A component of high‐grade fetal lung adenocarcinoma diagnosed as the cause of lymph node metastasis

• Published in: Thoracic cancer Vol. 15; no. 13; pp. 1112 - 1116
• Main Authors: Ishii, Daichi, Aoyama, Satoshi, Arai, Wataru, Hasegawa, Masaru, Tanaka, Akihiko, Sakuraba, Motoki
• Format: Journal Article
• Language: English
• Published: Melbourne John Wiley & Sons Australia, Ltd 01.05.2024; John Wiley & Sons, Inc; Wiley
• Subjects: Adenocarcinoma of Lung - pathology; Adenocarcinoma of Lung - surgery; Aged; Antigens; Case Report; Case Reports; Conflicts of interest; Health risks; high‐grade fetal lung adenocarcinoma; Humans; Lung cancer; Lung Neoplasms - pathology; Lung Neoplasms - surgery; lymph node metastasis; Lymph Nodes - pathology; Lymphatic Metastasis; Lymphatic system; Male; Medical diagnosis; Metastasis; Morphology; Neoplasm Grading; Patients; Proteins; Stains & staining; Thyroid gland; thyroid transcription factor‐1; Tomography; Transcription factors; lung cancer; high‐grade fetal lung adenocarcinoma; thyroid transcription factor‐1; lymph node metastasis
• ISSN: 1759-7706; 1759-7714
• DOI: 10.1111/1759-7714.15296

High‐grade fetal lung adenocarcinoma (H‐FLAC) is a rare type of tumor. There have been no reports demonstrating the degree of metastatic susceptibility of this tumor type. In this report, we describe a case in which 15% of the adenocarcinoma components were H‐FLAC diagnosed as the cause of lymph node metastasis. A 75‐year‐old man presented with suspected primary lung cancer (clinical stage IIA, T2bN0M0) and underwent left upper lobectomy and superior mediastinal lymph node dissection. Postoperative histopathology revealed lung cancer with only lobar bronchial lymph node (#11) metastasis. Approximately 60% of the invasive adenocarcinoma showed a papillary morphology, 25% showed a lepidic morphology, and 15% showed a fetal morphology. The histomorphological and immunohistological features of #11 metastasis were similar to those of H‐FLAC. Herein, we report a rare and important case of H‐FLAC with proven lymph node metastasis, showing that even a small amount of H‐FLAC tissue can cause metastasis. This is the first report to demonstrate the histological characteristics of high‐grade fetal lung adenocarcinoma (H‐FLAC) as the cause of N1 in a patient with lung adenocarcinoma containing a small number of H‐FLAC components.