Differentiated liposarcoma is a rare connective tissue malignancy in adults that mostly occurs in the extremities and retroperitoneum, with a tendency to aggressiveness and recurrence, and the ten-year survival rate of about 10%. Clinically, dedifferentiated liposarcoma of the pharynx has been reported to be rare abroad and only one case has been reported in China. Clinical symptoms are mainly foreign body sensation in the pharynx, which can be easily misdiagnosed as benign tumors. Pathological diagnosis is the main examination tool for this kind of disease, and immunohistochemistry and FISH test can help to differentiate it from other tumors. This article presents a case of a male patient with dedifferentiated liposarcoma of the hypopharynx, who had a foreign body sensation in the pharynx for more than 1 month, and underwent supported laryngoscopic pharyngeal lesion resection after completing the preoperative relevant examinations and postoperative radiation therapy, with postoperative pathology returned as dedifferentiated liposarcoma. The present postoperative follow-up was 12 months without recurrence. Therefore, accurate diagnosis and timely treatment are extremely important for the prognosis of this disease.
Humans ; Male ; Liposarcoma/diagnosis* ; Hypopharyngeal Neoplasms/diagnosis* ; Middle Aged ; Hypopharynx ; Adult

OBJECTIVE: To explore the clinical characteristics and genetic etiology of a patient with De-differentiated liposarcoma (DDLPS). METHODS: A 38-year-old female patient with DDLPS who had visited Hunan Provincial People's Hospital in January 2025 was selected as the study subject. A retrospective study method was adopted to collect the patient's clinical data, including current and past medical history, auxiliary examinations, pathological diagnosis, and results of genetic testing. This study was approved by the Ethics Committee of Hunan Provincial People's Hospital (Ethics No.: KY2025-150). RESULTS: The patient had presented with abdominal pain and abdominal mass. Imaging studies revealed ascites and space-occupying abdominal lesions. Postoperative pathological examination showed that the tumor was composed of spindle cells, and its morphology and immunohistochemistry had made it difficult to distinguish between DDLPS and leiomyosarcoma. High-throughput sequencing revealed characteristic molecular alterations of DDLPS, and fluorescence in situ hybridization confirmed MDM2 gene amplification, leading to a diagnosis of DDLPS. CONCLUSION The patient was diagnosed with DDLPS. Her clinical manifestations and pathological features were consistent with the characteristics of DDLPS. Molecular pathological testing played a crucial role in the diagnosis and provided a crucial reference for subsequent treatment.
Humans ; Female ; Adult ; Liposarcoma/diagnosis* ; Phenotype ; Proto-Oncogene Proteins c-mdm2/genetics*

Retroperitoneal liposarcoma is an uncommon tumor both in the pregnant and nonpregnant state. Its exact incidence is unknown because of its rarity. Due to its propensity for local recurrence, prognosis depends on histologic subtype and negative margins of resection. Surgery remains the mainstay of treatment, and timing is critical in terms of finding a surgically resectable lesion while balancing fetal risks. This report describes tumor recurrence in a pregnancy with a prior history of surgery for an atypical lipomatous tumor presenting as a retroperitoneal mass. After discussion with the multidisciplinary team, as well as with the patient’s consent, the plan was to defer surgery until 34 weeks, followed by scheduled tumor removal 2 weeks postpartum. She delivered abdominally to a baby girl with a good outcome. Histopathology showed dedifferentiated liposarcoma with a positive tumor margin. The patient has survived at 6-month follow-up and completed four cycles of chemotherapy with doxorubicin, ifosfamide, and mesna. However, surveillance imaging again showed tumor recurrence.
Liposarcoma

Humans ; Liposarcoma/surgery* ; Retroperitoneal Neoplasms/surgery* ; Neoplasm Recurrence, Local/surgery*

Humans ; Retroperitoneal Neoplasms ; Liposarcoma ; Calcium-Binding Proteins ; Mixed Function Oxygenases ; Membrane Proteins ; Muscle Proteins

Humans ; Rectum/surgery* ; Liposarcoma/surgery* ; Biomarkers, Tumor

OBJECTIVE: To investigate the value of using MDM2 amplification probe and DDIT3 dual-color, break-apart rearrangement probe fluorescence in situ hybridization (FISH) technique in the diagnosis of liposarcoma. METHODS: In the study, 62 cases of liposarcoma diagnosed in Peking University First Hospital from January 2015 to December 2019 were analysed for clinicopathological information. Of these 62 cases of liposarcoma, all were analysed for MDM2 amplification and 48 cases were analysed for DDIT3 rearrangement using a FISH technique. Our study aimed to evaluate the status of MDM2 and DDIT3 by FISH in liposarcoma and correlate it with diagnosis of different subtypes of liposarcoma. The subtypes of liposarcoma were classified according to the FISH results, combined with the relevant clinicopathological features. RESULTS: The patients aged 31-89 years (mean: 59 years) with a 1.75:1 male to female ratio. Histologically, there were 20 cases of atypical lipomatous tumour/well-differentiated liposarcoma (ALT/WDLPS), 26 cases of dedifferentiated liposarcoma (DDLPS), 13 myxoid liposarcoma (MLPS) and 3 pleomorphic liposarcoma (PLPS). Tumors with DDLPS (23/26) and WDLPS (8/20) were localized retroperitoneally, while both tumours of MLPS and PLPS were localized extra-retroperitoneally, and the difference of sites among the four subtypes of liposarcoma was statistically significant (P < 0.05). Histologically, varied mucoid matrix could be observed in the four subtypes of liposarcoma, and the difference was statistically significant (P < 0.05). MDM2 gene amplification was demonstrated in all cases of ALT/WDLPS and DDLPS (100%, 20/20 and 26/26 respectively); DDIT3 gene rearrangement was noted only in MLPS (100%, 13/13); most cases of DDLPS (96.2%, 25/26) and ALT/WDLPS (83.3%, 5/6, 6 cases selected for detection) demonstrated the picture of amplification of the DDIT3 telomeric tag. According to the instructions of DDIT3 break-apart rearrangement probe, the 5' telomere probe and 3' centromere probe spanned but did not cover the DDIT3 gene itself, on the contrary, the 5' telomere probe covered the CDK4 gene, while the DDIT3 and CDK4 gene were located adjacent to each other on chromosome, therefore, when the amplification signal appeared on the telomeric tag of the DDIT3 rearrangement probe, it indeed indicated the CDK4 gene amplification rather than the DDIT3 gene rearrangement. Then the 10 cases with DDIT3 telomeric tag amplification were selected for CDK4 and DDIT3 gene amplification probe FISH tests, and all the cases showed CDK4 gene amplification (100%, 10/10) and two of the 10 cases demonstrated co-amplification of CDK4 and DDIT3 (20%, 2/10); DDIT3 polysomy detected by DDIT3 gene rearrangement probe was found in 1 case of DDLPS and 2 cases of PLPS (66.7%, 2/3) with morphology of high-grade malignant tumour and poor prognosis. CONCLUSION Our results indicate that a diagnosis of different subtype liposarcoma could be confirmed based on the application of MDM2 and DDIT3 FISH, combined with clinicopathological findings. It is also noteworthy that atypical signals should be correctly interpreted to guide correct treatment of liposarcomas.
Male ; Female ; Humans ; In Situ Hybridization, Fluorescence/methods* ; Cyclin-Dependent Kinase 4/metabolism* ; Liposarcoma/pathology* ; Lipoma/pathology* ; Gene Amplification ; Transcription Factor CHOP/genetics* ; Proto-Oncogene Proteins c-mdm2/metabolism*

Objective: To investigate the clinicopathological features and differential diagnoses of paratesticular liposarcoma. Methods: The cases were collected from 2012-2020, from the archives of the Department of Pathology, Peking University Third Hospital, with diagnosis confirmed by histology, immunostaining and FISH tests. Results: Totally 19 patients were enrolled (including 11 in-hospital patients and 8 consultant cases). The patients aged 37-84 years (mean 57 years). The preoperative clinical diagnoses were spermatic cord/inguinal masses (nine patients), scrotal masses (seven patients), and inguinal hernia (three patients). Six lesions recurred after local resection, including one case extending from pelvic liposarcoma. Histologically, there were 10 cases of well-differentiated liposarcoma (WDLPS) and nine cases of dedifferentiated liposarcoma (DDLPS). WDLPSs mostly showed the combined features of lipoma-like, inflammatory and sclerosing subtypes (six patients); the other four WDLPSs had pure lipoma-like subtype features. DDLPSs were low-grade (three patients) or high-grade (six patients), with the morphology resembling myxofibrosarcoma, inflammatory myofibroblastoma, spindle cell sarcoma, pleomorphic undifferentiated sarcoma and pleomorphic liposarcoma. Intense inflammatory cells infiltration was commonly observed in five WDLPSs and two DDLPSs. Ossification was observed in three tumors. Immunohistochemically, the tumors were positive for MDM2 (8/10) and CDK4 (10/10), which were expressed in lipo-differentiating cells, spindle cells in WDLPS, and in dediffferentiated components. S-100 was only expressed by lipocytes (10/10). CD34 expression was positive and diffuse in the stromal cells of WDLPSs and focal or diffuse in dedifferentiated areas (10/10). FISH tests with an MDM2 gene probe were positive (12/12). Conclusions: Paratesticular liposarcoma may be overlooked by both clinicians and pathologists. WDLPS and DDLPS predominate, showing various histologic divergences. The presence of amplification of the 12q14-q15 region (containing the MDM2 and CDK4 genes) is helpful for making the correct diagnosis.
Adult ; Genital Neoplasms, Male/surgery* ; Humans ; In Situ Hybridization, Fluorescence ; Liposarcoma/surgery* ; Male ; Proto-Oncogene Proteins c-mdm2/genetics* ; Soft Tissue Neoplasms

Objective: To investigate the value of MDM2 RNA in situ hybridization (RNA-ISH) in diagnosing atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) and dedifferentiated liposarcoma (DDL). Methods: A total of 26 ALT/WDL/DDLs diagnosed from March 2017 to May 2019 in West China Hospital, Sichuan University, Chengdu, China and 18 control cases were included. MDM2 RNA-ISH was performed on all samples and compared with the fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) regarding their performance in detecting MDM2. Results: All samples were detected successfully using the three methods. Among 26 ALT/WDL/DDLs, all cases showed MDM2 amplification and positivity for MDM2 RNA-ISH (26/26, 100%). Twenty-four (24/26, 92.3%) of the 26 tested cases were positive for MDM2 IHC while two of them were negative. Eighteen control cases were all negative for MDM2 FISH and RNA-ISH, and 15 (15/18) cases were negative for MDM2 IHC. The sensitivity and specificity of RNA-ISH were both 100%, and those of MDM2 IHC were 92.3% and 83.3%, respectively. Diffuse staining was identified in all MDM2 RNA-ISH positive ALT/WDL/DDLs, but identified in only 8/24 (33.3%) of the MDM2 IHC positive cases. Among the 11 ALT/WDL/DDL samples evaluated on tissue microarray, the positive rate of MDM2 RNA-ISH was 100% with diffuse staining in all cases. The positive rate of MDM2 IHC was 9/11 while only 1 of the 9 cases showed diffuse staining. The result of MDM2 RNA-ISH was identical to that of MDM2 FISH and was overall consistent with that of MDM2 IHC (Kappa=0.763, P<0.001). Conclusions: In ALT/WDL/DDLs, results of MDM2 RNA-ISH are highly consistent with those of FISH. MDM2 RNA-ISH is more sensitive and more specific and has more diffuse positive signals than the IHC. The findings indicate that MDM2 RNA-ISH is highly valuable for the diagnosis and differential diagnosis of ALT/WDL/DDLs.
Biomarkers, Tumor/genetics* ; Gene Amplification ; Humans ; In Situ Hybridization, Fluorescence ; Liposarcoma/genetics* ; Proto-Oncogene Proteins c-mdm2/genetics* ; RNA

Humans ; Liposarcoma/genetics* ; Liposarcoma, Myxoid/genetics* ; Transcription Factor CHOP/genetics*