Rapidly developing intrathoracic low‐grade fibromyxoid sarcoma: A case report

• Published in: Thoracic cancer 2023-08, Vol.14 (23), p.2314-2319
• Main Authors: Narukami, Eri, Anayama, Takashi, Yamamoto, Marino, Bunno, Yujiro, Miyazaki, Ryohei, Okada, Hironobu, Iguchi, Mitsuko
• Format: Article
• Language: English
• Subjects: Aged, 80 and over; Antigens; Biopsy; Case Report; Case Reports; Chemotherapy; chest wall tumor; Female; Fibrosarcoma - surgery; FUS gene translocation; Humans; In Situ Hybridization, Fluorescence; LGFMS; Lung cancer; Metastasis; Neoplasm Recurrence, Local - pathology; Ostomy; Pulmonary arteries; pulmonary invasion; Sarcoma; Soft Tissue Neoplasms; Thoracic surgery; Tomography; Tumors; Young Adult
• ISSN: 1759-7706; 1759-7714
• DOI: 10.1111/1759-7714.15020

Low‐grade fibromyxoid sarcoma (LGFMS) is a rare mesenchymal tumor that primarily arises in the limbs and trunk of young adults, and rarely in the thoracic cavity. An 84‐year‐old Japanese woman presented with a right intrathoracic mass which was 8 cm in size. CT‐guided needle biopsy did not provide a definitive diagnosis. Perioperatively, a mass was found in the right lower lobe of the lung and was suspected to have invaded the chest wall at the sixth–eighth ribs. A right lower lobectomy and combined chest wall resection were performed. Microscopic examination revealed that the tumor was a low‐grade spindle cell tumor originating from the pleura demonstrating focal invasion of the lung. The tumor exhibited positivity for MUC4, and FUS gene translocation was confirmed through fluorescence in situ hybridization. Unfortunately, 10 months postoperatively, tumor recurrence was noted as peritoneal dissemination, and the patient passed away 13 months postoperatively. Although LGFMS may be diagnosed histologically as a low‐grade tumor by needle biopsy, in this case, it was highly malignant. Postoperative long‐term regular medical follow‐up is recommended considering the highly malignant nature of the tumor and the high risk of local recurrence and pulmonary metastasis. Intrathoracic LGFMS is an extremely rare thoracic malignancy. An 84‐year‐old woman initially suspected of having right lower lobe lung cancer (A) underwent surgical resection (B). Further analysis through FISH showed FUS gene (D) translocations (E, F), leading to a diagnosis of LGFMS. Unfortunately, postoperative recurrence occurred as peritoneal disseminations, highlighting the aggressive nature of the disease.