor remained, there was no obvious increase in size. Therefore, mediastinal lymph node resection was performed to control the disease and perform analyses for genetic mutations. Maintenance therapy with pembrolizumab was continued following the procedure. The patient's condition remains stable without exacerbation 1 year and 11 months after the diagnosis (4 months after surgery). Conclusion. The progression pattern as a response to PD-1 blockade across individual metastases in non-small-cell lung cancer is heterogeneous in some cases. For patients exhibiting local progression, surgical resection may aid in controlling the disease.

Background. Lung cancer often metastasizes to the bone. Bone metastasis is diagnosed and evaluated by bone scintigraphy and treated with bone modifying agents. Since bone modifying agents may cause osteonecrosis of the jaw (ONJ) as a serious adverse event, their use requires caution. Case 1. A 72-year-old man with multiple bone metastases from adenocarcinoma of the lung, treated with pemetrexed and zoledronic acid. Case 2. A 62-year-old woman with postoperative recurrence of lung adenocarcinoma with multiple bone metastases, treated with osimertinib and denosumab. Case 3. A 73-year-old man with multiple bone metastases from adenocarcinoma of the lung, treated with osimertinib and denosumab. These three patients with lung cancer accompanied by multiple bone metastases developed ONJ while undergoing chemotherapy and treatment with bone-modifying agents. In all three patients, the bone scintigraphy obtained during follow-up showed the uptake of ^99mTc in the mandible before the onset of ONJ symptoms. Conclusion. When bone scintigraphy is performed for early detection and treatment of ONJ during treatment with bone modifying agents, the mandible should also receive focus. Medical and dental cooperation should be promoted. If the uptake is detected, early consultation with a dentist should be performed.

Background. When a fungus ball-like nodule is found inside a cavitary lesion, simple pulmonary aspergilloma is one of the most important differential diagnoses to consider. Case. A 58-year-old man who was suffering from cough, dyspnea, and bloody sputum that had persisted for more than one month was referred to our hospital. Chest CT showed a 4.5 cm cavitary lung lesion and an internal 1.2 cm nodule in the right S⁶ area. The peripheral side of the cavity showed consolidation, and antimicrobial therapy was started. After four months, the consolidation improved, however, the cavity in the right S⁶ grew to 5.0 cm and showed thickening of the cavity wall. The round nodule inside the cavity also increased from 1.2 cm to 4.0 cm. A fungus-ball due to simple pulmonary aspergilloma was suspected. Surgical resection was performed for symptom control. The pathological diagnosis was lung adenocarcinoma. Conclusion. Although primary lung cancer presenting with a fungus ball-like shadow is rare, cases have been reported. The possibility of primary lung cancer should be taken into consideration when a patient presents with mycosis fungoides that does not respond to antifungal agents.

Background. Lung cancer metastasis to the epipharynx is extremely rare. Case. Right cervical lymphadenopathy appeared after six courses of chemotherapy with cisplatin, pemetrexed, and bevacizumab and ten courses of maintenance therapy with pemetrexed and bevacizumab for right lung adenocarcinoma (pT2aNxM1a; stage IVA). Contrast enhanced computed tomography showed cervical lymphadenopathy, and nasopharyngeal fiberscopy showed an uplifting lesion in the epipharynx. Consequently, a biopsy during nasopharyngeal fiberscopy was performed, leading to a diagnosis of lung adenocarcinoma with epipharyngeal metastasis. Radiation therapy improved the symptoms. Conclusion. When neck swelling or nasopharyngeal symptoms are observed in lung cancer patients, it is considered that an appropriate treatment selection can be made by carefully examining the presence of lung cancer metastasis and head and neck cancer.

Background. The efficacy of local consolidative therapy (LCT) for oligometastatic non-small-cell lung cancer (NSCLC) has been reported. However, the feasibility and prognostic impact of LCT following immunotherapy have been unknown. We herein report a patient who underwent immunotherapy followed by LCT for oligometastatic NSCLC. Case. A 66-year-old male former smoker presented with stage IV lung cancer in the right upper lobe and an oligometastasis in the right adrenal gland. The patient underwent chemoimmunotherapy, which resulted in a partial response. Right upper lobectomy with mediastinal lymph node dissection followed by stereotactic body radiotherapy (SBRT) with a CyberKnife for a right adrenal metastasis was planned as LCT. The surgery was provided 86 days after the chemoimmunotherapy due to the requirement of steroid therapy for arthritis as an immune-related adverse event (irAE). SBRT with a CyberKnife was conducted 58 days after the surgery. He has been alive without disease relapse for one year since the initiation of treatment. Conclusion. In general, there are multiple treatment choices, combinations, and orders for LCT; therefore, accumulating individual case experiences and sharing information on the outcomes is crucial. SBRT with a CyberKnife is one choice for LCT for oligometastasis of the adrenal gland. Care should be taken to complete surgery as LCT in patients with irAEs requiring steroid therapy.

Background. Bronchopulmonary typical carcinoid tumors with distant metastasis and carcinoid syndrome are rare. Case. We report the case of a 77-year-old woman diagnosed with a bronchial typical carcinoid in the right middle lobe bronchus and multiple liver metastases. The patient presented with facial flushing and diarrhea, and the serotonin blood levels were elevated, indicative of carcinoid syndrome. Combination therapy with everolimus and octreotide maintained the patient in a healthy condition for approximately two years until she died in 2019. Conclusion. Bronchial typical carcinoids with multiple liver metastases and carcinoid syndrome in our patient was well-managed by combination therapy with everolimus and long-acting release octreotide.