Mesenchymal tumors of the lungs are rare, mostly aggressive, with a high metastatic rate, representing only 0.013-1.1% of all pulmonary malignancies. Primary pulmonary myxoid sarcoma is an extremely rare type of lung sarcoma and stands as a separate entity in the 2015 WHO classification, characterized by EWSR1-CREB fusion gene. So far, 37 myxoid sarcoma cases have been reported. We offer an overview of the most important characteristics of pulmonary myxoid sarcoma and differential diagnosis, while reviewing the reported cases. We present the case of a 47-year-old patient with pulmonary myxoid sarcoma, who was diagnosed with a right central pulmonary mass, showing rapid endobronchial progression, complicated by empyema. EWSR1 gene translocation could not be detected. During chemotherapy, tumor progression occurred. Molecular genetic examinations revealed MET gene exon 14 skipping mutation, based on which tyrosine-kinase inhibitor treatment was administered. Pulmonary myxoid sarcoma can be classified as a nonvascular, spindle cell entity of mesenchymal tumors, with the characteristic EWSR1-CREB1 gene translocation. The male-female ratio is similar, with a slightly higher incidence in middle-aged women (1.5 : 1). Patients\' average age is 44 years; with predilection in the right upper lobe (62%), or endobronchially (85%). Without specific symptoms, diagnosis is often cumbersome. Immunohistochemical methods, typical hystological image and molecular genetic tests confirm the diagnosis. Pulmonary myxoid sarcoma is a rare entity, without specific symptoms. In our case, myxoid sarcoma was complicated by empyema, which was drained. Because of advanced stage, surgical resection was not an option. Radical surgery offers the best results, in inoperable cases therapeutic recommendations for sarcomas are the guiding principles. Our case belongs to the rare group of myxoid sarcomas, where MET activating mutation was detected, making it eligible for targeted treatment. Orv Hetil. 2023; 164(27): 1077-1083.
A tüdőből kiinduló rosszindulatú mesenchymalis daganatok ritkák, többnyire agresszív, áttétet képző tumorok, melyek az összes rosszindulatú tüdődaganatnak csak a 0,013–1,1%-át teszik ki. Az Egészségügyi Világszervezet 2015. évi beosztásában külön entitásként szereplő primer myxoid tüdősarcoma egy még ritkábban előforduló tüdősarcoma-típus: a legtöbb esetben ismétlődő kiegyensúlyozott kromoszomális transzlokáció jellemzi, amely az EWSR1–CREB1 fúziós génhez vezet. Eddig 37, myxoid tüdősarcomás esetet közöltek az irodalomban. Esetünk kapcsán áttekintjük a primer myxoid tüdősarcoma fontosabb jellemzőit és differenciáldiagnosztikáját, valamint áttekintést adunk az irodalomban eddig talált myxoid tüdősarcomás betegekről. Egy 47 éves, primer myxoid tüdősarcomás beteg esetét mutatjuk be, akinél rapid endobronchialis progressziót mutató, jobb oldali centrális tüdőtumor igazolódott, mely empyemával szövődött. Az EWSR1-gén transzlokációját betegünknél nem lehetett kimutatni. A kemoterápiás kezelés mellett, átmeneti egyensúlyi állapotot követően, tumorprogresszió alakult ki. A molekuláris genetikai vizsgálat során a MET-gén 14. exonjának ’skipping’ mutációját igazoltuk, amelyre célzott tirozin-kináz-gátló kezelés indult. A primer myxoid tüdősarcoma a mesenchymalis tumorok nonvascularis, orsósejtes tumorai közé sorolható, a jellegzetes EWSR1–CREB1 fúziós gén transzlokációjával. A férfi-nő arány közel egyező, középkorú nők körében némileg gyakoribb előfordulású (1,5 : 1). Az átlagéletkor 44 (23–80) év. Általában jobb felső lebenyi (62%), illetve endobronchialis (85%) elhelyezkedésű. Specifikus tünettan hiányában a diagnózis nem könnyű. Immunhisztokémiai módszerek, a jellegzetes szöveti kép, illetve a molekuláris genetikai vizsgálat erősítheti meg a diagnózist. A primer myxoid tüdősarcoma ritka entitás, specifikus tünetek nélkül. Betegünknél a myxoid tüdősarcoma empyemával szövődött, mely miatt mellűri drenázs történt. Az előrehaladott stádium miatt reszekcióra nem került sor. Pulmonalis sarcomákban a legjobb eredményeket radikális műtéti eltávolítással lehet elérni, inoperábilis esetekben a sarcomákra vonatkozó terápiás ajánlások irányadóak. Esetünk a myxoid tüdősarcomák azon ritka csoportjába tartozik, amelynél célzott kezelésre alkalmas MET-aktiváló mutációt lehetett kimutatni. Orv Hetil. 2023; 164(27): 1077–1083.

UNASSIGNED: This plain language summary provides an overview of two of the main clinical studies that led to tepotinib\'s approval, the phase I first-in-human study and the phase II VISION study.
UNASSIGNED: Tepotinib is a targeted anti-cancer treatment taken orally (by mouth). It is available in many countries for people with advanced or metastatic non-small cell lung cancer (NSCLC), where the tumor contains a genetic mutation (alteration) called \'MET exon 14 skipping\'. Tumor cells rely on this mutation to grow and survive, so targeted blocking of the effect of this mutation is an important treatment approach. MET exon 14 skipping occurs in approximately 3-4% of people with NSCLC. These people are usually of older age. This subtype of NSCLC is associated with poor outcomes. Before treatments that specifically target this MET mutation were developed, only general treatments such as chemotherapy were available for this type of cancer. Because chemotherapy attacks all rapidly dividing cells in a person\'s body and is administered intravenously (through a vein), it can often cause unwanted side effects. Cancer cells grow and divide rapidly because of defects, often involving proteins called \'tyrosine kinases\'. Specific tyrosine kinase inhibitors (TKIs) were therefore developed to slow or stop cancer growth by targeting these proteins. Tepotinib is a MET TKI. This means that it blocks the activity of the MET pathway that is overactive in MET exon 14 skipping NSCLC. Doing this, may slow down cancer growth.
UNASSIGNED: In the studies summarized here, people with MET exon 14 skipping NSCLC who took tepotinib had their tumor growth stopped or their tumor shrunk for a period of time, and they mostly experienced side effects that they could tolerate. Clinical Trial Registration: NCT01014936 (tepotinib first-in-human), NCT02864992 (VISION), NCT03940703 (INSIGHT 2) (ClinicalTrials.gov).

BACKGROUND: Fusions of the anaplastic lymphoma receptor tyrosine kinase gene (ALK), ret proto-oncogene (RET), ROS proto-oncogene 1, receptor tyrosine kinase gene (ROS1), B-Raf proto-oncogene, serine/threonine kinase gene (BRAF), and neuregulin 1 gene (NRG1) and intronic MMNG HOS Transforming gene (MET) mutations are druggable oncogene alterations in lung adenocarcinoma that cause expression of aberrant transcripts. Because these aberrant transcripts are both infrequent (incidence <5%) and mutually exclusive, multiplex assays are required to detect them in tumor samples.
METHODS: Aberrant transcripts of the six aforementioned oncogenes (36 transcripts in total) were examined in a molecular counting (MC) assay, which counts RNA molecules by simultaneous hybridization of several probes. Forty-one samples of surgically resected lung adenocarcinoma tissue found to express one of these aberrant oncogenic transcripts upon whole transcriptome sequencing (test cohort: n = 22) or reverse transcription polymerase chain reaction (validation cohort: n = 19) analyses were subjected to MC, after which biopsies were performed on tumor tissue samples.
RESULTS: Threshold values for the diagnosis of each of the 36 transcripts were determined in frozen and formalin-fixed paraffin-embedded samples from the test cohort. On the basis of these threshold values, the MC assay diagnosed expression of oncogenic transcripts in the validation cohort samples with 100% accuracy. The assay also accurately detected oncogenic fusions in bronchial lavage fluid and transbronchial biopsy samples.
CONCLUSIONS: The MC assay allows multiplex detection of oncogenic fusion and exon-skipped transcripts in tumor samples, including in formalin-fixed paraffin-embedded samples obtained in the clinic.