Spermatic cord malignancies are a scarce modality and liposarcoma of spermatic cord is even a rarer condition encountered. Liposarcoma is usually a slowly progressive, non-tender, well circumscribed mass of variable shapes owing to conformity to fascial compartments. We are reporting a case of 65-year-old male, with a two-month history of initially tender and later non-tender mass in the scrotum, above the testis. Ultrasonography showed a right mid inguinal mass measuring 6x3x3 cm at the superior pole of the right testis and small fluid around the right testis. Fine needle aspiration cytology (FNAC) of the right inguinal mass revealed a spindle cell neoplasm. The patient underwent right inguinal radical orchiectomy with local wide excision of the sarcoma of the spermatic cord origin. Final histopathology confirmed dedifferentiated liposarcoma. No adjuvant treatment was offered and the patient was put on surveillance. Follow-up of more than 10 months has not revealed any local recurrence, regional or non-regional lymph nodes, or systemic metastasis.

UNASSIGNED: Liposarcoma is a malignant tumor that originates from adipose tissue and can occur in any part of the body. There is currently no clear conclusion on whether there are significant differences in prognosis between liposarcoma at different anatomical locations, especially retroperitoneal liposarcoma (RLPS) and non retroperitoneal liposarcoma (NRLPS). The aim of this study is to reveal whether there are differences in prognosis between these two locations of liposarcoma, and further explore the fundamental reasons behind these differences.
UNASSIGNED: We conducted an in-depth investigation into the factors affecting the prognosis of patients with liposarcoma by analyzing the data from the Surveillance, Epidemiology, and End Results Program (SEER) database. Then, we used propensity score matching (PSM) to balance these prognostic factors for comparative analysis of survival between RLPS and NRLPS. In addition, by analyzing transcriptome and whole exome data from TCGA and the Japan Genotypic Phenotype Archive (JGA), we identified genes with significant expression differences and explored changes in the immune microenvironment.
UNASSIGNED: Through analysis of RLPS and NRLPS patients in the SEER database, we observed significant prognostic differences between the two groups, with RLPS exhibiting worse prognosis (p < 0.001). Even after adjusting for confounding factors through PSM, these survival rate differences remained significant, with RLPS still showing worse prognosis (p = 0.017). Furthermore, our analysis of transcriptomic data led to the identification of 467 differentially expressed genes. Additionally, we noted significant differences in the immune microenvironment and whole exome sequencing data between the two groups.
UNASSIGNED: There are significant differences between patients with RLPS and NRLPS. Therefore, from clinical research to treatment strategies, RLPS and NRLPS should be considered as two distinct types of tumors, necessitating differentiated approaches for their study and treatment.

BACKGROUND: Mucinous liposarcoma myxoid liposarcoma is a malignant mucoid soft tissue tumor derived from undifferentiated stromal cells in perivascular, subbody cavity and intermuscular space, and composed of cells at different stages of differentiation from preadipocytes to mature cells. In rare cases, it may change from lipoma malignancy. The main manifestations is painless mass, relatively slow growth, the course can last decades, the prevalence of liposarcoma in the population is 14% to 18%, mainly in adults, male prevalence is higher than women, but not significant. The main good hair part is the thigh, have mucinous sex, high differentiation type, dedifferentiation type, polymorphic type. Clinical diagnosis is difficult, and there are no obvious symptoms in the early stage, so the diagnosis should be combined with B ultrasound, MRI, CT, and other auxiliary examinations. The gold standard is pathological examination. In December 2023, our department admitted a patient with a mucinous abdominal mass. The report is as follows.
METHODS: Does liposarcoma metastasize? Is any chemotherapy required after surgery? Will it ever relapse in the future? What is the survival period after surgery?
METHODS: Mucinous liposarcoma.
METHODS: Surgical resection of the sarcoma.
RESULTS: The nodule sample was 33 * 28 * 13 cm, with complete capsule, gray and yellow sections, fine texture, soft, gray, red, grayish, and yellow mucoid nodules in some areas, and the maximum diameter of the nodules was 21cm. Immunohistochemistry was: CD34 (+), CDK 4 (+), CK (-), Desmin (weak +), Ki67 (index 5%), MDM 2 (-), p16 (weak +), S-100P (+), Vimentin (+), BCL-2 (+). He was also sent to the Department of Pathology of Peking Union Medical College Hospital for consultation with Professor Lu Zhaohui, whose consultation opinion was in line with myxoliposarcoma.
CONCLUSIONS: Retroperitoneal liposarcoma is a common retroperitoneal tumor, but it is relatively rare in clinical practice; the overall morbidity is low, mainly manifested as abdominal pain and abdominal distension, abdominal distension, and a long course of disease; it is not sensitive to radiotherapy and chemotherapy, and should be closely follow up by CT examination to understand the recurrence and metastasis.

UNASSIGNED: Among liposarcomas, well-differentiated liposarcoma and dedifferentiated liposarcoma are the most common. The majority of these tumors are found in deep retroperitoneum or extremities. When found outside the retroperitoneum, these adipose-derived tumors are known as atypical lipomatous tumors (ALT). Superficial ALT are particularly rare; thus, little is known about their clinical presentation, genomic status, and management. Here, we present the case of a 54-year-old man with an intermittently bothersome, slowly growing mass on his left upper back for over 2 years, which was incidentally diagnosed as ALT. This patient\'s ALT, however, showed a profound degree of pleomorphism with MDM2 and control centromere 12 (CEP12) coamplification and negative CD34 and S100 and RB1 expression, unlike most other ALT described in the literature. This case report details the diagnostic workup and histopathological findings for adipose tumors and summarizes the different subtypes, including atypical spindle cell/pleomorphic lipomatous tumor, pleomorphic liposarcoma, and spindle cell/pleomorphic lipoma, with brief discussion on management.

BACKGROUND: This is a multicentre, single-arm, phase II study aimed at further exploring the activity of trabectedin as second-/further-line treatment in retroperitoneal leiomyosarcoma (LMS) and well-differentiated/dedifferentiated liposarcoma (LPS).
METHODS: The primary endpoint was the growth modulation index (GMI) defined as the ratio between PFS under trabectedin (PFS) and during previous chemotherapy treatment: time to progression (TTP-1). Secondary endpoints were objective response rate (ORR) and PFS. As per protocol, patients were considered responders if the GMI was >1.33, non-responders if <0.75 and neither if 0.76-1.32.
RESULTS: Overall 91 patients were assessable for the primary endpoint (32 patients with LMS and 59 patients with LPS): the median number of cycles received was 6.0 (Q1-Q3 3.0-12.0), and the main reason for treatment discontinuation was disease progression in 72% of patients. The median PFS was 6.0 months, while the median TTP1 was 7.5 months (8.1 and 6.4 months for LMS and LPS, respectively). Thirty-three patients [52%, 95% confidence interval (CI) 36% to 58%, P = 0.674, odds of response 1.1] had a GMI >1.33 (LMS 46%, 95% CI 26% to 67%, odds of response 0.85; LPS 56%, 95% CI 40% to 72%, odds of response 1.3). Overall, in LPS we observed 15/47 patients with a GMI <0.5 and 15/47 patients with a GMI >2. Among LMS patients, 9/26 had a GMI <0.5 and 10/26 had a GMI >2. Overall, ORR (complete response + partial response) was 16% (24% for LMS and 12% for LPS).
CONCLUSIONS: While the primary endpoint of the study was not met, we noticed a subgroup of patients with a markedly discrepant TTP with trabectedin in comparison to previous therapy (GMI <0.5 or >2, the latter including some patients with a long TTP with trabectedin). A mismatch between PFS and overall survival was observed, possibly due to the natural history of the two different histologies and the availability of further lines in LMS.

UNASSIGNED: Atypical spindle cell/pleomorphic lipomatous tumor is categorized as a benign lipomatous tumor, but various MRI findings pose accurate diagnostic challenges. In our case, both MRI and PET/CT scans indicated the possibility of atypical lipomatous tumor/well-differentiated liposarcoma or dedifferentiated liposarcoma. Needle biopsy suggested benign to low-grade malignancy; hence, we opted for the wide resection. The final diagnosis of atypical spindle cell/pleomorphic lipomatous tumor was confirmed through histopathology analysis, including immunohistochemistry and fluorescence in situ hybridization. Since achieving an accurate diagnosis solely through imaging can be challenging, histopathology remains essential.

OBJECTIVE: Cure models are a useful alternative to Cox proportional hazards models in oncology studies when there is a subpopulation of patients who will not experience the event of interest. Although software is available to fit cure models, there are limited tools to evaluate, report, and visualize model results. This article introduces the cureit R package, an end-to-end pipeline for building mixture cure models, and demonstrates its use in a data set of patients with primary extremity and truncal liposarcoma.
METHODS: To assess associations between liposarcoma histologic subtypes and disease-specific death (DSD) in patients treated at Memorial Sloan Kettering Cancer Center between July 1982 and September 2017, mixture cure models were fit and evaluated using the cureit package. Liposarcoma histologic subtypes were defined as well-differentiated, dedifferentiated, myxoid, round cell, and pleomorphic.
RESULTS: All other analyzed liposarcoma histologic subtypes were significantly associated with higher DSD in cure models compared with well-differentiated. In multivariable models, myxoid (odds ratio [OR], 6.25 [95% CI, 1.32 to 29.6]) and round cell (OR, 16.2 [95% CI, 2.80 to 93.2]) liposarcoma had higher incidences of DSD compared with well-differentiated patients. By contrast, dedifferentiated liposarcoma was associated with the latency of DSD (hazard ratio, 10.6 [95% CI, 1.48 to 75.9]). Pleomorphic liposarcomas had significantly higher risk in both incidence and the latency of DSD (P < .0001). Brier scores indicated comparable predictive accuracy between cure and Cox models.
CONCLUSIONS: We developed the cureit pipeline to fit and evaluate mixture cure models and demonstrated its clinical utility in the liposarcoma disease setting, shedding insights on the subtype-specific associations with incidence and/or latency.

Retroperitoneal liposarcoma during pregnancy is rare and poses significant diagnostic challenges, even for experienced specialists. We present a case report of a 27-year-old female patient, 15 weeks pregnant, who was admitted to the hospital due to a massive retroperitoneal liposarcoma. The patient underwent surgical resection of the tumor. Postoperative pathology confirmed a diagnosis of well-differentiated liposarcoma. Although liposarcoma during pregnancy is rare and challenging to diagnose, CT or MRI plays a crucial role in its detection. The recurrence rate depends on the pathological stage, histological grade, and ability to resect the tumor.

Lipomatous pseudohypertrophy of the pancreas (LPH) is a rare disease in which the pancreatic parenchyma is replaced with mature adipose tissue. It is an idiopathic condition whose diagnosis is made based on histopathological analyses. Herein, we report the case of a 50-year-old male patient with a lipomatous mass in the head of the pancreas on computed tomography for close examination of a renal tumor. We suspected liposarcoma, and laparotomy was performed. However, histological analyses revealed LPH. Several imaging findings of LPH can enable a noninvasive diagnosis and help its clinical approach.

Liposarcoma (LPS) is a rare soft tissue sarcoma that develops from the differentiation of fat cells, typically occurring in the lower extremities and retroperitoneal space. Depending on its histological morphology and molecular changes, LPS can be divided into various subtypes, each exhibiting distinct biological behaviors. During treatment, especially for LPS arising in the retroperitoneum, the extent and quality of the initial surgery are critically important. Treatment strategies must be tailored to the specific type of LPS. Over the past few decades, the treatment of LPS has undergone numerous advancements, with new therapeutic approaches such as targeted drugs and immunotherapies continually emerging. This paper reviews the biological characteristics, molecular alterations, as well as surgical and pharmacological treatments of various LPS subtypes, with the aim of enhancing clinicians\' understanding and emphasizing the importance of individualized precision therapy. With a deeper understanding of the biological characteristics and molecular alterations of LPS, future treatment trends are likely to focus more on developing personalized treatment plans to better address the various types of LPS.