Lipoma Research Articles

Case report: a rare clinical presentation of a difficult diagnosis of dedifferentiated liposarcoma showing leiomyosarcoma phenotype in the ileocecal region

Dedifferentiated liposarcoma is a malignant lipomatous tumor that rarely occurs in the gastrointestinal tract, including the ileocecal region. In this case, computed tomography and magnetic resonance imaging showed no fatty mass located in the mesenteric or submucosal lesion, and positron emission tomography–computed tomography showed a high maximum standardized uptake value, collectively indicating the gastrointestinal stroma tumor and lymphoma. The pathological findings resemble leiomyosarcoma; the immunohistochemistry findings including mouse double minute 2 homolog and cyclin D-dependent kinase-4 and amplification of mouse double minute 2 homolog in fluorescence in situ hybridization just favored the diagnosis of dedifferentiated liposarcoma with leiomyosarcoma phenotype and not leiomyosarcoma. Recently, a new inhibitor for mouse double minute 2 homolog and cyclin D-dependent kinase-4 has been developed, and clinical trials for dedifferentiated liposarcoma are currently ongoing. This could change the treatment strategy drastically compared with other soft tissue sarcomas. Hence, a correct diagnosis of dedifferentiated liposarcoma is required.

Lipomatous Neoplasms of Soft Tissue: A Contemporary Review.

This review summarizes the clinicopathologic features of various lipomatous tumors of soft tissue and addresses some recent conceptual issues relating to adipocytic neoplasms, such as atypical spindle cell/pleomorphic lipomatous tumor and myxoid pleomorphic liposarcoma, and provides an update on the molecular aspects of these tumors. Recent advances in cytogenetic characterization and classification of lipomatous tumors are reviewed, and the genetic importance of distinct chromosomal aberrations are briefly discussed.

MDM2 Testing In Lipomatous Tumors: An Institutional Experience with 1,161 Neoplasms

Abstract Introduction/Objective Amplifications of the MDM2 gene is a well-recognized central molecular event in atypical lipomatous tumors, well-differentiated liposarcomas, and dedifferentiated liposarcomas. However, given the fact that most adipocytic neoplasms are benign, the specific testing approaches that will maximize the detection of MDM2 amplified tumors in an accurate and cost-efficient manner remains unclear. The purpose of this study is to present our experience with MDM2 testing by FISH in a large cohort of lipomatous neoplasms. Methods/Case Report The pathologic database of an academic medical center was queried for all lipomatous tumors as well as all tumors for which MDM2 testing was performed during a three-year period. At our center, MDM2 testing for well differentiated adipocytic neoplasms is triggered by the so-called “traditional criteria”: a deep tumor and/or tumor size >10 cm and/or recurrence. We also take an expanded approach for a variety of indications that may include equivocal atypia or clinical/imaging concern, among others. Testing is also performed on overt malignancies for which dedifferentiated liposarcoma is a plausible consideration after review of morphologic features. Clinicopathologic data, including patient age of diagnosis, tumor size, depth of tumor, results from MDM2 testing [when performed], anatomic location(s) and recurrence [where applicable], were collected for each patient. Results (if a Case Study enter NA) 1161 cases were assessed, 456 of whom underwent MDM2 testing, and 108 of which were ultimately classified as MDM2 amplified. Standardized bivariable comparisons found that a deep tumor location (p=0.0014) and older age (p=0.0002), but not tumor size at the >10 cm cut off were associated with MDM2 positivity. However, a logistic regression model showed that neither size, depth or age were significantly associated with MDM2 positivity. Among the MDM2-positive cohort, 91% had tumor sizes <10 cm, 14% were superficial, 23% were non-recurrent and 15% were less than the median cohort patient age of 58 years. If the aforementioned “traditional criteria” were used as the sole basis for MDM2 testing, 50 (46.29%) of the 108 cases that were ultimately classified as MDM2 positive would not have been tested. Conclusion Our findings suggest that a strict adherence to “traditional criteria” may result in a significant subset of MDM2 positive tumors not being tested in lipomatous tumors. A more expansive approach that incorporates additional indications for testing, should be evaluated.

A Case of Recurrent Atypical Lipomatous Tumor.

A Case of Recurrent Atypical Lipomatous Tumor.

Characterizing the Transformation and Diagnosis of Atypical Lipomatous Tumor to Dedifferentiated Liposarcoma: Single Institutional Outcomes.

Atypical lipomatous tumor (ALT) in the extremities is a locally aggressive adipocytic tumor with the potential risk of transformation into dedifferentiated liposarcoma (DDLS). Studies seldom differentiate whether DDLS was diagnosed on initial biopsy, final resected specimen, or subsequent recurrence. Our study seeks to characterize how and when patients received their ALT or DDLS diagnoses to better understand the relationship between the two neoplasms. We performed a retrospective review of patients diagnosed with ALT or DDLS of the extremities. Clinical characteristics, including the method of diagnosis of an ALT or DDLS, time between diagnoses, and tumor recurrence was recorded. Univariate/multivariate analysis was performed to identify risk factors. Forty-five patients were diagnosed with ALT after core needle biopsy (CNB) and 41 of them received marginal en bloc excision. Three (7.3%) of these patients had a heterogeneous tumor on final resection, pathology revealed both ALT and DDLS. Four patients (8.2%) were diagnosed with DDLS from CNB and received negative margin en bloc excision. One of these tumors was identified as heterogeneous ALT/DDLS after resection. Fifty-three patients received marginal en bloc resection without CNB after a benign lipomatous mass was suspected on CT/MRI. Among these, one (1.9%) had a tumor with a heterogeneous composition of both ALT and DDLS on pathology. There were 11 (11.7%) ALT recurrences and 1 (1.0%) DDLS recurrence after ALT resection. Obtaining a proper diagnosis whether ALT or DDLS is critical. Our cohort found that amongst those concerning lipomatous lesions biopsied, 7.84% will show biopsy proven DDLS. Additionally, 6.67% of the biopsies will be false negatives and show DDLS on final pathology. Furthermore, our local recurrence for ALT was 11.7% recurring as ALT and 1.0% recurring as DDLS.

8571 Co existence of aldosterone excess in adrenal myelolipomas

Abstract Disclosure: I. Mishra: None. A. Baliarsinha: None. Co existence of aldosterone excess in adrenal myelolipomas Abstract: Adrenal myelolipomas are benign, lipomatous tumours, most of which present as adrenal incidentalomas.Co existence of cortisol excess states and aldosterone producing carcinomas is reported with adrenal myelolipomas,however isolated aldosterone excess without imaging features of adrenal malignancy is rare.We describe 3 cases presenting for evaluation of hyperaldosteronism but with imaging features consistent with myelolipomas. Case 1;58 year female presented with hypertension and spontaneous hypokalemia.On evaluation BMI was 25.3kg/m2,Gr 2 hypertensive retinopathy with systemic examination within normal limits.Biochemical evaluation revealed; Pl.Aldo(ng/dl)32.5; PRA(ng/ml/hr)0.54; ARR 60.5; SIT Pl.Aldo(ng/ml)27.8; AVS- not done; IMAGING(CT) Left adrenal fat attenuating 16×13mm lesion baseline HU < - 20 ?adrenal myelolipoma; Mx Left adrenalectomy H/P Adrenocortical hyperplasia;post op-resolution of hypokalemia with persistence of hypertension controlled with decreased number of drugs. Case 2;38 year male presented with resistant hypertension ,cerebro vascular accident,right hemiparesis and diuretic induced hypokalemia.On evaluation BMI was 31 kg/m2,Gr 1 hypertensive retinopathy with right hemiparesis.Biochemical evaluation revealed; Pl.Aldo(ng/dl)12.3; PRA(ng/ml/hr) 0.82; ARR 15; SIT Pl.Aldo(ng/ml)7.79; AVS- not done; IMAGING(CT) Left adrenal fat attenuating 28×30mmlesion baseline HU < -20? adrenal myelolipoma; Mx Left adrenalectomy H/P adrenal myelolipoma;post op-resolution of hypokalemia ,recovery of weakness and normalization of hypertension without drugs. Case 3;49 year male presented with hypertension ,incidental detection of adrenal lesion on ultrasound for pain abdomen and normokalemia.On evaluation BMI was 27 kg/m2,no significant findings on general examination with systemic examination within normal limits. Biochemical evaluation revealed; Pl.Aldo(ng/dl)12.2; PRA(ng/ml/hr) 0.58; ARR 20.2; SIT Pl.Aldo(ng/ml)11; AVS- not done; IMAGING(CT) Left adrenal fat attenuating 22x 26 mm lesion baseline HU < -20? adrenal myelolipoma; Mx drug therapy for hypertension due to refusal for surgical therapy with monitoring of blood pressure. In surgically treated adrenal myelolipomas, adrenal hormone excess is reported in 5-6% of cases, with autonomous cortisol secretion being most common .Even on the background of CT findings consistent with myelolipomas, patients fulfilling the screening and confirmatory criterias of primary hyperaldosteronism must be subjected to apt therapeutic modality.The presence of aldosterone clusters with excessive aldosterone synthase activity in these lesions could be reason for occurrence of primary hyperaldosteronism in myelolipomas. Presentation: 6/3/2024

Liposarcoma del cordón espermático

Introduction: liposarcoma of the spermatic cord (LSC) is a rare condition and accounts for about 3 to 7% of all paratesticular sarcomas. A case is presented in an 80-year-old patient who consulted for a left inguinoscrotal painless swelling, that had been present for several years. Physical examination revealed a soft left hemiscrotal tumor that appeared not to be adherent to the testicle. Ultrasonography showed a solid, heterogeneous hyperschoic paratesticular mass with central calcifications and peripheral hypervascularity. During surgery, a diffuse lipomatous tumor was found in the spermatic cord on the superior pole of the left testicle, separated from it. Anatomopathological examination revealed a well-differentiated liposarcoma of the spermatic cord. Discussion: this neoplasm features a slow-growing palpable paratesticular mass. This site of occurrence is rare and represents 7 to 10% of all scrotal tumors. Imaging differentiation between LSC and benign lesions is sometimes challenging. Surgical treatment should include radical orchiectomy wide local excision, and spermatic cord and inguinal ring surrounding soft tissue resection. Conclusion: spermatic cord liposarcoma is a rare and unusual mesenchymal tumor and should be considered among the differential diagnoses of scrotal tumors.

Multi-center external validation of an automated method segmenting and differentiating atypical lipomatous tumors from lipomas using radiomics and deep-learning on MRI

As differentiating between lipomas and atypical lipomatous tumors (ALTs) based on imaging is challenging and requires biopsies, radiomics has been proposed to aid the diagnosis. This study aimed to externally and prospectively validate a radiomics model differentiating between lipomas and ALTs on MRI in three large, multi-center cohorts, and extend it with automatic and minimally interactive segmentation methods to increase clinical feasibility. Three study cohorts were formed, two for external validation containing data from medical centers in the United States (US) collected from 2008 until 2018 and the United Kingdom (UK) collected from 2011 until 2017, and one for prospective validation consisting of data collected from 2020 until 2021 in the Netherlands. Patient characteristics, MDM2 amplification status, and MRI scans were collected. An automatic segmentation method was developed to segment all tumors on T1-weighted MRI scans of the validation cohorts. Segmentations were subsequently quality scored. In case of insufficient quality, an interactive segmentation method was used. Radiomics performance was evaluated for all cohorts and compared to two radiologists. The validation cohorts included 150 (54% ALT), 208 (37% ALT), and 86 patients (28% ALT) from the US, UK and NL. Of the 444 cases, 78% were automatically segmented. For 22%, interactive segmentation was necessary due to insufficient quality, with only 3% of all patients requiring manual adjustment. External validation resulted in an AUC of 0.74 (95% CI: 0.66, 0.82) in US data and 0.86 (0.80, 0.92) in UK data. Prospective validation resulted in an AUC of 0.89 (0.83, 0.96). The radiomics model performed similar to the two radiologists (US: 0.79 and 0.76, UK: 0.86 and 0.86, NL: 0.82 and 0.85). The radiomics model extended with automatic and minimally interactive segmentation methods accurately differentiated between lipomas and ALTs in two large, multi-center external cohorts, and in prospective validation, performing similar to expert radiologists, possibly limiting the need for invasive diagnostics. Hanarth fonds.

Atypical Spindle Cell/Pleomorphic Lipomatous Tumor: A Review and Update.

Atypical spindle cell/pleomorphic lipomatous tumor (ASCPLT) is a rare and recently described adipocytic neoplasm that primarily occurs in the subcutis of the limbs and limb girdles, particularly of middle-aged adults. It has locally recurrent potential if incompletely excised but no risk for distant metastasis. ASCPLT is histologically similar to spindle cell/pleomorphic lipoma and atypical lipomatous tumor and shows a mixture of atypical spindle cells, adipocytes, lipoblasts, floret-like multinucleated giant cells, and/or pleomorphic cells. It has been recently recognized that ASCPLT can undergo sarcomatous transformation. However, the biological significance of morphological sarcomatous transformation in ASCPLT remains uncertain. Immunohistochemically, the tumor cells show variable expression of CD34, S-100 protein, and desmin. Loss of nuclear Rb expression is observed in the majority of cases. ASCPLT lacks MDM2 gene amplification but can show RB1 gene deletion in a significant subset of cases. Complete surgical excision is the treatment of choice. This review provides an overview of the current knowledge on the clinicoradiological features, pathogenesis, histopathology, and treatment of ASCPLT. In addition, we will discuss the differential diagnosis of this new entity.

Growth Rate and Outcomes in Locally Recurrent Extremity and Truncal Soft Tissue Sarcoma.

Improved prognostic tools are needed for patients with locally recurrent extremity or truncal soft tissue sarcoma (STS). To examine the association between average local recurrence (LR) growth rate and outcomes following resection of locally recurrent extremity or truncal STS. This retrospective cohort study used a prospectively maintained database from a single high-volume tertiary sarcoma referral center in the US to identify patients 16 years of age or older who underwent repeat resection of a locally recurrent extremity or truncal STS between July 1, 1982, and December 31, 2021. Patients with atypical lipomatous tumors, desmoid tumors, dermatofibrosarcoma protuberans, angiosarcomas, and prior or synchronous distant recurrence were excluded. Data were analyzed from November 1, 2022, to June 17, 2024. Average LR growth rate, defined as the sum of recurrent tumor maximal diameters divided by the disease-free interval after index operation. The primary outcomes were cumulative incidences of disease-specific death (DSD), with death from other causes as a competing risk, and second LR, with death from any cause as a competing risk. The study cohort included 253 patients (median [IQR] age, 64 [51-73] years; 140 [55.3%] male). The 5-year cumulative incidence of DSD after repeat resection was 29%. Multivariable analysis indicated that LR growth rate (hazard ratio [HR], 1.12 [95% CI, 1.08-1.18]; P < .001), younger age (HR, 0.98 [95% CI, 0.97-0.99]; P = .002), R1 or R2 margins (HR, 1.71 [95% CI, 1.03-2.84]; P = .04), high LR grade (HR, 2.90 [95% CI, 1.17-7.20]; P = .02), and multifocality (HR, 2.92 [95% CI, 1.70-5.00]; P < .001) were independently associated with higher incidence of DSD. Using the minimum P value method, the optimal cutoff for growth rate was found to be 0.68 cm/mo. Patients with values above this cutoff had higher 5-year incidences of DSD following repeat resection (63% vs 19%; permutation test P < .001) and higher amputation rates (19% vs 7%; P = .008). Only R1 margins were independently associated with higher incidence of second LR (HR, 1.81 [95% CI, 1.19-2.78]; P = .006). In this cohort study of patients undergoing resection of a locally recurrent extremity or truncal STS, LR growth rate was independently associated with DSD. These findings suggest that patients with growth rates higher than 0.68 cm/mo who undergo LR resection may have high disease-specific mortality and amputation rates and should be considered for perioperative systemic therapy.

Oncocytic Lipoadenoma of the Parotid Gland against a Background of Multifocal Oncocytic Hyperplasia: Report of a Rare Case

ABSTRACT Oncocytic lipoadenoma is an extremely rare benign salivary gland tumor with only few cases reported in the literature. We herein report a case of oncocytic lipoadenoma originating in the parotid gland of a 65-year-old man. The tumor presented as a slowly growing asymptomatic right-sided parotid gland mass. On MRI, right parotid showed a 40 × 32 × 20 mm well-encapsulated, neoplastic mass in the superficial lobe. On core biopsy, differentials considered were nodular oncocytosis and oncocytoma. Subsequently, superficial parotidectomy was performed. The resected tumor was encapsulated, yellowish brown, and homogenous. Microscopically, it was composed of oncocytoma-like epithelial component admixed with mature adipocytes, each contributing to 50% of the mass. Adjacent salivary gland showed multiple foci of oncocytosis. Differential diagnosis includes lipomatous tumors as well as neoplastic and non-neoplastic oncocytic lesions of the salivary gland. The present case of oncocytic lipoadenoma against a background of multifocal oncocytic hyperplasia has been reported for its rarity.

Diagnostic Accuracy of Immunohistochemical Expression of p16, MDM2, and CDK4 in Well-Differentiated and De-Differentiated Liposarcoma in MDM2 Fluorescent in situ Hybridisation Confirmed Cases.

To establish the diagnostic utility of immunohistochemistry markers p16 along with MDM2 and CDK-4 in confirming the diagnosis of well-differentiated and de-differentiated liposarcoma while taking Fluorescent in situ Hybridisation (FISH) as a gold standard. A cross-sectional study. Place and Duration of the Study: Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from 30th January 2022 to 30th June 2023. A standard panel of three immunohistochemistry markers p16, MDM2, and CDK4 were applied to 36 cases of atypical lipomatous tumours, well-differentiated liposarcoma (WDLPS), and de-differentiated liposarcoma (DDLPS), on which the gold standard FISH was already performed. The sample size was calculated with the help of a WHO calculator taking prevalence 1-2% in Pakistani population. Qualitative variables such as gender and site of tumour were presented by calculating frequency and percentages and comparison of Immunohistochemistry results with FISH was done by using a 2x2 table. The sensitivity and specificity of this triple marker panel for detecting WDLPS/DDLPS were 43.47% and 15.38%, respectively. The sensitivity and specificity of CDK4 for detecting WDLPS / DDLPS were 82.6% and 15.4%, those of MDM2 were 73.9% and 61.5 %, and those of p16 were 60.9% and 53.8%, respectively. Among all three markers, CDK4 was the most sensitive and MDM2 was the most specific marker for detecting WDLPS-DDLPS. It also showed that a combination of these three markers improves the diagnostic credibility of the immunohistochemistry in diagnosing DDLPS and WDLPS but FISH is the most reliable and confirmatory method. De-differentiated liposarcoma, Well-differentiated liposarcoma, P16, CDK4, MDM2.

Diagnostic performance of fine-needle aspiration in soft tissue tumors: Application of the World Health Organization System for Reporting Soft Tissue Cytopathology and risk of malignancy assessment.

Recently, a new World Health Organization Reporting System for Soft Tissue Cytopathology (WHO System) was introduced. To analyze the value of this system, routine fine-needle aspiration soft tissue tumor (STT) cases were reviewed. Cytology samples of STTs collected between 1954 and 2022 at the Institut Curie were used (2214 cases, including 1376 primary tumors). All specimens were classified according to the predominant cytomorphological pattern and the WHO System. The diagnostic accuracy and risk of malignancy (ROM) in each category were calculated. Final diagnoses revealed 1236 malignancies and 978 benign or low-risk tumors. The original cytological evaluation led to 21 false-negative results (0.85%) and 29 false-positive results (1.17%). Sensitivity, specificity, positive predictive value, and negative predictive value were 98.3%, 92.1%, 97.5%, and 94.2%, respectively. Overall diagnostic accuracy was 94.2%. The ROM calculated according to the WHO System was 29.87%, 2.49%, 39.62%, 51.43%, 68.42%, and 97.69% in the nondiagnostic, benign, atypical, soft tissue neoplasm of uncertain malignant potential, suspicious for malignancy, and malignant categories, respectively; however, it varied broadly depending on the morphological pattern (62.78% in spindle cell tumors, 84.58% in myxoid tumors, 3.00% in lipomatous tumors, 78.15% in epithelioid tumors, 94.26% in pleomorphic tumors, and 100% in round cell tumors). Cytology of STTs is a powerful diagnostic method. Some cytological patterns overlap in different morphological groups, and the possibility of false-negative and false-positive diagnoses may persist. This analysis evidenced utility of the WHO System, especially when combined with morphological pattern assessment. Subclassification in particular diagnostic categories allowed for calculation of the ROM, which is crucial for optimal patient management.

Giant Atypical Spindle Cell Lipomatous Tumor of Retroperitoneal Origin Presenting with Lung Metastasis and Extension to the Thigh: A Case Report with Literature Review

AbstractRetroperitoneal liposarcomas are rare, and their variants, atypical spindle cell lipomatous tumor (ASCLT), are rarer. Though ASCLTs are benign, they have high recurrence despite complete surgical excision. We present a rare case of a 22-year-old male presented with insidious-onset, and gradually progressive swelling over left inguinofemoral, and iliac fossa region. Also, the patients had a history of weight loss, pricking-type pain radiating to left lower limb, and breathlessness on exertion. Contrast-enhanced computed tomography (CECT) abdomen revealed a large well-defined heterogeneously enhancing soft mass located in pelvis, and involving left-sided iliopsoas muscle suggestive of retroperitoneal soft tissue sarcoma and CECT thorax showed metastasis. The CT-guided core biopsy led to the definitive diagnosis of low-grade ASCLT. Subsequently, the patient was initiated on concurrent neoadjuvant chemoradiotherapy followed by complete surgical excision. The findings in this report make it critical to enhance our understanding of this rare tumor, with surgery being the best treatment option.

A rare case report of inverse sciatic hernia unveiling as a lipoma

Abstract When a swelling arising in the gluteal region herniates into the pelvic cavity through the sciatic foramen, it is referred to as inverse or reverse sciatic hernia and is a rare occurrence. We present the case of a 62-year-old female who presented with swelling in the left gluteal region with features of sciatica and abdominal pain. Magnetic resonance imaging showed 27 cm × 22 cm × 9 cm soft tissue swelling arising from the gluteal region and inversely herniating into the pelvic cavity through the sciatic foramen. We were successful in delivering the tumor through a gluteal approach. Lipomatous tumors presenting as inverse sciatic hernia are a rare event.

Epidemiología de los tumores musculoesqueléticos en una unidad de referencia

ObjectiveThe objective of this study was to perform an epidemiological analysis of patients presented to the Musculoskeletal Tumors Committee of a reference hospital. Material and methodA retrospective analysis of patients with sarcomas treated in a reference Sarcoma Unit between 2009 and 2022 was carried out. ResultsA total of 1978 patients were analyzed, of which 1477 (74.67%) were diagnosed as sarcomas. They were divided into 446 (30.20%) bone tumors and 1.031 (69.80%) soft tissue tumors. The most common benign bone tumor was enchondroma (27.23%), giant cell tumor (59.21%) was the most common tumor of intermediate malignancy and the malignant one was osteosarcoma (24.78%). The most frequently observed benign soft tissue tumor was lipoma (50.74%), the atypical lipomatous tumor (53.25%) was the most frequent tumor of intermediate malignancy and the malignant one was sarcoma of uncertain differentiation (38.10%). ConclusionOur study represents the first work on the epidemiology of sarcomas and other musculoskeletal tumors in our country, being very useful to adapt the resources destined for their diagnosis and treatment.

Characterizing the transformation and diagnosis of atypical lipomatous tumors to dedifferentiated liposarcoma: Single-institutional outcomes.

e23560 Background: Atypical lipomatous tumor (ALT) is a locally aggressive, benign adipocytic tissue mass with risk of transformation into dedifferentiated liposarcoma (DDLS), a mixed-grade, non-lipogenic tumor with increased risk for metastasis and mortality. Studies have evaluated the dedifferentiation rate of DDLS but seldom report the methodology of obtaining their diagnosis, which is crucial due to their heterogeneous architecture and relatively low core needle biopsy (CNB) accuracy. We included a longitudinal cohort of ALT/DDLS patients characterizing how and when patients received their diagnoses. Methods: 168 patients diagnosed with ALT-only (n = 129), DDLS-only (n = 22), or both (n = 17) were included. Among DDLS patients, the presence of a prior ALT diagnosis along with time between their ALT and DDLS diagnosis was measured. Histology, location, results, and methods of each diagnosis were recorded including, CNB, surgical resection, or both. Disease-specific survival (DSS) and recurrence free-survival (RFS) were calculated with univariate/multivariate analysis for risk factors. Results: Among patients who received a diagnosis with CNB consistent with ALT, 7 were subsequently diagnosed with DDLS after surgical resection, representing 4.8% of ALT patients. Mean time between diagnoses was 2.3 months (STD 2.0). 5 (3.4%) patients were diagnosed with a DDLS recurrence after initial ALT diagnosis confirmed with CNB and surgical resection. Median time between diagnoses was 37.0 months (IQR 16.0, 63.0). 5 (3.4%) had tumors with a heterogeneous composition on initial surgical resection, described as an ALT with dedifferentiated components. 22 DDLS patients had no prior ALT diagnosis. 9 were diagnosed from both CNB and surgical resection, and 13 were diagnosed from surgical resection directly after clinical suspicion and imaging concerning for sarcoma. DSS in the DDLS was significantly lower than ALT-only DSS (p &lt; 0.0001). There was no significant difference in RFS. Conclusions: DDLS may arise after an extended period of time after ALT resection or simultaneously with an ALT diagnosis. Due to its varied diagnostic timeline and appearance, caution is advised when evaluating and treating ALT. [Table: see text]

Challenge of Clinical Diagnosis and Treatment for Proteus Syndrome: A Case Report

Proteus syndrome (PS) is an extremely rare complex disorder, and caused by PS associated somatic mosaic AKT1 gene mutation. PS is characterized by progressive asymmetric, disproportionate overgrowth of patient’s skin, soft tissue, and bone of the different body parts since infant period. There is diversity in both clinical appearances, and with or without PS associated pathogenic genetic mutation situation can be existed for each patient. That caused clinical challenges for both accurate diagnosis and proper early treatment. We report a case of 17 years-old girl she presented with significant craniofacial dysmorphism, including prominent craniosynostosis and generalized skull bone sclerotic hyperostosis changes, hearing impairment after age of 3 years-old, progressive asymmetric overgrowth of the left lower limb with leg length discrepancy in childhood. Focal lipomatous tumors grow over the abdomen, left thigh and spinal deformity developed around teenage years. Hypermenorrhea with adenomyosis and ovarian cystadenoma lesions after menarche 12 years-old. Patient was fulfilled positive clinical criteria &gt; 17 points for clinical Proteus syndrome diagnosis, clinically strict met (mosaic distribution of lesions, sporadic occurrence, and progressive course) three general criteria for PS diagnosis. Although the whole exome sequencing test from affected thigh lipoma did not identify pathogenic/likely pathogenic variant AKT1, PTEN, PIK3CA gene. Whole genome sequencing test from affected cranial hyperostosis bone revealed MSH6 variant of uncertain significance (NM-000179.3: c.754T&gt;G) gene mutation. The patient has received surgical treated at three different medical centers in Taiwan for craniofacial dysmorphism, hearing loss, leg length discrepancy, and hypermenorrhea problems respectively. All clinical symptoms and problems with postoperative have partial relieved and improvement. Further more complicated surgery was necessary for her. Clinically we are challenged both for early confirming PS clinical diagnosis, and make the differential diagnosis from other clinical mimic overgrowth spectrum disorder.

Sclerosing well-differentiated liposarcoma: two diagnostically challenging mimicker cases and a literature review.

Liposarcoma is a malignant soft tissue tumor with several subtypes, the most common of which is well-differentiated liposarcoma (WDL) or atypical lipomatous tumor (ALT). WDL/ALTs are further divided into three histological subtypes, including lipoma-like, sclerosing, andinflammatory. While the majority of these tumors are predominantly fatty, the sclerosing variant demonstrates diverse histologic and radiographic characteristics, including variable amounts of fibrosis and fat. Because of this histological variability and relative rarity, the sclerosing WDL/ALT can present diagnostic dilemmas. We present two cases of sclerosing WDL/ALT, both of which demonstrated high degrees of fibrosis and a paucity of fat, mimicking desmoid fibromatosis and other fibrotic soft tissue tumors. Thus, it is important for radiologists to be aware of the subtypes of liposarcoma and their unique characteristics, and to consider sclerosing WDL/ALT in cases of fibrotic soft tissue tumors.

Spindle Cell Neoplasm

Spindle neoplasm an uncommon variant of benign lipomatous tumor, occurs mostly in the posterior neck or the shoulder  It contains well circumscribed &amp; no aggressive subcutaneous mass  Spindle cell neoplasm may be traced to epithelial, mesenchymal &amp; odontogenic  Latin (AE1/AE3, K1), K1, K18, and EMA appear to be the most sensitive/reliable epithelial spindle cell neoplasms.  Spindle cell neoplasms can be benign or malignant. Under a microscope, the neoplasm is composed of adipocytes flat cells and long, thin spindle cells. In a spindle cell lipoma, the adipocytes are surrounded by spindle cells.  The diagnosis test includes immunohistochemistry and fluorescence in site hybridization (FISH) to confirm the diagnosis and to include other tumors that can look like a spindle cell lipoma. If a spindle cell neoplasm is large or uncomfortable, it can be removed.