An Atypical Spindle Cell/Pleomorphic Lipomatous Tumor of the Thigh With a Difficult Imaging Diagnosis That Mimicked a Malignant Lipomatous Tumor.

ABSTRACT: 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.

From Benign Lipoma to G3 Liposarcoma: Contrast-Enhanced Ultrasound Reveals Tumor Microperfusion and Indicates Malignancy.

OBJECTIVE: Lipomatous soft tissue tumors (STT), ranging from benign lipomas to malignant liposarcomas, require accurate differentiation for timely treatment. Complementary to MRI, Contrast-enhanced ultrasound (CEUS) is emerging as a promising tool, providing insight into tumor microperfusion in real-time. This study aims to explore the potential of preoperative CEUS in differentiating benign lipomatous tumors from malignant liposarcoma subtypes. METHODS: Eighty-seven patients with lipomatous STT scheduled for surgery were enrolled. Clinical and MRI assessments were conducted to obtain general tumor characteristics. CEUS was used for a standardized tumor perfusion evaluation. Perfusion analysis included peak enhancement, rise time, wash-in perfusion index, and wash-out rate, reflecting the perfusion kinetics. Histopathological results were obtained for every STT and compared to perfusion characteristics. RESULTS: In total, 48 lipoma, 23 ALT and 11 liposarcoma were identified. Significant differences in tumor microperfusion were demonstrated, with higher perfusion levels indicating higher malignancy (Peak enhancement [a.u.] of Lipoma: 145 ± 238; ALT: 268 ± 368; Liposarcoma: 3256 ± 4333; p (ALT vs. Liposarcoma) < 0.001). A perfusion-based identification of a benign lipoma or ALT versus sarcoma resulted in a positive predictive value of 93%. Patient-related factors (age, gender, BMI, ASA score, smoking status) had no significant impact on the CEUS-based perfusion parameters. CONCLUSION: Our study suggests CEUS as a capable non-invasive tool for improving preoperative assessment of lipomatous STT. It can assist in the distinction between benign and malignant STT, accelerating treatment decisions and enhancing patient outcomes. Significant correlations between CEUS-derived parameters and malignancy highlight its risk assessment potential.

Post-RFA Pulmonary Vein Stenosis Mimicking Lymphangitic Carcinomatosis in a Patient With History of Liposarcoma.

ABSTRACT: A 58-year-old man with resected liposarcoma exhibited persistent irregular interlobular septal thickening of lung on CT concerning lymphangitic metastasis. FDG PET/CT was positive in these foci. There was a narrowing of the pulmonary veins, which had not been seen on the imaging conducted prior to radiofrequency ablation therapy for atrial fibrillation. Lung perfusion scanning demonstrated more extensive hypoperfusion. This case highlights the diagnostic pitfalls of interstitial thickening of the lung in cancer patients. Meticulous history review and nuclear imaging helped distinguish the postablation pulmonary venous stenosis from metastatic spread to the lung interstitium.

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.

Retrospective analysis of radiological investigation of surgically excised head and neck lipomas.

PURPOSE: Differentiating benign lipomas from malignant causes is challenging and preoperative investigative guidelines are not well-defined. The purpose of this study was to retrospectively identify cases of head and neck lipomas that were surgically resected over a 5-year period and to identify the radiological modality chosen and features discussed in the final report. Multidisciplinary outcomes and pathology reports were examined with a view to identifying high risk features of a lipoma to aid in future risk stratification. METHODS: Retrospective chart review of pathology characteristics, radiological features (modality, size, calcifications, septations, globular/nodular foci), multidisciplinary discussion and history of presenting complaint was performed. RESULTS: Two liposarcomas and 138 lipomas were identified. Twenty-two percent of all lipomas received radiological investigation. Twenty-two percent of imaging referrals were possibly inappropriate. Furthermore, radiological features suggestive of malignancy were not present in the final radiology report, X2 = 28.8, p < 0.0001. CONCLUSION: As expected, the incidence of liposarcoma is low. There is limited awareness of radiology referral guidelines superimposed with a tendency to over-investigate lipomas. Furthermore, radiological features suggestive of malignancy were inconsistently reported on and not documented in multidisciplinary discussions. Therefore, we propose a multidisciplinary checklist for referring physicians and radiologists to aid in diagnostic work-up.

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.

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.

[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.

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.

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.