Recurrent Intrathoracic Liposarcoma: A Case Report and a Comprehensive Literature Review of a Rare Clinical Entity

Abstract

Liposarcomas (LPSs) are rare malignant tumors of adipocytic origin, primarily occurring in the extremities and retroperitoneum, with thoracic involvement being exceptionally rare. This case report details the surgical management and outcomes of a recurrent intrathoracic LPS in a 65-year-old male with a history of previous mediastinal tumor resection. CT imaging revealed a recurrent tumor extending into the left pleura. The patient underwent a posterolateral thoracotomy for complete tumor excision and limited replacement of the descending aorta. Postoperative recovery was smooth, and histology confirmed dedifferentiated LPS (G2) with areas of highly differentiated LPS. LPSs encompass a heterogeneous group of tumors with various subtypes, including atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS), dedifferentiated liposarcoma (DDLPS), myxoid liposarcoma (MLPS), and pleomorphic liposarcoma (PLPS). Treatment primarily involves complete surgical resection, while the roles of radiotherapy and chemotherapy remain debated. Immunotherapy shows potential benefits, particularly for DDLPS patients expressing PD-L1. Prognosis varies significantly by subtype, with DDLPS and PLPS associated with poorer outcomes compared to MLPS and ALT/WDLPS. Long-term follow-up is crucial for managing LPSs due to their high recurrence rate. This case highlights the effectiveness of surgical intervention in recurrent intrathoracic LPSs and underlines the need for continued research into adjuvant therapies to improve patient outcomes.

Keywords: adjuvant therapy; dedifferentiated liposarcoma (ddlps); long-term follow-up; pleural liposarcoma; recurrent intrathoracic liposarcoma; surgical resection.

Figure 1. Computed tomography imaging demonstrating the liposarcoma (arrow) resected five years ago. (A) Coronal view showing the size and position of the original tumor within the thoracic cavity. (B) Transverse view highlighting the tumor's relationship to the surrounding anatomical structures. (C) Sagittal view providing a detailed perspective on the tumor's depth and its proximity to vital organs.

Figure 2. Computed tomography imaging demonstrating the recurrence of the liposarcoma (arrow) in the left pleural cavity. (A) Transverse view illustrating the extent of the recurrent tumor within the left pleural cavity. (B) Sagittal view showing the tumor's infiltration into adjacent structures. (C) Coronal view detailing the spread and impact of the recurrent tumor on the pleural cavity.

Figure 3. Chest X-rays at different stages of treatment. (A) Preoperative image displaying the recurrent tumor's impact on lung fields and mediastinal structures. (B) Immediate postoperative image indicating the successful resection and the initial postoperative state of the thoracic cavity. (C) Image at discharge showing the recovery progress and the state of the thoracic cavity post-treatment.

Figure 4. Intraoperative access to the tumor. (A) Identification of the tumor (arrow) in the left pleural cavity, illustrating its location and size relative to the pleura. (B) Resection of the tumor (arrow), demonstrating the surgical process and the extent of the excised tissue. (C) The descending aorta after local segmental replacement (arrow), showing the repair performed due to local infiltration by the tumor.

Figure 5. Segments of the resected tumor. Detailed view of the different sections of the tumor removed during surgery, highlighting the varied morphology and size of the excised segments.

Figure 6. Histological images of the resected liposarcoma. (A) Section of a highly differentiated liposarcoma with sclerotic areas, displaying varying sizes of fat cells. (B) Another section of a highly differentiated liposarcoma with sclerotic areas, highlighting an enlarged nucleus with hyperchromasia. (C) Typical lipoblast with a double nucleus and small fat vacuoles within the cytoplasm. (D) Details of the dedifferentiated part of the liposarcoma, showing pronounced nuclear polymorphism and nonrecognizable fat cells. Additionally, a small osteoid formation is evident, indicating osteosarcomatous differentiation.