bims-myxlip 2024-03-03 papers

Hum Pathol. 2024 Feb 22. pii: S0046-8177(24)00030-3. [Epub ahead of print]145 56-62

DDIT3-amplified or low-polysomic pleomorphic sarcomas without MDM2 amplification: Clinicopathological review and immunohistochemical profile of nine cases.

Several high-grade pleomorphic sarcoma cases that cannot be classified into any existing established categories have been reported. These cases were provisionally classified into undifferentiated pleomorphic sarcoma (UPS). Some dedifferentiated liposarcoma (DDLS) cases may also have been classified into the UPS category due to the absence of MDM2 amplification or an atypical lipomatous tumor/well-differentiated liposarcoma component. We retrieved and reviewed 77 high-grade pleomorphic sarcoma cases, initially diagnosed as UPS in 66 cases and DDLS in 11 cases. Fluorescence in situ hybridization (FISH) analyses of DDIT3 and MDM2 were performed for available cases. Of the cases successfully subjected to DDIT3 FISH (n = 56), nine (7 UPS and 2 DDLS) showed DDIT3 amplification but no MDM2 amplification. Two UPS cases showed both telomeric (5') and centromeric (3') amplification of DDIT3 or low polysomy of chromosome 12, whereas 5 UPS and 2 DDLS cases showed 5'-predominant DDIT3 amplification. Histopathologically, all cases showed UPS-like proliferation of atypical pleomorphic tumor cells. Immunohistochemically, only one case showed focal nuclear positivity for DDIT3, supporting the previous finding that DDIT3 expression was not correlated with DDIT3 amplification. All three cases with focal MDM2 expression involved 5'-predominant amplification, two of which showed DDLS-like histological features. The majority of cases (7/9) showed decreased expression in p53 staining, suggesting that DDIT3 amplification regulates the expression of TP53 like MDM2. From a clinicopathological perspective, we hypothesize that DDIT3-amplified sarcoma, especially with 5'-predominant amplification, can be reclassified out of the UPS category.

Keywords: 12q13; DDIT3 amplification; Dedifferentiated liposarcoma; MDM2 amplification; Undifferentiated pleomorphic sarcoma

DOI: https://doi.org/10.1016/j.humpath.2024.02.007

Ear Nose Throat J. 2024 Feb 29. 1455613241235499

Myxoid Liposarcoma of the Parotid Gland.

Sameh Mezri, Chaima Zitouni, Wadii Thabet, Chaima Ben Amar, Karima Tlili, Fethi Bougrine, Khemaies Akari.

Liposarcoma is extremely rare in the parotid gland. In this article, we report the case of an 87-year-old man who presented to our department with swelling in the left parotid region. Magnetic resonance imaging (MRI) revealed a tumor in the superficial lobe of the parotid gland. Total parotidectomy and ipsilateral lymph node dissection were performed. Histologic examination confirmed the diagnosis of myxoid liposarcoma of the parotid gland. On imaging, there was no evidence of nodal or distant metastasis. Radiation therapy was planned, but the patient refused to receive treatment. After a follow-up of 3 years, MRI showed no sign of tumor recurrence and the patient remained symptom-free. The case is original by the tumor's location. Only 8 cases of primary parotid liposarcoma have been reported in the literature. The purpose of this article was to discuss, through our case, clinical and anatomopathological features of parotid gland liposarcomas as well as its treatment options and prognosis.

Keywords: liposarcoma; parotid; prognosis; sarcomas; treatment

DOI: https://doi.org/10.1177/01455613241235499

Nat Cancer. 2024 Mar 01.

Sarcoma microenvironment cell states and ecosystems are associated with prognosis and predict response to immunotherapy.

Characterization of the diverse malignant and stromal cell states that make up soft tissue sarcomas and their correlation with patient outcomes has proven difficult using fixed clinical specimens. Here, we employed EcoTyper, a machine-learning framework, to identify the fundamental cell states and cellular ecosystems that make up sarcomas on a large scale using bulk transcriptomes with clinical annotations. We identified and validated 23 sarcoma-specific, transcriptionally defined cell states, many of which were highly prognostic of patient outcomes across independent datasets. We discovered three conserved cellular communities or ecotypes associated with underlying genomic alterations and distinct clinical outcomes. We show that one ecotype defined by tumor-associated macrophages and epithelial-like malignant cells predicts response to immune-checkpoint inhibition but not chemotherapy and validate our findings in an independent cohort. Our results may enable identification of patients with soft tissue sarcomas who could benefit from immunotherapy and help develop new therapeutic strategies.

DOI: https://doi.org/10.1038/s43018-024-00743-y

Semin Nucl Med. 2024 Feb 28. pii: S0001-2998(24)00005-9. [Epub ahead of print]

PET/CT and PET/MR in Soft Tissue Sarcoma: An Update.

Hedieh Khalatbari, Barry L Shulkin, Marguerite T Parisi.

Soft tissue sarcomas account for 6%-8% of pediatric cancers. The rhabdomyosarcoma family is the most frequent soft tissue sarcoma in this age group accounting for 3% of pediatric cancers. Rhabdomyosarcomas are high-grade tumors with a high propensity to metastasize. The risk-adapted, multimodal therapeutic approach for rhabdomyosarcomas incorporates a combination of surgery, radiotherapy, and multi-agent cytotoxic chemotherapy. Soft tissue sarcomas other than rhabdomyosarcoma account for 3%-4% of pediatric cancers. The nonrhabdomyosarcoma soft tissue sarcomas include both low-grade and high-grade tumors. While surgery is the mainstay of therapy in most non-rhabdomyosarcoma soft tissue sarcomas, many cases require a multimodal therapeutic approach including radiotherapy and chemotherapy. In North America, most pediatric patients with soft tissue sarcomas are treated in Children's Oncology Group clinical trials. In this article, we will primarily focus on the staging, risk stratification, imaging recommendations, and interpretations in accordance with the Children's Oncology Group trials. We will review the results and recommendations of International Soft Tissue Sarcoma Database Consortium and European trials in relevant sections where they provide complementary guidelines.

DOI: https://doi.org/10.1053/j.semnuclmed.2024.01.005