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

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.

Primary hepatic liposarcoma is an extremely rare malignant tumour derived from adipocytes and is part of the group of mesenchymal tumours. We present the case of a 43-year-old Hispanic male patient with a pleomorphic hepatic liposarcoma and absence of MDM2 gene amplification. Two years and six months after surgery, the patient is asymptomatic. The present case is the first report of this entity with positive immunohistochemical testing for p16, p53, S100, vimentin and absence of MDM2 gene amplification.

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.

Head and neck primary soft tissue sarcoma is a rare adult connective tissue malignant tumor derived from mesenchymal tissue, which can occur in the paranasal sinuses, throat or neck space.The clinical manifestations are local spread masses in the head and neck or difficulty breathing, swallowing, etc al. MRI and enhanced CT examination are the most commonly used to diagnose such diseases. Pathological diagnosis requires immunohistochemistry combined with FISH to detect MDM2 and CDK4. In this report，two cases of primary soft tissue sarcoma were reported,one is parotid high-differentiated liposarcoma and the other is laryngeal dedifferentiated leiomyosarcoma, introducing the characteristics diagnosis and treatment, and reviewing the relevant literature.
摘要: 头颈部原发性软组织肉瘤是成人罕见的来源于间叶组织的结缔组织恶性肿瘤，可发生于鼻旁窦、咽喉或颈部间隙内，临床表现为头颈部局部蔓延性肿物或呼吸、吞咽困难等，MRI和增强CT检查为此类疾病最常用的检查手段，病理诊断需要免疫组织化学结合荧光原位杂交技术（FISH）检测MDM2和CDK4作为常规辅助手段，本文分别报道腮腺高分化脂肪肉瘤和喉去分化平滑肌肉瘤各1例，介绍其病例特点和诊治经过，并对该病例进行相关文献复习。.

暂无摘要。

BACKGROUND: Germline TP53 mutations have been frequently reported in patients with Li-Fraumeni syndrome (LFS), resulting in a predisposition to various malignancies. Mutations other than germline TP53 mutations can also cause LFS-associated malignancies, but their details remain unclear. We describe a novel c-myc amplification in a unique liposarcoma in a patient with LFS.
METHODS: A female patient with LFS developed breast cancer twice at the age of thirty; both were invasive ductal carcinomas harboring HER2 amplifications. Computed tomography revealed an anterior mediastinal mass, which was surgically resected. Histological analysis revealed three different lesions corresponding to myxoid liposarcoma-, pleomorphic liposarcoma-, and well-differentiated liposarcoma-like lesions. Fluorescence in-situ hybridization (FISH) analysis did not detect MDM2 amplification, Rb1 deletion, break apart signals of EWS, FUS, DDIT3, or c-myc, or c-myc-IGH fusion signals, but it did detect more c-myc signals. Further FISH analysis and comprehensive genomic profiling revealed c-myc amplification. We considered two differential diagnoses, dedifferentiated liposarcoma lacking MDM2 amplification and myxoid pleomorphic liposarcoma (MPLPS), and determined that this case is most likely MPLPS. However, definite diagnosis could not be made because a clear-cut differentiation of the case from liposarcomas was not possible.
CONCLUSIONS: A previous study demonstrated that c-myc amplification could not be detected in various liposarcomas, but the present unique liposarcoma showed c-myc amplification, so the c-myc amplification may indicate that the present liposarcoma is an LFS-related tumor. The present case further clarifies the pathological features of MPLPS and LFS-related liposarcomas by broadening their histopathological and genetic diversities.

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OBJECTIVE: The current research was conducted to study the association between the SNP309 and del1518 polymorphisms with the breast cancer in the patients with the Kurdish ethnic background from western Iran. Also, a systematic review of the relevant case-control studies on the MDM2 polymorphisms in the patients with breast cancer was performed.
METHODS: Two mL of peripheral blood was taken from 100 patients with breast cancer and 100 healthy individuals. The frequencies of MDM2 SNP309 and del1518 genotypes and alleles were determined using the PCR-RFLP and PCR methods, respectively.
RESULTS: The frequency of the TT, TG, and GG of MDM2-SNP309 genotypes in the patients was obtained as 23%, 52%, and 25%, and they were equal to 22%, 40%, and 38% in the control group, respectively. Also, considering the MDM2-del1518 polymorphism, the frequencies of ins/ins, ins/del, and del/del genotypes were equal to 52%, 41%, and 7% in the breast cancer group and they were equal to 62, 30, and 8% in the control group, respectively. Analysis of the results indicated that the GG genotype plays a protective role for the breast cancer in the recessive model (GG vs TT + TG) of SNP309 (χ2  = 3.916, P = .048, and OR = 0.54).
CONCLUSIONS: Our findings revealed that the GG genotype of MDM2-SNP309 can play a protective role in the breast cancer disease. Also, our systematic review indicated that the SNP309, SNP285, and del1518 of MDM2 gene in different populations mostly did not have a significant association with the risk of breast cancer.

Primary liposarcoma of thymic stroma is an exceptionally rare tumor. Histological findings are often definitive for diagnosis, however due to the variability of nuclear atypia and the overlapping with other adipocytic tumors, ancillary techniques are helpful as confirmatory tools. Currently, Fluorescent in situ hybridization for MDM2 is the gold standard for diagnosis of well-differentiated and dedifferentiated liposarcomas, however a panel of immunohistochemical stainings, including MDM2, CDK4 and p16 is available as alternative method, helping to distinguish liposarcoma from its benign counterpart lipoma, especially in borderline cases. We describe the case of a young female diagnosed with a well-differentiated lipomatous tumor primary of thymic stroma with near cut-off result for MDM2-FISHand positive immunohistochemical staining for the panel described above. We discuss the challenges in the diagnosis of this rare entity andpresent an updated literature review.