Effective Endoscopic Submucosal Dissection of a Huge Esophageal Liposarcoma: A Case Report.

This case report presents the successful endoscopic submucosal dissection (ESD) of a well-differentiated esophageal liposarcoma in a 51-year-old male with persistent dysphagia. The cause was initially diagnosed as a 10 cm pedunculated lesion extending from the upper esophageal sphincter to the mid-esophagus. An ESD was chosen over traditional surgery because it is less invasive. The procedure involved a precise submucosal injection and excision with special techniques to manage bleeding from a central vessel. Despite the extraction challenges owing to the size of the lesion, it was successfully removed orally. A histopathological examination of the 8.3×4.2×2.3 cm specimen revealed the characteristic features of a well-differentiated liposarcoma, including MDM2 and CDK4 positivity. The follow-up revealed no recurrence, and active surveillance has been performed since. This report highlights the versatility of ESD in treating significant esophageal tumors and provides evidence for its efficacy as a minimally invasive alternative.

Pleomorphic Liposarcoma Unraveled: Investigating Histopathological and Immunohistochemical Markers for Tailored Diagnosis and Therapeutic Innovations.

Liposarcomas are some of the most challenging soft tissue tumors and are subclassified into multiple subtypes with special histologic and molecular features. The peculiarities of each histopathological subtype influence the clinical behavior, management, and treatment of these neoplasms. For instance, well-differentiated liposarcomas are common soft tissue malignancies and usually display a favorable outcome. On the other hand, pleomorphic liposarcoma is the rarest, yet the most aggressive subtype of liposarcoma. This histopathological diagnosis may be challenging due to the scarce available data and because pleomorphic liposarcomas can mimic other pleomorphic sarcomas or other neoplasms of dissimilar differentiation. Nevertheless, the correct diagnosis of pleomorphic liposarcoma is of utmost importance as such patients are prone to develop local recurrences and metastases. Treatment usually consists of surgical excision along with radiotherapy and follow-up of the patients. Therefore, this review aims to assess the complex clinical, histological, and immunohistochemical features of liposarcomas in order to establish how these characteristics influence the management and prognosis of the patients, emphasizing the particularities of pleomorphic liposarcoma.

Rapid and Precise Diagnosis of Retroperitoneal Liposarcoma with Deep-Learned Label-Free Molecular Microscopy.

The retroperitoneal liposarcoma (RLPS) is a rare malignancy whose only curative therapy is surgical resection. However, well-differentiated liposarcomas (WDLPSs), one of its most common types, can hardly be distinguished from normal fat during operation without an effective margin assessment method, jeopardizing the prognosis severely with a high recurrence risk. Here, we combined dual label-free nonlinear optical modalities, stimulated Raman scattering (SRS) microscopy and second harmonic generation (SHG) microscopy, to image two predominant tissue biomolecules, lipids and collagen fibers, in 35 RLPSs and 34 normal fat samples collected from 35 patients. The produced dual-modal tissue images were used for RLPS diagnosis based on deep learning. Dramatically decreasing lipids and increasing collagen fibers during tumor progression were reflected. A ResNeXt101-based model achieved 94.7% overall accuracy and 0.987 mean area under the ROC curve (AUC) in differentiating among normal fat, WDLPSs, and dedifferentiated liposarcomas (DDLPSs). In particular, WDLPSs were detected with 94.1% precision and 84.6% sensitivity superior to existing methods. The ablation experiment showed that such performance was attributed to both SRS and SHG microscopies, which increased the sensitivity of recognizing WDLPS by 16.0 and 3.6%, respectively. Furthermore, we utilized this model on RLPS margins to identify the tumor infiltration. Our method holds great potential for accurate intraoperative liposarcoma detection.

An overview on liposarcoma subtypes: Genetic alterations and recent advances in therapeutic strategies.

Liposarcoma (LPS) is a rare malignancy of adipocytic differentiation. According to World Health Organization classification, LPS comprises of four principle subtypes Atypical lipomatous tumor/Well-differentiated liposarcoma (ATL/WDLPS), Dedifferentiated liposarcoma (WDLPS), Myxoid liposarcoma (MLPS), and Pleomorphic liposarcoma (PLPS). Each subtype can develop at any location and shows distinct clinical behavior and treatment sensitivity. ATL/ WDLPS subtype has a higher incidence rate, low recurrence, and is insensitive to radiation and chemotherapy. DDLPS is the focal progression of WDLPS, which is aggressive and highly metastasizing. MLPS is sensitive to radiation and chemotherapy, with a higher recurrence rate and metastasis. PLPS subtype is highly metastasizing, has a poor prognosis, and exhibiting higher recurrence rate. Initial histological analysis provides information for the characterization of LPS subtypes', further molecular and genetic analysis provides certain subtype specifications, such as gene amplifications and gene fusions. Such molecular genetic alterations will be useful as therapeutic targets in various cancers, including the LPS subtypes. A wide range of novel therapeutic agents based on genetic alterations that aim to target LPS subtypes specifically are under investigation. This review summarizes the LPS subtype classification, their molecular genetic characteristics, and the implications of genetic alterations in therapeutics.

Parosteal osteosarcoma with low grade chondrosarcoma and liposarcoma components. A rare histologic variant. Case report and literature review.

INTRODUCTION: conventional parosteal osteosarcoma is an uncommon malignant bone tumor, comprising 4% of all osteosarcomas. Although rare, parosteal osteosarcoma is the most common type of osteosarcoma of the bone surface. We present the clinical, histological and imaging characteristics of a rare histologic variant of a parosteal osteosarcoma, review the literature and emphasize the importance of radio-pathological correlation as well as the interpretation of a representative biopsy in order to obtain the correct diagnosis. CASE REPORT: a 36-year old woman began her condition one year prior to admission to the hospital with increased volume in the left knee and pain. Image studies showed a juxtacortical heterogeneous tumor localized on the posterior surface of the distal femoral metaphysis. An incisional biopsy was performed, with the diagnosis of a Parosteal Osteosarcoma and a wide surgical resection was undertaken. According to the findings of the surgical specimen, the diagnosis of a Parosteal Osteosarcoma with low grade chondrosarcoma and liposarcoma components was made. The knowledge of this rare parosteal osteosarcoma variant can lead the orthopedic oncologists to avoid overlooking the adipose component and provide adequate surgical margins. CONCLUSION: we present the clinical, histological and imaging characteristics of a Parosteal Osteosarcoma with low grade liposarcoma and chondrosarcoma components.

INTRODUCCIÓN: el osteosarcoma parosteal convencional es un tumor óseo maligno poco común, que comprende el 4% de todos los osteosarcomas. Aunque es poco común, el osteosarcoma parosteal es el tipo más común de osteosarcoma de la superficie ósea. Presentamos las características clínicas, histológicas y de imagen de una variante histológica rara de un osteosarcoma parosteal, revisamos la literatura y enfatizamos la importancia de la correlación radio-patológica, así como la interpretación de una biopsia representativa para obtener el diagnóstico correcto. REPORTE DE CASO: mujer de 36 años inició su cuadro un año antes de su ingreso al hospital con aumento de volumen en rodilla izquierda y dolor. Los estudios de imagen mostraron una tumoración heterogénea yuxtacortical localizada en la superficie posterior de la metáfisis femoral distal. Se realizó biopsia incisional, con diagnóstico de osteosarcoma parosteal y se realizó resección quirúrgica amplia. De acuerdo con los hallazgos de la pieza quirúrgica se realizó el diagnóstico de osteosarcoma parosteal con componentes de condrosarcoma y liposarcoma de bajo grado. El conocimiento de esta rara variante de osteosarcoma parosteal puede llevar a los ortopedistas oncólogos a considerar otros componentes y proporcionar márgenes quirúrgicos adecuados. CONCLUSIÓN: presentamos las características clínicas, histológicas y de imagen de un osteosarcoma parosteal con componentes de liposarcoma y condrosarcoma de bajo grado.

Clinical and surgical effectiveness of the multi-disciplinary standardized management model in the treatment of retroperitoneal liposarcoma: Evidence-based clinical practice experience from Fudan Zhongshan.

BACKGROUND: To assess the correlation between clinical outcomes and diagnostic accuracy of evaluations carried out by a preoperative multidisciplinary team versus standard surgical care for patients with retroperitoneal liposarcoma undergoing surgery. METHODS: This comparative study was conducted retrospectively at a specialist assessment center within Zhongshan Hospital, Fudan University, China, between April 2011 and March 2021. Patients were assigned to a multidisciplinary team or nonmultidisciplinary team cohort based on referral to the multidisciplinary team. The primary outcome measured was long-term clinical prognosis, with other outcomes including diagnostic accuracy, 30-day reoperation, duration of stay, perioperative mortality, and medical complications. To mitigate selection bias, we conducted propensity-score matching. Uni- and multivariable Cox proportional hazard models were then used to evaluate the effect of multidisciplinary teams on postoperative survival. The previously specified questionnaire was used to measure the enhancement of awareness and treatment adherence facilitated by multidisciplinary team management. Data analysis was carried out between January 2023 and August 2023. RESULTS: Of the 521 records that were screened, 139 patients were deemed eligible for inclusion and defined as the multidisciplinary team cohort. At the same time, 382 patients without multidisciplinary team management were also included during that period and defined as the nonmultidisciplinary team cohort. The multidisciplinary team cohort exhibited lower numbers of primary retroperitoneal liposarcoma but a higher tumor grade and a greater proportion of R2 resection. After propensity-score matching, the 1-, 3-, and 5-year overall survival rates were 89.5%, 70.5%, and 62.9%, respectively, in the multidisciplinary team cohort, and 77.1%, 49.8%, and 45.1% in the nonmultidisciplinary team cohort. The diagnostic consistency of the multidisciplinary team group was significantly superior to that of the nonmultidisciplinary cohort (92.5% vs 83.6%, P = .042). Although no significant links were shown with duration of stay (P = .232) and 30-day reoperation (P = .447), the multidisciplinary team participation was linked to a substantial decrease in perioperative mortality (P = .036) and postoperative complications (P = .002). Additionally, the multidisciplinary team group indicated stronger illness awareness and postoperative adherence among individuals with retroperitoneal liposarcoma. CONCLUSION: The study's findings indicate that multidisciplinary team management could result in improved clinical outcomes, higher diagnostic accuracy, and reduced duration of postoperative stays, complications, and perioperative mortality. The intervention may also enhance disease awareness and postoperative compliance in retroperitoneal liposarcoma patients who undergo surgery. However, evidence quality was deemed low, and prospective studies with robust designs are required. Nonetheless, these results are worth considering.

Myxoid Pleomorphic Liposarcoma.

Myxoid pleomorphic liposarcoma (MPLPS) shows a strong predilection for the mediastinum and can affect a wide age range. Clinically, MPLPS exhibits aggressive behavior and demonstrates a worse overall and progression-free survival than myxoid/round cell liposarcoma (MRLPS) and pleomorphic liposarcoma (PLPS). Histologically, MPLPS is characterized by hybrid morphologic features of MRLPS and PLPS, including myxoid stroma, chicken wire-like vasculature, univacuolated and multivacuolated lipoblasts, and high-grade pleomorphic sarcomatous components. In terms of molecular features, MPLPS is distinct from other lipomatous tumors as it harbors genome-wide loss of heterozygosity.

Atypical Spindle Cell/Pleomorphic Lipomatous Tumor.

Atypical spindle cell/pleomorphic lipomatous tumor (ASCPLT) is a rare soft tissue neoplasm, commonly arising in the subcutis (more common than deep soft tissue) of limbs and limb girdles during mid-adulthood. ASCPLT is histologically a lipogenic neoplasm with ill-defined margins composed of a variable amount of spindle to pleomorphic/multinucleated cells within a fibromyxoid stroma. ASCPLTs lack MDM2 amplification, but a large subset show RB1 deletion and variable expression of CD34. Though initially thought to be the malignant form of spindle cell lipoma, ASCPLTs are benign with local recurrences (∼10-15%) and no well-documented dedifferentiation or metastasis.

Clinical, Diagnostic, and Treatment Characteristics of Orbital Liposarcoma.

PURPOSE: To clarify the clinical, diagnostic, and treatment characteristics of orbital liposarcoma. DESIGN: Retrospective observational case series. METHODS: A review was performed of electronic medical records, histopathology, radiological images, and follow-up information for 21 patients with orbital liposarcoma. RESULTS: The predominant clinical manifestation of this disease was painless exophthalmos. The most frequently encountered pathological types were well-differentiated and myxoid liposarcoma. Preoperative radiological images from 15 patients showed that orbital liposarcoma initially developed in extraocular muscle in 9 patients. Furthermore, all well-differentiated liposarcomas exhibited the radiographic characteristics of irregular and ill-defined adipose tissue, whereas only 12.5% of myxoid liposarcomas had the imaging characteristics. For the patients who exclusively underwent surgery, all of those with subtotal excisions experienced recurrence, 63.6% of marginal excisions recurred, and 50% of wide excisions resulted in recurrence. However, none of the patients who underwent marginal excisions or wide excisions combined with adjuvant radiotherapy exhibited recurrence. The analysis of magnetic resonance imaging findings in 3 patients who underwent neoadjuvant radiotherapy revealed that the tumor size remained stable in a patient with well-differentiated liposarcoma, whereas another patient with the same type of tumor exhibited a gradual increase in size. Conversely, a patient with myxoid liposarcoma experienced a significant reduction in tumor size following neoadjuvant radiotherapy. CONCLUSION: Orbital liposarcoma demonstrated a propensity for developing in the extraocular muscle. The radiological images of orbital well-differentiated liposarcomas were characterized by irregular and ill-defined adipose tissue. Surgery combined with radiotherapy demonstrated potential in reducing recurrence rates. Notably, orbital myxoid liposarcoma exhibited greater sensitivity to radiotherapy compared to well-differentiated liposarcoma.

MDM2 Amplification Status in a Cohort of Well-Characterized Myxofibrosarcoma: A Clinicopathologic Analysis of 22 Tumors.

Myxofibrosarcomas (MFS) present as slowly enlarging superficial masses in elderly patients. Even though these tumors fail to exhibit a distinct immunophenotype, diagnosis is straightforward when they present in subcutaneous tissue. Intramuscular MFS, however, are more challenging to diagnose as the differential also includes dedifferentiated liposarcoma with myxoid features. The vast majority of dedifferentiated liposarcomas show MDM2 amplification, whereas limited data exists as to the MDM2 status of MFS. We sought to explore the rate of MDM2 amplification in cases of classic MFS. Our archives were searched for MFS; only subcutaneous well-sampled resections were included. FISH for MDM2 amplification was performed on each tumor. A cohort of myxoid dedifferentiated liposarcoma resections was studied for comparison. Twenty-two MFS arose in patients aged 44 to 85 years. All tumors contained an infiltrative population of atypical cells embedded in a myxoid stroma with curvilinear blood vessels. MDM2 amplification by FISH was identified in 3 (of 22; 14%) tumors. Available follow up on 17 patients (range 1-96 months; median 13 months) revealed 6 patients with local recurrence and 1 with distant metastasis. Of 3 patients with MDM2- amplified MFS, 1 experienced recurrence and died of unrelated causes, while the second was alive without disease 12 months after diagnosis. Even though the rate of MDM2 amplification by FISH in MFS appears to be low, a subset of cases may show this genetic alteration, which pathologists should be aware of to avoid misclassification as myxoid dedifferentiated liposarcomas. Further studies are necessary to determine if amplification status adds prognostic value.

Nodular cystic fat necrosis: a distinctive rare soft-tissue mass.

We report the case of a 34-year-old female who was evaluated for a right lower extremity soft-tissue mass, found to be a large cystic lesion bound by fibrous tissue containing innumerable, freely mobile nodules of fat. Her presentation suggested the diagnosis of nodular cystic fat necrosis (NCFN), a rare entity that likely represents a morphological subset of fat necrosis potentially caused by vascular insufficiency secondary to local trauma. Her lesion was best visualized using MRI, which revealed characteristic imaging features of NCFN including nodular lipid-signal foci that suppress on fat-saturated sequences, intralesional fluid with high signal intensity on T2-weighted imaging, and a contrast-enhancing outer capsule with low signal intensity on T1-weighted imaging. Ultrasound imaging offered the advantage of showing mobile hyperechogenic foci within the anechoic cystic structure, and the lesion was otherwise visualized on radiography as a nonspecific soft-tissue radiopacity. She was managed with complete surgical excision with pathologic evaluation demonstrating, similar to the radiologic features, innumerable free-floating, 1-5 mm, smooth, nearly uniform spherical nodules of mature fat with widespread necrosis contained within a thick fibrous pseudocapsule. Follow-up imaging revealed no evidence of remaining or recurrent disease on postoperative follow-up MRI. The differential diagnosis includes lipoma with fat necrosis, lipoma variant, atypical lipomatous tumor, and a Morel-Lavallée lesion. There is overlap in the imaging features between fat necrosis and both benign and malignant adipocytic tumors, occasionally making this distinction based solely on imaging findings challenging. To our knowledge, this is the largest example of NCFN ever reported.

Intra-Abdominal and Retroperitoneal Benign Lipomatous Tumors-An Extremely Rare Mimic of Liposarcoma and its Diagnostic Challenge.

Background. Lipomas are common superficial soft tissue tumors of mature adipocytes. In contrast, well-differentiated/dedifferentiated liposarcoma typically presents in the retroperitoneum as large masses. We provide clinicopathologic and follow-up details of 9 retroperitoneal/intra-abdominal benign lipomatous tumors (BLT) and discuss the utility of ancillary fluorescence in situ hybridization (FISH) in distinguishing from their malignant counterparts. Design. Clinicopathologic details and histology of 9 intra-abdominal and retroperitoneal lipomas were studied along with ancillary CD10 immunohistochemistry (IHC) and FISH for MDM2 and CDK4 amplification. Results. There were 6 females and 3 males. Median age at diagnosis was 52 years (range 36-81 years). Seven were identified incidentally and 2 presented with primary complaints. On imaging, 7 were considered suspicious for liposarcoma. Grossly, the tumors ranged from 3.4 to 41.2 cm (median 16.5 cm). Histologically, all cases showed well-differentiated BLT, further classified as lipoma (n = 7; 1 with metaplastic ossification, 2 with prominent vessels, and 4 ordinary lipomas) and lipoma-like hibernoma (n = 2)-the latter 2 showed intramuscular lesions with interspersed brown fat. CD10 IHC showed strong staining in the 2 hibernomas, whereas the staining was weak in the remaining. MDM2 and CDK4 amplification were negative by FISH in all. Follow-up (median 18 months) did not show recurrence on clinical or imaging evaluation. Conclusion. Retroperitoneal/intra-abdominal BLT are extremely rare and are indistinguishable clinically and radiographically from liposarcoma. This necessitates molecular confirmation even when the histology is convincingly benign, for a confident diagnosis. Our cohort shows that conservative excision without removal of abutted organs is sufficient in most cases.

Orbital Liposarcoma Progression From a Well-Differentiated to a Dedifferentiated Type in a Young Patient.

A young male patient presented with unilateral proptosis of the left eye. Laboratory tests and an initial computed tomography scan of the orbit were compatible with euthyroid orbitopathy. He subsequently underwent decompression surgery for unfavorable cosmesis and corneal exposure symptoms with good results, but returned 1 year later for recurrence of proptosis. There was a superomedial fatty density extraconal mass on computed tomography scan. A biopsy done a year later confirmed the diagnosis of well-differentiated liposarcoma from the previously noted mass and a dedifferentiated component in the newly appeared mass in the intraconal space. Orbital exenteration with radial forearm free flap was performed followed by orbital radiotherapy. No disease recurrence or metastasis was seen on follow-ups for 7 years since undergoing treatment.

MDM2 FISH testing criteria in adipose tissue tumors with mature adipocytic morphology - A resection case-based study.

The current criteria for utilizing MDM2 Fluorescence In Situ Hybridization (FISH) in adipose-derived tumors were first introduced in 2015 and have been widely adopted. However, these criteria may fail to identify some atypical lipomatous tumors / well-differentiated liposarcoma (ALT/WDL) with mature adipocytic morphology in clinical practice, possibly due to the fact that the existing criteria are primarily based on biopsy cases. Hence, a criterion based on resection cases is needed. In this study, we included 87 adipose tissue tumors with mature adipocytic morphology which were first resected, as well as 9 consultation cases and 25 recurrent resection cases. The final diagnosis was based on MDM2 amplification status. Among the 87 first-time resection cohort, MDM2 FISH amplification was observed in only 2 (5%) of the 39 superficial cases. Marginal infiltration was significantly different in both the MDM2 FISH negative and positive groups (p < 0.05). Of the 37 intramuscular tumors, 17 (46%) showed MDM2 FISH amplification. The MDM2 amplification positive group had a larger tumor size than MDM2 amplification negative group (p = 0.042). Tumors of larger size (≥11 cm) were highly correlated with MDM2 amplification (p = 0.003), but still, 35.3% of the MDM2 amplification-positive cases had tumor sizes less than 11 cm. Eight (66.7%) out of twelve retroperitoneal/ pelvic cases were MDM2 FISH positive. Among the 25 recurrent cases, twenty (80%) of them had MDM2 FISH amplification. In conclusion, we recommend MDM2 FISH for: 1. superficial cases with marginal infiltration based on adequate margin sampling; 2. all intramuscular tumors, retroperitoneal/pelvic tumors and recurrent tumors, both in resection cases and biopsy cases.

Atypical lipomatous tumor/well differentiated liposarcoma and related mimics with updates. When is molecular testing most cost-effective, necessary, and indicated?

The classification and work-up of adipocytic neoplasms remains challenging and sometimes controversial. Since its initial description by Dr. Enterline, the variety of subtypes and morphological appearances considered to represent the spectrum of atypical lipomatous tumor/well differentiated liposarcoma (ALT/WDL) has expanded, resulting in significant morphologic overlap with other entities, including the recently described atypical spindle cell/pleomorphic lipomatous tumor (ASPLT), conventional spindle cell/pleomorphic lipoma (SPL), and so-called "low-grade" forms of dedifferentiated liposarcoma (DL). Nevertheless, the distinction of most examples of ALT/WDL from lipomas/lipoma-like lesions is easily performed on routine histologic examination but can be problematic if the characteristic atypical cells are poorly represented, particularly in small biopsy specimens, obscured by other cellular elements (inflammation), or simply not recognized. The discovery that lipomatous tumors harbor specific and unique karyotypes and molecular events has resulted in ancillary tests that can help provide more accurate diagnoses, especially in less-than-optimal scenarios. Confirmation of MDM2 immunohistochemical over-expression and detection of the MDM2 gene rearrangement via fluorescent in situ hybridization (FISH) have proven particularly reliable and useful. While FISH analysis for MDM2 gene amplification may be helpful for confirming (or excluding) ALT/WDL, it also can lead to overutilization and overdependence. Furthermore, a small subset of otherwise typical ALT/WDL lack MDM2 gene amplification, employing alternative molecular pathways. The recent recognition of ASPLT has introduced a tumor easily mistaken morphologically for ALT/WDL, often exhibiting bizarre and pleomorphic lipoblasts, but lacking the underlying molecular abnormalities and subsequent risk of dedifferentiation. ASPLT also have overlapping features with the better-established SPL but with a greater tendency to locally recur and more frequent involvement of the distal extremities. The precise criteria separating cellular forms of ALT from what some consider "low grade" forms of DL remains controversial and inconsistently applied, even among individual pathologists within institutions. Given their underlying shared cytogenetic abnormality, molecular testing has no utility in this distinction. Herein is a comprehensive historical overview of ALT/WDL, with updates on its distinction from other similar lipomatous tumors and DL, including practical evidence-based criteria for the appropriate cost-effective use of MDM2 testing.

Paratesticular Dedifferentiated Liposarcoma with Rhabdomyoblastic Differentiation: A Case Report and Review of the Literature.

Liposarcomas of the paratesticular tissue is a rare pathological entity. The symptoms are similar to inguinal hernias or hydroceles. We present the case of an 84-year-old man with a rare paratesticular liposarcoma that manifested as painless right hemiscrotal swelling. Testicular tumour markers were negative. Imaging revealed a heterogeneous mass with a fat component. He underwent a radical orchiectomy on the left side to remove the associated mass. This revealed dedifferentiated liposarcoma (DDLS) with rhabdomyoblastic differentiation and MDM2 amplification. The surgical margins were negative, and the patient had a metastatic workup that included magnetic resonance imaging (MRI) of the abdomen and pelvis. Because of the disease's rarity, there is no clear agreement on radiotherapy and chemotherapy roles.