[Primary pulmonary myxoid sarcoma with EWSR1-CREB1 fusion]. / Pervichnaya legochnaya miksoidnaya sarkoma so sliyaniem genov EWSR1-CREB1.

Primary pulmonary myxoid sarcoma with EWSR1-CREB1 fusion is an extremely rare tumor. Its clinical manifestation is unspecific and only molecular genetic method can proof this diagnosis. This paper describes an unusual clinical presentation of primary pulmonary myxoid sarcoma in a 68-year-old patient with involvement of both lungs.

Sarcoma of the uterine cervix: experience of a single center.

OBJECTIVES: To investigate the clinicopathological characteristics and prognosis of patients with primary sarcoma of the uterine cervix. METHODS: We identified all patients with primary cervical sarcomas treated at our institution from 2002 to 2020 and analyzed the clinicopathological characteristics and prognosis. RESULTS: 34 patients were identified, 7 (20.6%) patients had leiomyosarcoma, 6 (17.6%) had carcinosarcoma, 5 (14.7%) had Ewing sarcoma, 4 (11.8%) had rhabdomyosarcoma, 4 (11.8%) had undifferentiated sarcoma, 2 (5.9%) had adenosarcoma, 2 (5.9%) had endometrial stromal sarcoma, 1 (2.9%) had dermatofibrosarcoma protuberans, 1 (2.9%) had alveolar soft tissue sarcoma and 2 (5.9%) had sarcoma not otherwise specified. The median age of the whole patients was 43.5 years (range, 13-63). The median age of patients with Ewing sarcoma or rhabdomyosarcoma was 22 years (range, 13-39) and 17 years (range, 13-36 years), respectively. The distribution by stage was: stage I in 21 (61.8%) patients, stage II in 4 (11.8%), stage III in 6 (17.6%) and stage IV in 3 (8.8%). Overall, 30 patients (88.2%) received surgical treatment. The median follow-up was 33.3 months (range 3.6-187.3 months). 11 patients died within 2 years after diagnosis, most of them were patients with carcinosarcoma or undifferentiated sarcoma (45.5%, 5/11). In the entire cohort, 2- and 5-year OS were 67.2% and 56.9%, respectively. 5-year OS was 25.0% for undifferentiated sarcoma, 50.0% for rhabdomyosarcoma, 50.0% for carcinosarcoma, 53.3% for Ewing sarcoma, 57.1% for leiomyosarcoma. CONCLUSION: Cervical sarcomas are rare neoplasms with multiple histological subtypes and follow an aggressive course. Prognosis may be associated with tumor histology and stage.

Extrapleural pneumonectomy for sarcoma: Outcomes of adult patients at a specialized center.

BACKGROUND: Extrapleural pneumonectomy (EPP) is a complex surgical procedure involving en-bloc resection of the parietal and visceral pleura, lung, pericardium, and ipsilateral diaphragm. Small case series of pleural-based sarcoma of predominantly pediatric patients suggest EPP may be a life-prolonging surgical option. We aimed to describe the characteristics and outcomes of adults who underwent EPP at a specialized sarcoma center. METHODS: Clinicopathologic variables, surgical details, and follow-up information were extracted for patients undergoing EPP for pleural-based sarcoma between August 2017 and December 2020. Primary outcomes were event-free survival (EFS) and overall survival (OS) from the date of EPP. Secondary outcomes were disease-free interval (DFI) prior to EPP, and early and late postoperative complications. RESULTS: Eight patients were identified, seven with soft tissue sarcoma and one with bone sarcoma. Patients had either localized disease with a primary thoracic sarcoma, sarcoma recurrent to the thorax, or de novo metastatic disease. All patients underwent resection of their pleural-based sarcoma by an experienced cardiothoracic surgeon, and some patients had pre or postoperative treatment. The perioperative morbidity was comparable with previously published reports of EPP performed in mesothelioma patients. At median follow-up of 22.5 months, median EFS was 6.0 months and OS was 20.7 months. Six patients (75%) had disease recurrence; five (62.5%) died of progressive disease. Two patients (25%) had not recurred: one died of a radiation-related esophageal rupture, and one was alive with no evidence of disease at 37.0 months. Characteristics of those with the longest EFS included low-grade histology and achieving a metabolic response to preoperative chemotherapy. CONCLUSIONS: In adults with pleural-based sarcoma, EPP is rarely curative but appears to be a feasible salvage procedure when performed at specialized centers. Patient selection is critical with strong consideration given to multimodal therapy to optimize patient outcomes. In the absence of a confirmed response to neoadjuvant treatment, long term survival is poor and EPP should not be recommended.

The diagnostic utility of cytology specimen in a case of EWSR1::NFATC2 sarcoma.

EWSR1::NFATC2 sarcoma, a rare round cell sarcoma constituting the majority of EWSR1::non-ETS sarcomas, has recently been defined in the latest WHO classification. To date, the cytological findings of EWSR1::NFATC2 sarcoma remain undocumented. We present the case of a 25-year-old man with a history of polyostotic fibrous dysplasia in the right leg, referred to our hospital with left thigh pain. Cytological findings included metachromasia, minimally pleomorphic round cells, and eosinophilic infiltration. There was no precursor fibrous dysplasia and the initial diagnosis was undifferentiated pleomorphic sarcoma. Following histologic review, we successfully performed immunocytochemistry and fluorescence in situ hybridization (FISH) on archival cytology specimens. The tumor cells were positive for NKX2-2, NKX3-1, and PAX7 and showed amplified 5' single signals of EWSR1 gene. Reverse transcriptase-polymerase chain reaction revealed an in-frame fusion of EWSR1 and NFATC2. This report describes the cytological features of EWSR1::NFATC2 sarcoma and highlights the diagnostic utility of archival cytology specimens.

Soft tissue tumours of the penis. The 30-year Istituto Nazionale Tumori di Milano experience.

Objective: Small series and individual cases of penile soft tissue tumours are reported in the literature: these are rare tumours that represent less than 5% of all penile tumours. Methods: Penile soft tissue tumours were collected from the archive of the Department of Pathology at the Istituto Nazionale dei Tumori of Milan between January 1990 and October 2021. All available medical records were retrieved and reviewed to obtain clinical information. Results: Our series refers to the 30-year experience of highlighting the heterogeneity in the presentation and microscopic features of these rare sarcomas. 18 penile soft tissue tumours are described, 4 benign and 14 malignant. The mean age at diagnosis was 58.2 years (range 24-96 years) and 53.6 years among malignancies (range 24-89). The most frequent histotype was Kaposi's sarcoma (nr = 4) and very unusual histotypes were observed, namely low-grade fibromyxoid sarcoma, synovial sarcoma, proximal type epithelioid sarcoma and the first reported case of dedifferentiated liposarcoma of the penis. Conclusions: Among sarcomas of the genitourinary tract, tumours of the soft tissues of the penis are the rarest. Penile sarcomas can present at a young age. Kaposi's sarcoma in HIV-negative patients has a favorable outcome, while deep sarcomas have an aggressive behavior and poor prognosis.

Opportunity in Complexity: Harnessing Molecular Biomarkers and Liquid Biopsies for Personalized Sarcoma Care.

Due to their rarity and complexity, sarcomas represent a substantial therapeutic challenge. However, the incredible diversity within and across sarcoma subtypes presents an opportunity for personalized care to maximize efficacy and limit toxicity. A deeper understanding of the molecular alterations that drive sarcoma development and treatment response has paved the way for molecular biomarkers to shape sarcoma treatment. Genetic, transcriptomic, and protein biomarkers have become critical tools for diagnosis, prognostication, and treatment selection in patients with sarcomas. In the future, emerging biomarkers like circulating tumor DNA analysis offer the potential to improve early detection, monitoring response to treatment, and identifying mechanisms of resistance to personalize sarcoma treatment. Here, we review the current state of molecular biomarkers for sarcomas and highlight opportunities and challenges for the implementation of new technologies in the future.

Primary adrenal epithelioid sarcoma (proximal type): a case report and literature review.

Primary adrenal epithelioid sarcoma is a rare lesion of the adrenal gland, and only seven cases have been reported in the domestic and international literature to date. We herein report a case involving a 65-year-old man with primary adrenal epithelioid sarcoma. After being admitted to the hospital with an adrenal mass found on physical examination, the patient underwent laparoscopic right adrenalectomy. Postoperative pathological findings indicated an epithelioid sarcoma (proximal type). Primary adrenal epithelioid sarcoma is a rare malignancy. Diagnosis is challenging and relies on histopathology and immunohistochemical staining.

Right Thigh Mass Metastasis from Lung Cancer Mimicking Primary Soft Tissue Sarcoma: A Case Report.

BACKGROUND Soft tissue metastases (STMs) are less common than bone metastases and sometimes misdiagnosed as primary soft tissue malignancies. Skin, lungs, and breast are the most common primary lesions of STMs and rarely the presenting symptoms. We present an STM from lung adenocarcinoma that became a presenting symptom in nonsmoking woman. CASE REPORT A 47-year-old woman presented to our hospital with a painful mass in her right thigh and weight loss of 10 kg for 4 months. Femoral radiograph revealed a lesion suggestive of bone sarcoma. However, magnetic resonance imaging (MRI) showed it was more likely a primary soft tissue sarcoma. A small mediastinal mass was noticed on preoperative chest radiograph, and the patient denied any symptoms except the mass in the right thigh. Our clinicopathological conference team decided to perform a biopsy of mediastinal and right thigh masses. Histopathology examinations confirmed the right thigh mass as soft tissue metastasis from mediastinal mass, confirmed as lung adenocarcinoma. We treated the patient with palliative care with zoledronic acid and gefitinib. At the 6-month follow-up, the patient's symptoms significantly improved, and MRI showed a marked size reduction. CONCLUSIONS Diagnosis of STM can be difficult when presenting as the primary manifestation. Failure to identify promptly can lead to rapid disease progression and unfavorable prognosis. Failure to diagnose primary malignancy during biopsy occurs in approximately 28% of cases. This report has the potential to facilitate the avoidance of unnecessary procedures and highlight the importance of using a multidisciplinary approach in managing cases with malignancy.

Update on Dosing and Fractionation for Neoadjuvant Radiotherapy for Localized Soft Tissue Sarcoma.

OPINION STATEMENT: Neoadjuvant radiotherapy (RT) over 5-6 weeks with daily doses of 1.8-2.0 Gy to a total dose of 50-50.4 Gy is standard of care for localized high-grade soft tissue sarcomas (STS) of the extremities and trunk wall. One exception is myxoid liposarcomas where the phase II DOREMY trial applying a preoperative dose of 36 Gy in 2 Gy fractions (3-4 weeks treatment) has achieved excellent local control rates of 100% after a median follow-up of 25 months.Hypofractionated preoperative RT has been investigated in a number of phase II single-arm studies suggesting that daily doses of 2.75-8 Gy over 1-3 weeks can achieve similar oncological outcomes to conventional neoadjuvant RT. Prospective data with direct head-to-head comparison to conventional neoadjuvant RT investigating oncological outcomes and toxicity profiles is eagerly awaited.For the entire group of retroperitoneal sarcomas, RT is not the standard of care. The randomized multi-center STRASS trial did not find a benefit in abdominal recurrence-free survival by the addition of preoperative RT. However, for the largest histological subgroup of well-differentiated and grades I and II dedifferentiated liposarcomas, the STRASS trial and the post-hoc propensity-matched STREXIT analysis have identified a possible benefit in survival by preoperative RT. These patients deserve to be informed about the pros and cons of preoperative RT while the longer follow-up data from the STRASS trial is awaited.

Assessment of medical students' knowledge of primary limb sarcomas.

INTRODUCTION: Typically, oncology is not a structured part of the curriculum in Brazilian medical schools. Furthermore, sarcomas, which are uncommon tumors, are seldom covered in depth. A lack of comprehensive education on sarcomas might result in medical professionals being ill-equipped to care for patients with this condition. OBJECTIVES: To assess medical students' understanding and awareness of sarcomas and the specific principles related to these tumors. MATERIALS AND METHODS: A quantitative, cross-sectional study was conducted using a questionnaire, applied to medical students, focusing on the epidemiology, pathophysiology, and treatments of bone and soft tissue sarcomas. In all tests, the significance level adopted was 5%. The SPSS version 25.0 software was used. RESULTS: Of the 825 questionnaires distributed, 325 were returned. Educational sessions on sarcomas did not appear to significantly improve the student's knowledge. Only 29.5% of students identified the lack of pain as an indicator of potential malignancy in soft tissue sarcomas, while 73.8% correctly recognized pain as a symptom of bone sarcomas. Limb amputation as the optimal surgical method for patient recovery was incorrectly reported by 39.1% of the sample. CONCLUSION: A great part of the surveyed population does not have adequate knowledge about the basic concepts associated with limb sarcomas. The minority of them are satisfied with the knowledge gained during their medical education about these tumors. Inadequate medical academic training may initially lead to the wrong clinical management of patients with bone and soft tissue tumor lesions. An educational effort is needed to enhance oncology education for medical students, especially concerning sarcomas.

Management of Uterine Fibroids and Sarcomas: The Palermo Position Paper.

BACKGROUND: Uterine fibroids are benign monoclonal tumors originating from the smooth muscle cells of the myometrium, constituting the most prevalent pathology within the female genital tract. Uterine sarcomas, although rare, still represent a diagnostic challenge and should be managed in centers with adequate expertise in gynecological oncology. OBJECTIVES: This article is aimed to summarize and discuss cutting-edge elements about the diagnosis and management of uterine fibroids and sarcomas. METHODS: This paper is a report of the lectures presented in an expert meeting about uterine fibroids and sarcomas held in Palermo in February 2023. OUTCOME: Overall, the combination of novel molecular pathways may help combine biomarkers and expert ultrasound for the differential diagnosis of uterine fibroids and sarcomas. On the one hand, molecular and cellular maps of uterine fibroids and matched myometrium may enhance our understanding of tumor development compared to histologic analysis and whole tissue transcriptomics, and support the development of minimally invasive treatment strategies; on the other hand, ultrasound imaging allows in most of the cases a proper mapping the fibroids and to differentiate between benign and malignant lesions, which need appropriate management. CONCLUSIONS AND OUTLOOK: The choice of uterine fibroid management, including pharmacological approaches, surgical treatment, or other strategies, such as high-intensity focused ultrasound (HIFU), should be carefully considered, taking into account the characteristics of the patient and reproductive prognosis.

Primary pulmonary myxoid sarcoma with EWSR1::CREB1 fusion: a literature review.

PURPOSE: This review primarily aims to review the epidemiology, clinical characteristics, imaging, pathology, immunohistochemistry, diagnosis, differential diagnosis, treatment, and prognosis of Primary pulmonary myxoid sarcoma (PPMS) with EWS RNA binding protein 1::cAMP response element binding protein 1 (EWSR1::CREB1) fusion. It provides reference for the diagnosis and treatment of this disease. METHODS: Retrospectively collected the literature about PPMS with EWSR1::CREB1 fusion, its clinical, radiology, histology, molecular characteristics and current treatment strategies were collated and analyzed. This review provides a detailed differential diagnosis of the disease. RESULTS: PPMS is an exceptionally rare, low-grade malignant tumor of the lung. This tumor commonly infiltrates lung tissue and develops within bronchial passages. It is identified by a genetic rearrangement involving the EWSR1 gene and a distinct chromosomal translocation t(2; 22)(q33; q12). Variants include EWSR1::CREB1 fusion and EWS RNA binding protein 1::activating transcription factors (EWSR1::ATF1) fusion. PPMS with EWSR1::CREB1 fusion is more prevalent among middle-aged individuals and affects both sexes almost equally. Clinical symptoms are relatively non-specific, primarily including cough, hemoptysis, and weight loss. Most patients undergo surgery and experience a favorable prognosis. Further research is required to validate the effectiveness of alternative treatments for PPMS with EWSR1::CREB1 fusion. CONCLUSION: EWSR1 rearrangement and EWSR1::CREB1 fusion are crucial genetic features of PPMS and serve as important diagnostic markers. Immunohistochemically, PPMS tests positive for EMA. In terms of treatment, surgery has been the primary approach in recent years. Therefore, the efficacy of other treatments still requires further investigation.

Primary soft tissue sarcoma breast with multiphenotypic differentiation.

Primary soft tissue sarcomas of the breast are rare aggressive neoplasms. These often are misdiagnosed with other more common neoplasms like fibroepithelial malignancies, namely phyllodes tumour and metaplastic carcinoma. Being uncommon, chances of being misdiagnosed are higher leading to early mortality. A multidisciplinary team incorporating surgery, pathology, chemotherapy and radiotherapy is required to formulate an approach to primary soft tissue sarcoma. Generally, these tumours may show single or dual phenotype; we present one rare case report showing multiphenotypic differentiation.

Diagnostic benefits of platelet-to-lymphocyte, neutrophil-to-lymphocyte, and albumin-to-globulin ratios in dogs with nasal cavity diseases.

BACKGROUND: A multimodal approach for diagnostic tests under anesthesia is required to diagnose nasal cavity pathology (NP) reliably in dogs. Blood test results may provide clues to the suspected NP. METHODS: This prospective blinded study assessed 72 dogs with chronic nasal discharge due to NPs, and 10 healthy dogs as the control group (CG). NPs were diagnosed using whole-body computed tomography (CT), upper airway endoscopy, examination of nasal mucosal swabs by bacterial and fungal culture, and histopathological examination of nasal mucosa biopsies. The exclusion criteria were the presence of any additional diseases or corticosteroid pre-treatment. In consideration of these exclusion criteria, 55 dogs entered the study. Dogs were classified into benign (benign tumors, idiopathic rhinitis (IR), and others) and malignant (carcinomas and sarcomas) NP groups. Blood count and blood chemistry tests were performed. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and albumin-to-globulin ratio (AGR) were calculated and compared. RESULTS: 25 dogs with malignant NP (13 and 12 with carcinomas and sarcomas, respectively) and 30 dogs with benign NP (seven with benign tumors,13 with IR, and 10 others) were included. In general, in dogs with NP there were only slight abnormalities in complete blood count. However, PLR was significantly higher in dogs with malignant NP (carcinoma and sarcoma) than in those with benign NP and in the CG. Compared with the CG, the NLR was significantly increased in all dogs with NP, and the AGR was mild but significantly lower, except in dogs with sarcomas and benign tumors. CONCLUSIONS: In dogs with nasal disease alone, there are usually no marked abnormalities in blood count. However, while mildly increased NLR and decreased AGR can be observed in almost all NPs, an increased PLR may indicate a malignant NP and can be used as an additional screening tool in dogs with nasal discharge due to nasal cavity pathology.

The utility of FISH analysis in the diagnosis of BCOR-rearranged sarcomas.

BACKGROUND: A BCL6 corepressor (BCOR) gene alteration is a genetic signature of rare subsets of sarcomas. The identification of this alteration has recently contributed to the definition of new entities in the current WHO (2020) classification of soft tissue and bone tumours. We retrospectively examined cases of BCOR-rearranged sarcoma (BRS) to assess the reliability of the BCOR FISH analysis using an IVD (in vitro diagnostic) probe. METHODS: We investigated and compared the molecular diagnostic strategies and features by collecting 17 data from patients with a BCOR gene rearrangement detected using quantitative-Reverse Transcription-Polymerase Chain Reaction (qRTPCR), Next-Generation Sequencing (NGS) and Fluorescence in situ hybridization (FISH). RESULTS: We describe fourteen BCOR::CCNB3 sarcomas, one spindle cell sarcoma with a novel BCOR::MAML1 fusion, one spindle cell sarcoma with a novel BCOR::AHR fusion, and one ossifying fibromyxoid tumour with a BCOR::ZC3H7B fusion. FISH analysis of all, except one, BCOR::CCNB3 sarcoma, showed a FISH break-apart pattern with mild signal separation. The MAML1::BCOR sarcoma showed large-space split signals, while in the two patients with AHR::BCOR and ZC3H7B::BCOR fusions, no BCOR rearrangement was observed using FISH. CONCLUSIONS: Our study indicates that BCOR FISH analysis using an IVD probe, may be useful to detect the presence of a BCOR rearrangement, including both translocations and inversions; however, negative results, in some cases, can occur.

Disparities in Survival and NCCN Guideline-Concordant Care in Patients With Extremity Soft Tissue Sarcoma.

BACKGROUND: Based on the NCCN Guidelines for Soft Tissue Sarcoma (STS), treatment of extremity STS (ESTS) includes radiation therapy (RT) and surgical resection for tumors that are high-grade and >5 cm. ​​The aim of this study was to describe the association between neighborhood socioeconomic status (nSES), concordance with NCCN Guidelines recommendations, and outcomes in patients with ESTS. METHODS: Patients with ESTS diagnosed from 2006 through 2018 were identified in SEER registries. The analytic cohort was restricted to patients with high-grade tumors >5 cm without nodal or distant metastases who received limb-sparing surgery. Patient demographics and tumor characteristics associated with receipt of RT were analyzed using adjusted regression analyses. Kaplan-Meier curves and adjusted accelerated failure time models were used to examine disparities in cancer-specific survival. RESULTS: Of 2,249 patients, 29.0% (n=648) received neoadjuvant RT, 49.7% (n=1,111) received adjuvant or intraoperative RT, and 21.3% (n=476) did not receive RT. In adjusted analyses, lower nSES was associated with lower likelihood of receiving RT (odds ratio, 0.70 [95% CI, 0.57-0.87]; P<.001). Low nSES was associated with worse cancer-specific survival (hazard ratio, 1.19 [95% CI, 1.01-1.40]; P=.04). Race and ethnicity were not significant predictors of receipt of RT or cancer-specific survival in the fully adjusted models. CONCLUSIONS: Patients from lower nSES areas were less likely to receive NCCN Guideline-recommended RT for their ESTS and had worse cancer-specific survival. Efforts to better define and resolve disparities in the treatment and survival of patients with ESTS are warranted.

A Rare Case of Pulmonary Artery Sarcoma.

Pulmonary artery sarcoma (PAS) is a rare and aggressive mesenchymal tumor with an overall poor prognosis1-5. Due to similar clinical and radiologic findings, PAS is often misdiagnosed as a pulmonary embolism (PE) frequently leading to prolonged anticoagulation therapy, which delays the correct diagnosis 1-3. By presenting this clinical case our objective is to emphasize characteristic CT findings that favour a neoplastic origin of a pulmonary intravascular filling defect. PET-CT and MRI have also an important potential role in its diagnosis and therapeutical management.

FGF23 Expression Is a Promising Immunohistochemical Diagnostic Marker for Undifferentiated Pleomorphic Sarcoma of Bone (UPSb).

Background: Undifferentiated pleomorphic sarcoma of bone (UPSb) is a rare primary bone sarcoma that lacks a specific line of differentiation. Distinguishing between UPSb and other malignant bone sarcomas, including dedifferentiated chondrosarcoma and osteosarcoma, is challenging due to their overlapping features. We have previously identified that UPSb tumours have elevated mRNA levels of Fibroblast Growth Factor 23 (FGF23) transcripts compared to other sarcomas including osteosarcoma. In the present study, we evaluated the specificity and practicality of FGF23 immunoreactivity as a specific diagnostic tool to differentiate UPSb tumours from osteosarcomas and dedifferentiated chondrosarcomas. Methods: A total of 10 UPSb, 10 osteosarcoma, and 10 dedifferentiated chondrosarcoma cases (all high-grade), were retrieved and immunohistochemistry for FGF23 was performed. Results: FGF23 protein was expressed at high levels in 80-90% of undifferentiated pleomorphic sarcoma of the bone cases, whereas it was expressed at significantly lower levels in dedifferentiated chondrosarcoma and osteosarcoma cases. A semiquantitative analysis, considering the intensity of immunoreactivity, confirmed significantly elevated FGF23 expression levels in UPSb tissues compared to those observed in osteosarcoma and dedifferentiated chondrosarcoma tissues. Conclusions: The results we present here suggest that FGF23 immunohistochemistry may be a useful tool to aid in differentiating UPSb from morphologically similar malignant bone sarcomas, especially in situations where sampling is restricted and there is limited clinical information available.

Pulmonary arterial sarcoma: A case report.

RATIONALE: Pulmonary artery sarcoma (PAS) is a rare malignant tumor primarily originating from the pulmonary artery's intima or subintima. Approximately one-third of cases are classified as undifferentiated type. Its clinical manifestations lack specificity, dyspnea is the main symptom but can also present with chest pain, cough, hemoptysis, and other discomforts, making it prone to misdiagnosis as pulmonary embolism (PE). PATIENT CONCERNS: A 50-year-old woman was admitted to the hospital with "dyspnea for more than 3 months, aggravated for 2 days," and computed tomography pulmonary angiography suggesting "bilateral multiple pulmonary embolisms." DIAGNOSES: The patient was initially misdiagnosed as PE, and was later definitively diagnosed as undifferentiated pleomorphic sarcoma of the pulmonary artery by pathologic biopsy. INTERVENTIONS AND OUTCOMES: The patient was initially treated with anticoagulant therapy, but her dyspnea was not relieved. After that, she underwent positron emission computed tomography (PET-CT) and other investigations, which suggested the possibility of PAS, and then she underwent pulmonary endarterectomy to remove the lesion, which relieved her symptoms and was advised to seek further medical attention from the Department of Oncology and Department of Radiotherapy. LESSONS: PAS can be easily misdiagnosed as PE. If a diagnosis of PE is made, but anticoagulation or even thrombolytic therapy proves ineffective, and there is no presence of PE causative factors such as deep vein thrombosis in the lower extremities, or D-dimer levels are not high, one should be cautious and consider the possibility of PAS.

Cytomorphology of metastatic dedifferentiated/undifferentiated melanoma to the gallbladder: A case report and review of literature.

Dedifferentiated/undifferentiated melanoma (DM/UM) is a distinct subtype of malignant melanoma that tends to lose all melanocytic markers of differentiation. DM/UM pose major diagnostic challenges as they could be easily confused with UM sarcoma or carcinoma, thus necessitating the use of molecular studies such as Next Generation Sequencing (NGS) for detecting melanoma-compatible mutations to confirm such diagnosis. The capability of performing NGS molecular studies on small biopsy material with confirmation of adequacy via rapid on-site evaluation (ROSE) has tremendous value in diagnosing DM/UM. Herein, we present the first reported case of metastatic DM/UM to the gall bladder arising in a 60-year-old female with a prior history of right knee melanoma. We also shed light on the cytomorphology of DM/UM, review the literature on such a challenging entity, and emphasize the crucial role of molecular testing in their diagnosis.