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.

PSMA and FDG PET/CT Findings in Patient With Dedifferentiated Liposarcoma and Prostate Cancer Metastases.

ABSTRACT: Dedifferentiated liposarcoma is an extremely rare and highly malignant tumor. We demonstrated a case of a 75-year-old man with significantly PSMA-avid and mildly FDG uptake-dedifferentiated liposarcoma in the retroperitoneal area. The double-tracer (PSMA and FDG) PET scans could further contribute to differential diagnosis and the following treatment strategy for patients who were suspected with prostate cancer metastases and other malignant tumors simultaneously.

Intense FDG Uptake in Well-Differentiated Inflammatory Liposarcoma of the Retroperitoneum.

ABSTRACT: Inflammatory variant of well-differentiated liposarcoma is a rare subtype of liposarcoma, and its imaging features have been rarely reported. We describe FDG PET/CT findings in a case of well-differentiated inflammatory liposarcoma. The tumor showed no detectable fat and intense FDG uptake and caused diffuse FDG uptake of the bone marrow due to paraneoplastic leukemoid reaction. Microscopically, there were extensive inflammatory infiltrates in the tumor, which may contribute to the intense FDG uptake. This case indicates that although well-differentiated liposarcoma usually shows low-grade FDG uptake, inflammatory variant of well-differentiated liposarcoma can show intense FDG uptake mimicking high-grade liposarcoma.

Recurrence of locally invasive retroperitoneal dedifferentiated liposarcoma shortly after surgery: A case report and literature review.

RATIONALE: Retroperitoneal dedifferentiated liposarcoma (RPDDL) is an uncommon malignancy, which often remains undetected for many years due to having adequate space in the retroperitoneal cavity and lacking clinical manifestations in the early stage of the disease. Surgical procedure is usually used as the first choice for treatment. However, it is prone to local recurrence after the operation, resulting in an unfavorable prognosis. Our aim is to draw useful lessons from the new case and provide some experience for management of the disease. PATIENT CONCERNS: We describe a 55-year-old male patient who was admitted for a 3-week history of persistent dull ache of the left waist. A large mass of the left upper abdomen was palpated in physical examination. Moreover, the imaging examination revealed that the diameter of the mass was about 21 cm, and some adjacent vital organs were invaded, which brought great challenges to complete surgical resection. DIAGNOSIS: The postoperative pathological results confirmed that the mass was RPDDL with invasion of the surrounding vital structures including pancreas, spleen, left adrenal gland, left kidney, and vasculature with tumor emboli. INTERVENTIONS: Surgical resection of the mass was performed by our multidisciplinary team. The patient received chemotherapy 1 month after surgery. OUTCOMES: The effect of chemotherapy seemed to be unsatisfactory. Local multifocal recurrence of the tumor was considered about 2 months after surgery. Finally, he gave up any treatments and died of the disease. LESSONS: Regular physical examination and ultrasound screening may detect the disease as early as possible, especially for high-risk group aged 60 to 70, which should be popularized. Incomplete resection, vascular invasion, and interruption of postoperative treatment may lead to an unfavorable prognosis. Therefore, we think that patients with the disease may benefit from complete surgical resection and uninterrupted adjuvant therapy.

[Well Differentiated Liposarcoma of a Lung:Report of a Case].

A 61-year-old woman was referred for further evaluation of an intracystic nodule in her left upper lung. Computed tomography( CT) showed a 15 mm nodule in a pulmonary cyst adjacent to aortic arch and mediastinum. Fluorodeoxyglucose-positron emission tomography (FDG-PET)-CT showed little uptake of FDG in the lesion. No abnormality was found in the bronchoscopy findings. On imaging findings, the possibility of pulmonary aspergilloma was considered, but the serological findings were inconsistent, and surgical resection of the lesion was performed for both diagnosis and treatment. The final pathohistological diagnosis was well differentiated liposarcoma. No adjuvant therapy was performed and the patient has been well without recurrence for 2 years after the surgery. We report a rare case of well differentiated liposarcoma of a lung mimicking pulmonary aspergilloma.

Diffuse intra-abdominal sarcomatosis in myxoid pleomorphic liposarcoma.

We present a case of an extremely rare type of soft-tissue sarcoma with an atypical clinical presentation. The patient, a female in her 20s with Li Fraumeni syndrome, had prior surgery for a large intra-abdominal tumour that was given the diagnosis of malignant myxoid spindle cell neoplasm. Her recurrence manifested as diffuse intra-abdominal sarcomatosis for which she ultimately underwent subtotal debulking with palliative intent. Final pathology rendered the diagnosis of myxoid pleomorphic liposarcoma, a newly described entity, distinct from the more common liposarcoma subtypes. The optimal treatment for this typically aggressive disease is currently unknown; until that is better defined, management should be carried out by sarcoma specialists.

Retroperitoneal liposarcoma: Case of a giant tumour inside the abdomen.

Retroperitoneal liposarcomas are rare malignant tumours that often grow rapidly in size and become symptomatic lat e in t he disease course, posing diagnostic a nd therapeutic challenges. Although abdominal imaging can rel iab ly diagnose the tumour, definitive diagnosis is only p ossib le th rough bio psy af ter surgical excision , w hich remains the primary treatment modality for these tumours. Long- term sur v ival is p rimarily determ ined throu gh histologic grade and post-resection tumour margins. We report t he case of a 43-year-o ld male patient, see n at Dr Ruth KM Pfau Hospital Karachi, who under went successful surgical excision for a well-differentiated retroperitoneal liposarcoma an d had no rad io gr aphic evidence o f local recurrence at both 3 and 12-month follow-ups.

Pleomorphic Liposarcoma Initially Presenting with Multiple Organ Involvement Including the Heart.

A 42-year-old man visited our hospital due to a gradually swelling subcutaneous mass on the back of the right shoulder. The biopsy specimen was diagnosed pathologically as pleomorphic liposarcoma. Systemic computed tomography and 18F-fluorodeoxyglucose positron emission tomography revealed multiple organ metastases, including involvement of the heart, skin, liver, bone, and lung. Six cycles of doxorubicin plus ifosfamide initially controlled the disease. However, newly developed lung metastases grew rapidly during subsequent cycles of chemotherapy, and the patient died 10 months after the initial diagnosis. The initial presentation of multiple organ involvement, including the heart, is a rare clinical manifestation of pleomorphic liposarcoma.

Dedifferentiated liposarcoma with heterologous rhabdomyosarcomatous differentiation in the bone marrow.

We present a case of advanced well-differentiated liposarcoma transforming to dedifferentiated liposarcoma in the bone marrow.Our patient presented with 5 weeks of worsening flank pain. He was found to have profound leukocytosis, thrombocytopenia, and normocytic anemia. Imaging showed a dominant retrocaval mass concerning for viable disease. Bone marrow biopsy revealed dedifferentiated liposarcoma with heterologous rhabdomyosarcomatous differentiation. He underwent 3 cycles of eribulin and subsequently developed complications of his increasingly aggressive liposarcoma. He was transitioned to hospice care and died 3 months after initial bone marrow biopsy. While exceedingly rare, it is possible for liposarcoma to metastasize to the bone marrow and cause rapid progression to death. In patients with high-grade liposarcoma, new cytopenia, leukocytosis, elevated granulocyte colony stimulating factor, and/or leukoerythroblasosis on peripheral smear should prompt bone marrow biopsy for early detection of this rare disease entity.

Resection of previously inoperable retroperitoneal liposarcoma.

We present a case of successful resection of a large right upper quadrant retroperitoneal dedifferentiated liposarcoma involving multiple adjacent organs, initially considered inoperable in a patient in his 40s. This case highlights the importance of extensive preoperative planning and a multidisciplinary approach in achieving a greater chance of curative resection. Preoperative optimisation included neoadjuvant chemotherapy, concurrent portal vein embolisation and hepatic vein embolisation. The patient then underwent en-bloc resection, including total pancreatectomy, hemihepatectomy and vena caval resection in conjunction with extracorporeal membrane oxygenation and percutaneous venovenous bypass.

A CT-based radiomics classification model for the prediction of histological type and tumour grade in retroperitoneal sarcoma (RADSARC-R): a retrospective multicohort analysis.

BACKGROUND: Retroperitoneal sarcomas are tumours with a poor prognosis. Upfront characterisation of the tumour is difficult, and under-grading is common. Radiomics has the potential to non-invasively characterise the so-called radiological phenotype of tumours. We aimed to develop and independently validate a CT-based radiomics classification model for the prediction of histological type and grade in retroperitoneal leiomyosarcoma and liposarcoma. METHODS: A retrospective discovery cohort was collated at our centre (Royal Marsden Hospital, London, UK) and an independent validation cohort comprising patients recruited in the phase 3 STRASS study of neoadjuvant radiotherapy in retroperitoneal sarcoma. Patients aged older than 18 years with confirmed primary leiomyosarcoma or liposarcoma proceeding to surgical resection with available contrast-enhanced CT scans were included. Using the discovery dataset, a CT-based radiomics workflow was developed, including manual delineation, sub-segmentation, feature extraction, and predictive model building. Separate probabilistic classifiers for the prediction of histological type and low versus intermediate or high grade tumour types were built and tested. Independent validation was then performed. The primary objective of the study was to develop radiomic classification models for the prediction of retroperitoneal leiomyosarcoma and liposarcoma type and histological grade. FINDINGS: 170 patients recruited between Oct 30, 2016, and Dec 23, 2020, were eligible in the discovery cohort and 89 patients recruited between Jan 18, 2012, and April 10, 2017, were eligible in the validation cohort. In the discovery cohort, the median age was 63 years (range 27-89), with 83 (49%) female and 87 (51%) male patients. In the validation cohort, median age was 59 years (range 33-77), with 46 (52%) female and 43 (48%) male patients. The highest performing model for the prediction of histological type had an area under the receiver operator curve (AUROC) of 0·928 on validation, based on a feature set of radiomics and approximate radiomic volume fraction. The highest performing model for the prediction of histological grade had an AUROC of 0·882 on validation, based on a radiomics feature set. INTERPRETATION: Our validated radiomics model can predict the histological type and grade of retroperitoneal sarcomas with excellent performance. This could have important implications for improving diagnosis and risk stratification in retroperitoneal sarcomas. FUNDING: Wellcome Trust, European Organisation for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group, the National Institutes for Health, and the National Institute for Health and Care Research Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research.

Pleomorphic liposarcoma of the extremity with solitary huge liver metastasis at initial diagnosis treated with conversion surgery combined with adjuvant chemotherapy: a case report.

BACKGROUND: Pleomorphic liposarcoma is the rarest subtype of liposarcoma. Pleomorphic liposarcomas are generally unresponsive to chemotherapy and radiotherapy. Moreover, metastasis in the liver, as the first and sole site, from a primary extremity soft tissue sarcoma, including pleomorphic liposarcoma, is extremely rare. Information regarding the appropriate management of these lesions is limited. CASE PRESENTATION: A 50-year-old Japanese woman presented with a mass in the left thigh. Imaging examination revealed a soft tissue sarcoma on the left posterior thigh. The tumor was histologically diagnosed as pleomorphic liposarcoma. Computed tomography examination for assessment of metastases incidentally detected a huge liver mass. Wide excision of sarcoma was performed prior to chemotherapy. Right trisectionectomy was necessary to achieve hepatic clearance; however, the future liver remnant volume was insufficient. Therefore, we decided to administer anthracycline-based chemotheraphy to shrink the tumor. After seven courses of adriamycin-based chemotherapy, the liver tumor size was reduced from 211 mm × 106 mm × 180 mm to 105 mm × 66 mm × 90 mm. Finally, a right hemihepatectomy was performed. The patient was continuously monitored and was metastasis or local recurrence free within 5 months after liver surgery. CONCLUSION: Chemotherapy is effective in some cases for the treatment of unresectable liver metastases of pleomorphic liposarcoma, and complete resection is possible with conversion surgery. If the patient's general condition permits, anthracycline-based chemotherapy can be used for the treatment of stage 4 pleomorphic liposarcoma.

Giant atypical lipomatous tumors of the thigh: a case series.

BACKGROUND AND AIM: Atypical Lipomatous Tumors (ALTs) are low-grade locally aggressive soft tissue tumors. Deep large sized ALTs of the thigh can cause significant functional impairment due to their mass effect. Surgical resection, which is the treatment of choice for these lesions, can be a though procedure, especially if the neoplasm comes in proximity with noble structures such as large sized arteries or nerves. The aim of our study is to assess risks and effectiveness of surgical resection, evaluating complications, local recurrences and post-operative functionality. METHODS: We evaluated all the giant ALT (larger diameter of 10 cm or more) of the thigh that received surgery in our institution between 2017 and 2022. Each patient's personal data and tumor size were evaluated. The quality of surgical margins was analyzed. MRI scans were performed both pre-operatively and during patients' follow-up. Lower limb's functional status was assessed using the MSTS score before and after surgery. Intra-operative and post-operative complications were recorded, as well as local recurrences. RESULTS: Twentythree cases were included in our study. Tumors' mean major diameter was 19.1cm. The mean pre-operative MSTS score was 25.9. Only one case suffered from significant post-operative complications. Only 2 of our cases (8.7%) developed a local recurrence after surgery. The mean post-operative MSTS score was 29.1 Conclusions: A careful surgical resection can be effective in treating giant ALTs of the thigh in reason of good functional outcomes, low complications risks and reasonable local recurrence rates.

Prognostic value of clinical and MRI features in the screening of lipomatous lesions.

BACKGROUND AND OBJECTIVES: Differentiation of lipomatous tumors mostly requires diagnostic biopsy but is essential to decide for the most adequate therapy. This study aims to investigate the prognostic value of available clinical and radiological features with regard to malignancy of the lesion, recurrence and survival. METHODS: In this retrospective cohort study, 104 patients with a biopsy-proven lipomatous tumor between 2010 and 2015 and a minimum clinical follow-up of two years were enrolled. Next to clinical features (age, gender, location of the lesion, histopathologic diagnosis, stage of disease, time to recurrence and death), MRI parameters were recorded retrospectively and blinded to the histological diagnosis. RESULTS: Malignant lipomatous tumors were associated with location in the lower extremities and MRI features like thick septation (>2 mm), presence of a non-adipose mass, foci of high T2/STIR signal and contrast agent enhancement. A non-adipose mass was a predictor for recurrence and inferior overall survival, while lesions with high T2/STIR signal showed higher risk of recurrence only. In combination, clinical and radiological features (lower extremities, septation > 2 mm, existence of non-adipose mass, contrast enhancement, and foci of high T2/STIR signal) predicted a malignant lipomatous tumor with an accuracy of 0.941 (95% CI of 0.899-0.983; 87% sensitivity, 86% specificity). CONCLUSION: Localization and characteristic MR features predict malignancy in most lipomatous lesions. Non-adipose masses are a poor prognostic factor, being associated with tumor recurrence and disease-related death.