Liposarcoma of soft tissue can occur in specific locations such as the pancreas, oral cavity, limbs, and abdominal cavity, presenting challenges in clinical diagnosis and treatment [4–5]. DDLPS often lacks typical clinical manifestations in the early stages, leading to delayed treatment and tumor spread. In this case, a female patient presented with a tumor in the abdominal and pelvic regions. Due to the unknown origin of the tumor, preoperative characterization and localization were crucial. Detailed inquiry into the patient's medical history revealed rapid growth of an abdominal mass, accompanied by respiratory distress and difficulty in eating. A thorough physical examination was performed to assess the relationship between the lesion and surrounding tissues and the presence of adhesions. Preoperative enhanced MRI and ultrasound examinations indicated a sizeable intra-abdominal mass causing compression of surrounding organs, elevated intra-abdominal pressure, and an undetermined nature of the lesion. Additionally, female tumor markers were evaluated, showing elevated carbohydrate antigen 125 (CA125) levels at 189.80 U/ml and neuron-specific enolase (NSE) at 22.77 ng/ml. These elevated markers preliminarily suggested an invasive or malignant process rather than a benign condition, providing valuable information for the diagnosing malignancy and preoperative surgical planning [6].
The abdominal cavity, a closed space with limited expandability, posed challenges in this case where the tumor volume was large and compressing surrounding tissues, affecting the patient's circulation, respiration, and potentially leading to the development of abdominal compartment syndrome (ACS) [7]. ACS can harm multiple systems, including reproductive, respiratory, circulatory, and urinary systems, leading to multiple organ dysfunction syndrome (MODS) and jeopardizing the patient's life [8]. Prolonged compression of the abdominal cavity by the tumor resulted in increased intra-abdominal pressure. Consequently, a slow and cautious tumor dissection process was essential during surgery to prevent a rapid decrease of negative pressure, altering the local microenvironment and causing cardiac and pulmonary function decompensation. Furthermore, DDLPS exhibits a high degree of malignancy and a higher recurrence rate. During tumor dissection, efforts were made to achieve negative margins to reduce the risk of postoperative recurrence.
Treatment options for DDLPS include complete surgical resection, radiation therapy, and chemotherapy. Treatment strategies may vary considering the anatomical and biological subtypes of the tumor. Complete surgical resection remains the cornerstone of DDLPS treatment, given its broad spectrum of genetic profiles, complex tumor microenvironment, and aggressive biological behavior [9–10]. With advancements in medical technology, treatment approaches have become more diverse. Sensitivity to adjuvant chemotherapy varies depending on the morphological and pathological characteristics of the tumor. Kollár et al. [11] conducted preoperative radiotherapy for liposarcoma with a total dose of 50.0-50.6 Gy, divided into 25–28 fractions of 1.8-2.0 Gy each, completed within 5–6 weeks. This approach could improve local disease control but presents acute and chronic toxicity concerns. With the development of molecular biology and molecular genetics, molecular and genetic testing provides new treatment directions for targeted gene-based diagnosis and treatment in clinical practice [12]. In the present case, immunophenotyping and fluorescence in situ hybridization (FISH) testing revealed S100 (+), MDM2 (scattered +), CDK4 (diffuse +), P16 (diffuse +), Desmin (+), and Ki-67 (20%+). Targeted therapies directed at genes such as MDM2 and CDK4 have progressed in treating liposarcoma. MDM2 and CDK4 co-amplification on 12q13–15 may serve as initiating factors for well-differentiated liposarcoma WDLPS and DDLPS, with DDLPS exhibiting a more complex genetic profile and greater invasiveness than WDLPS [13]. MDM2 amplification leads to ubiquitination and apoptosis of p53, acting as a negative regulatory factor for the p53 tumor suppressor. Therefore, MDM2 antagonists have been gradually developed in clinical practice. SAR405838 stabilizes p53 and activates the pathway, reducing cell proliferation, inducing cell cycle arrest, and promoting apoptosis in liposarcoma, lymphoma, and leukemia [14]. CDK4 amplification results in the overexpression of CDK4 protein, leading to Rb phosphorylation and accelerating the cell cycle process. CDK4 is a critical regulatory factor in the G1/S cell cycle checkpoint, and it co-enriches with MDM2 in over 90% of patients. Palbociclib and Abemaciclib, selective inhibitors of CDK4, have shown promising results in clinical trials, and ongoing and future studies will contribute to validating these drugs [15–16]. Abdul Razak et al. [17] conducted a phase lb clinical trial using MDM2 inhibitor Siremadlin and CDK4 inhibitor Ribociclib in combination therapy for liposarcoma. The recommended doses were Siremadlin 120 mg every 3 weeks plus Ribociclib 200 mg daily. This combination achieved controllable toxicity and early anti-tumor activity in WDLPS and DDLPS.
Postoperatively, the massive abdominal mass was successfully removed, reducing intra-abdominal pressure. The patient was advised to engage in early mobilization, promoting intestinal motility and preventing deep vein thrombosis in the lower extremities. Regular follow-up visits were scheduled, and the patient recovered well.