The tumor microenvironment (TME) plays a fundamental role in tumorigenesis, tumor progression, and anti-cancer immunity potential of emerging cancer therapeutics. Understanding inter-patient TME heterogeneity, however, remains a challenge to efficient drug development. This article applies recent advances in machine learning (ML) for survival analysis to a retrospective study of NSCLC patients who received definitive surgical resection and immune pathology following surgery. ML methods are compared for their effectiveness in identifying prognostic subtypes. Six survival models, including Cox regression and five survival machine learning methods, were calibrated and applied to predict survival for NSCLC patients based on PD-L1 expression, CD3 expression, and ten baseline patient characteristics. Prognostic subregions of the biomarker space are delineated for each method using synthetic patient data augmentation and compared between models for overall survival concordance. A total of 423 NSCLC patients (46% female; median age [inter quantile range]: 67 [60-73]) treated with definite surgical resection were included in the study. And 219 (52%) patients experienced events during the observation period consisting of a maximum follow-up of 10 years and median follow up 78 months. The random survival forest (RSF) achieved the highest predictive accuracy, with a C-index of 0.84. The resultant biomarker subtypes demonstrate that patients with high PD-L1 expression combined with low CD3 counts experience higher risk of death within five-years of surgical resection.

Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a recently described rare and aggressive malignancy characterized by undifferentiated cell morphology and the loss of the Brahma-related gene 1 (BRG1) protein. Its pathogenesis involves mutational loss of SMARCA4 gene expression, which encodes the BRG1 protein that serves as one of the catalytic subunits of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex. This malignancy of the thorax predominantly affects middle-aged male smokers and commonly metastasizes to lymph nodes, bones, adrenal glands, liver, gastrointestinal tract, central nervous system, and kidney. Cases of brain metastasis have been reported but are less common. We report a case of this tumor initially presenting with diffuse brain metastasis in a 55-year-old male with a significant smoking history. We reviewed the current literature on the diagnostic and therapeutic challenges posed by this highly aggressive thoracic tumor.

Airway compression resulting from thoracic tumors requires evaluation of the possibility of fatal ventilation failure when securing the airway. A woman presenting with a thoracic mass on the right side causing airway compression at the level of tracheal bifurcation required tumor removal to alleviate the compression; however, securing the airway proved challenging. Furthermore, differential lung ventilation was necessary for surgical management. We planned to secure the airway and manage breathing with the assistance of veno-arterial extracorporeal membrane oxygenation (V-A ECMO) through an interdisciplinary conference and proceeded according to the plan. The intended tracheal tube could be placed, differential lung ventilation was initiated, and the ECMO was removed. The surgical procedure was carried out. In patients presenting with airway stenosis, the possibility of difficulty in securing the airway and ventilation should be assessed in advance. Creating a detailed treatment plan before surgery is recommended.

Ganglioneuroma, a rare benign neuroblastic tumor, typically arises in the posterior mediastinum, but it can be found in the anterior mediastinum and thymus. Predominantly affecting the young, these asymptomatic tumors are often discovered incidentally through imaging. In our reported case, a 44-year-old woman post-hysterectomy with persistent jaundice was diagnosed with a neuroganglioma in the right posterior mediastinum via a computed tomography (CT) scan. Thoracotomy and resection revealed a 10-cm neuroganglioma untangled from mediastinal planes. Post-surgery, chylothorax emerged, which was managed through a 5-day fasting approach. Thoracic neurogangliomas, rare and often asymptomatic, demand meticulous diagnosis, emphasizing imaging and histopathology, with postoperative vigilance for complications.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary tumor syndrome characterized by endocrine tumors with mainly a parathyroid, pancreatic, or anterior pituitary origin. Low-grade fibromyxoid sarcoma (LGFMS) is a rare low-grade soft tissue tumor. There is one known report of a patient with MEN1 complicated by LGFMS, which is very rare. Our report represents the second documented case, providing valuable insights.
METHODS: A 31-year-old man with the chief complaint of a cough underwent chest contrast-enhanced computed tomography, which revealed a giant hypoabsorptive tumor with a maximum diameter of 23 cm in the left thoracic cavity. The patient was diagnosed with MEN1, as he also possessed a pancreatic neuroendocrine tumor and parathyroid tumor, and because his father had been found to have MEN1. To control hypercalcemia, surgery for the parathyroid tumor was initially performed, followed by surgical resection of the giant thoracic tumor for diagnosis and treatment. Histopathological examination findings of the tumor resulted in a diagnosis of LGFMS.
CONCLUSIONS: We experienced a very rare MEN1 with LGFMS. Although endocrine tumors generally occur more frequently in MEN1, non-endocrine tumors such as the present case should also be noted, reinforcing the importance of systemic imaging scrutiny in addition to early diagnosis and long-term follow-up of MEN1 patients.

BACKGROUND: Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a recently described aggressive neoplasm of young smokers defined by SMARCA4 inactivating mutations and characterized by cells with rhabdoid morphology, high mitotic activity, and abundant necrosis.
OBJECTIVE: Describe and compare 3 unusual presentations of SMARCA4-UT in older adults, including one presenting as a metastatic lesion mimicking a primary bone sarcoma. Discuss the molecular characteristics of SMARCA4-UT and their relationship to nonsmall-cell lung carcinomas with SMARCA4.
METHODS: Three patients with SMARCA4-UTs were identified utilizing a natural language search in CoPath. hematoxylin and eosin sections from all patients as well as Papanicolaou-stained slides and Diff-Quik-stained slides for the first patient were examined. A broad range of immunostains, including BRG1/SMARCA4, were evaluated. Molecular testing was performed via next-generation sequencing.
RESULTS: The 3 patients were aged 58, 70, and 70 years. All had a significant smoking history. The first patient presented with an iliac bone mass and mediastinal lymphadenopathy, the second with mediastinal adenopathy, and the third with a paratracheal mass. All 3 tumors showed a diffuse proliferation of pleomorphic, rhabdoid cells with high mitotic activity and tumor necrosis. SMARCA4 was lost in all 3 tumors by immunohistochemistry. Molecular testing revealed SMARCA4 alterations in the first 2.
CONCLUSIONS: Thoracic SMARCA4-UT should be considered in the differential diagnosis of pleomorphic rhabdoid tumors in older adults with a smoking history. Although most present as lung and/or mediastinal masses, they may occasionally present as a metastasis and mimic an undifferentiated sarcoma, representing a potential diagnostic pitfall.

A spinal epidural angiolipoma is a rare, benign tumor of adipocytes and blood vessels that accounts only for a small percentage of all spinal axis tumors. We report a case of a 44-year-old male who presented with three months of progressive decreased sensation and strength from about six cm above the umbilicus down to his feet bilaterally. He presented to the emergency room when he could no longer walk. He also had neurogenic urinary retention and likely neurogenic constipation. Physical exam was notable for decreased sensation, decreased strength, and increased patellar reflexes bilaterally. MRI of the thoracic spine showed a posterior epidural mass that spanned from T2 to T3, measuring 1.2 x 1.7 x 4.3 cm, and severely compressed the spinal cord posteriorly. The patient underwent an urgent laminectomy for decompression and mass resection. Pathology was consistent with an angiolipoma. Postoperatively, he experienced a drastic improvement in strength and gross motor skills. The sensation had a partial return following surgery and continued to improve over the hospital stay. In general, the literature reports significant symptomatic improvement in patients with spinal epidural angiolipomas after surgical resection.

Pseudoprogression is rarely mentioned after radiotherapy except for central nervous system tumors. With the widespread of immunotherapy, the incidence of pseudoprogression of thoracic tumor after radiotherapy is increasing. This study summarized the clinical features of pseudoprogression in 4 patients who had underwent thoracic radiotherapy after and/or followed by immunotherapy. All of them had received chemotherapy and immunotherapy before thoracic radiotherapy. After radiotherapy, pseudoprogression occurred within 3 months after initiation of immune consolidation/rechallenge therapy. At least a 20% increase in the sum of the longest diameter of target lesions were measured on their chest image. During this period, patients\' ECOG PS scores remained stable, specific serum tumor markers did not increase significantly. Treatment strategies did not change after pseudoprogression. The causes of radiographic pseudoprogression in this case series may be attributed to disturbances such as pneumonitis, atelectasis, mucus blockages and infection. In the era of immunotherapy, pseudoprogression of thoracic tumors after chest radiotherapy might become a common phenomenon. It is important for us to identify pseudoprogression based on patient\'s general status, radiological changes, and laboratory tests.

Mature fetiform teratoma, or homunculus, is a term coined for a rare variant of teratoma with a prevalence of 0.01% of teratomas. There have been very few cases reported in the world, and its thoracic presentation is extremely unusual. We present the case of a 31-year-old female patient with a history of progressive chest pain in the left hemithorax, associated with dyspnea on moderate exertion and cough. Imaging studies revealed a large intrathoracic tumor visually compatible with a teratoma. Surgical resection by a clamshell approach was successful, and subsequent anatomopathological studies of the operative specimen concluded that the mass was a mature fetiform thoracic teratoma. The treatment of this entity is generally surgical and includes wide resection due to its large adhesive component to surrounding tissues. Thus, the cardiothoracic surgeon must know approaches that allow wide resection, making these cases true surgical challenges.

BACKGROUND: Thymic lipofibroadenomas are extremely rare. In this study, we investigated the clinicopathological characteristics of thymic lipofibroadenomas.
METHODS: This study included three patients with thymic lipofibroadenomas. We retrospectively analyzed the patient data to determine the clinicopathological characteristics of thymic lipofibroadenomas. The study included one man and two women [mean age, 43 (33-59) years]. All patients were non-smokers and presented with well-defined anterior mediastinal tumors. The cut surfaces of the tumors were solid, with a mixture of yellow and white areas. Microscopic evaluation of resected specimens showed scattered cord-like structures of epithelial cells embedded within abundant fibrotic and hyaline stroma admixed with variable quantities of adipose tissue. One patient showed hyperplastic thymic tissue in a part of the tumor.
CONCLUSIONS: Thymic lipofibroadenomas are an extremely rare type of benign thymic tumor. Surgical removal of lipofibroadenomas is usually curative.