{
  "abstract": "Mucinous neoplasms of the lung are difficult to differentiate from upper gastrointestinal neoplasms based on pathologic appearance and immunohistochemistry (IHC) alone. Both variably express cytokeratin 7 (CK7), cytokeratin 20 (CK20), and caudal type homeobox 2 (CDX2), while often lacking thyroid transcription factor 1 (TTF-1) and Napsin-A. This case presents a patient with a history of a resected pancreatic intraductal papillary mucinous neoplasm (IPMN) who was found to have a large mucinous neoplasm in the left lung seven years later. Following resection for presumed primary pulmonary invasive mucinous adenocarcinoma, new metastatic lung lesions developed. Comparative morphologic evaluation of the resected lung lesion and the IPMN noted similarities. Subsequent next-generation sequencing from both samples identified the same ETV6::NTRK3 fusion. The patient started systemic therapy with larotrectinib, which led to clinical improvement and resolution of all lung lesions with response ongoing at the time of publication. IPMNs are premalignant lesions with the potential to transform into invasive malignancies and subsequently metastasize. NTRK fusions, while rare, occur across the spectrum of epithelial neoplasms, including IPMNs. In this case thorough molecular testing of both the active pulmonary malignancy and the antecedent pancreatic premalignancy identified the likely etiology of the mucinous adenocarcinoma and allowed for treatment with effective oral therapy.",
  "abstract_shown": true,
  "affiliations": [
    "Clinical Research Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.",
    "Division of Hematology & Oncology, Department of Medicine, University of Washington, Seattle, WA, USA.",
    "Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA."
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Nicholas P Giustini",
      "orcid": "0000-0001-5974-7545"
    },
    {
      "affs": [
        2
      ],
      "name": "Eric Q Konnick",
      "orcid": "0000-0001-5904-1788"
    },
    {
      "affs": [
        2
      ],
      "name": "Troy Hutchens",
      "orcid": "0009-0009-0621-1769"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Keith D Eaton",
      "orcid": "0000-0001-5025-2001"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2n603nn3cp94n.bib",
  "cited_by": 0,
  "doi": "10.21037/jgo-2026-0684",
  "fulltext_url": "https://europepmc.org/articles/PMC13740580",
  "id": "2n603nn3cp94n",
  "issns": [
    "2078-6891",
    "2219-679X"
  ],
  "landing_url": "https://europepmc.org/article/MED/42996621",
  "language": "eng",
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2740|Metastasis and carcinoma case studies"
    ]
  ],
  "openalex": "W7223907798",
  "pdf_url": "https://europepmc.org/articles/PMC13740580?pdf=render",
  "pmcid": "PMC13740580",
  "pmid": "42996621",
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2n603nn3cp94n.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T15:20:41Z",
      "native_id": "MED:42996621",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42996621"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "journal-openalex:2730|Gastric Cancer Management and Outcomes",
      "subfield": "oncology"
    }
  ],
  "title": "Metastatic pulmonary ETV6::NTRK3 mucinous adenocarcinoma originating from an intraductal papillary mucinous neoplasm case report.",
  "title_text": "Metastatic pulmonary ETV6::NTRK3 mucinous adenocarcinoma originating from an intraductal papillary mucinous neoplasm case report.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T15:20:41Z",
  "url": "https://research.draconitic.com/paper/2n603nn3cp94n",
  "venue": "Journal of gastrointestinal oncology",
  "versions": []
}