Ciliary body myxoid epithelioid sarcoma in a cat: a case report.

BACKGROUND: The majority of primary, intraocular tumors in cats originate from the uvea and include feline diffuse iris melanoma, lymphoma, and iridociliary epithelial adenoma or adenocarcinoma. In this case report, we describe for the first time the clinical, histological, and immunohistochemical findings of a rare myxoid intraocular neoplasm arising from the ciliary body in a cat. CASE PRESENTATION: A 14-year-old, female, spayed domestic shorthaired cat was presented for evaluation of discolouration of the right eye. Upon examination, a clear to light whitish-tan, bubble-shaped intraocular mass adherent to the inferior ciliary body and extending into the anterior chamber was noted. Within five weeks, the tumor was significantly larger and the eye had developed secondary glaucoma so was enucleated. Light microscopic examination of the globe revealed a multinodular, hypocellular neoplasm arising from the ciliary body composed of interwoven spindle cells embedded in abundant amounts of a lightly basophilic myxoid matrix. Neoplastic cells exhibited strong immunoreactivity for cytokeratin while also showing moderate to strong immunoreactivity to vimentin. A diagnosis was therefore made of an unusual intraocular myxoid epithelioid sarcoma arising from the ciliary body. CONCLUSIONS: Although apparently exceedingly rare, epithelioid myxosarcoma should be included as a differential diagnosis for intraocular tumors in cats and they represent a clinical, histologic, and immunohistochemical diagnostic challenge. Early surgical intervention should be considered to prevent local invasion and ascension to the brain.

Primary pulmonary myxoid sarcoma in the interlobar fissure of the left lung lobe: a case report.

BACKGROUND: Primary pulmonary myxoid sarcoma (PPMS) is a rare, low-grade malignant tumor, constituting approximately 0.2% of all lung tumors. Despite its rarity, PPMS possesses distinctive histological features and molecular alterations, notably the presence of EWSR1-CREB1 gene fusion. However, its precise tissue origin remains elusive, posing challenges in clinical diagnosis. CASE DEMONSTRATION: A 20-year-old male patient underwent a routine physical examination 6 months prior, revealing a pulmonary mass. Following surgical excision, microscopic evaluation unveiled predominantly short spindle-shaped tumor cells organized in a fascicular, beam-like, or reticular pattern. The stromal matrix exhibited abundant mucin, accompanied by lymphocytic and plasma cell infiltration, with Russell bodies evident in focal areas. Immunophenotypic profiling revealed positive expression of vimentin and epithelial membrane antigen in tumor cells, whereas smooth muscle actin and S-100, among others, were negative. Ki-67 proliferation index was approximately 5%. Subsequent second-generation sequencing identified the characteristic EWSR1-CREB1 gene fusion. The definitive pathological diagnosis established PPMS. The patient underwent no adjuvant chemotherapy or radiotherapy and remained recurrence-free during a 30-month follow-up period. CONCLUSIONS: We report a rare case of PPMS located within the left lung lobe interlobar fissure, featuring Russell body formation within the tumor stroma, a novel finding in PPMS. Furthermore, the histomorphological characteristics of this case highlight the diagnostic challenge it poses, as it may mimic inflammatory myofibroblastic tumor, extraskeletal myxoid chondrosarcoma, or hemangiopericytoma-like fibrous histiocytoma. Therefore, accurate diagnosis necessitates an integrated approach involving morphological, immunohistochemical, and molecular analyses.

Synovial myxosarcoma in the scapulohumeral joint of a dog: a case report.

A 12-year-old, 3 kg spayed female mixed-breed dog was evaluated to assess a 1-year history of intermittent right forelimb lameness that did not have adequate response to nonsteroidal anti-inflammatory drugs. The radiographic study performed under sedation showed multifocal radiolucent areas affecting both the right humerus and scapula with focal soft tissue swelling; a CT scan confirmed the existence of an aggressive and invasive soft tissue mass affecting the scapulohumeral joint. Fine needle aspiration results suggested a low-grade synovial sarcoma and therefore a scapulectomy was performed. The biopsy showed spindle to stellated cells immersed in a basophilic and mucinous (myxoid) matrix with mild to moderate anisocytosis, moderate anisokaryosis, some binucleated cells and sporadic multinucleated cells. These findings are consistent with low-grade synovial myxosarcoma, a not well described synovial neoplasm that can mimic other commonly seen joint tumors or even septic arthritis on radiographs. The purpose of this case report is to describe the first reported synovial myxosarcoma affecting the scapulohumeral joint of a small dog.

Bilateral testicular myxosarcoma in a cryptorchid dog.

Myxosarcoma is a rare malignant mesenchymal neoplasm of soft tissues originating from fibroblasts. This report describes a case of bilateral myxosarcoma in a three-year-old cryptorchid dog. The animal was referred to the veterinary clinic because of the absence of testicles in the scrotum. Ultrasonography revealed two masses in the abdominal cavity with testicular echotexture. Exploratory laparotomy revealed the presence of cryptorchid testicles, and orchiectomy was recommended to treat the animal. Testicles were gray and reddish in color and enlarged with firm consistency. For histopathological analysis, testis fragments were fixed in 10% formalin and stained with hematoxylin and eosin and Alcian blue. Immunohistochemistry was performed using the following primary antibodies:1A4, HHF35, desmin, glial fibrillary acidic protein, CD31, S-100, vimentin, and Ki-67. Histopathological evaluation revealed the proliferation of fusiform and round cells associated with extensive areas of myxoid matrix. Neoplasms featured multinucleated giant cells, pleomorphism, karyomegaly, nuclear hyperchromasia, anisokaryosis, mitoses, and necrosis, with coarse chromatin and prominent nucleoli. Immunohistochemical analysis of vimentin- and the Alcian blue-positive cells confirmed the diagnosis of myxosarcoma. A high mitotic count and Ki-67 proliferative index suggests this myxosarcoma had a high degree of malignancy. To the best of our knowledge, this is the first case report of bilateral testicular myxosarcoma in a cryptorchid animal.

Metastatic cutaneous myxosarcoma in an adult horse.

A 25-year-old mixed-breed equine with separate nodular cutaneous lesions in the right thoracic limb (RTL) and right ventral abdominal region was admitted to a Veterinary Hospital in Belo Horizonte, Minas Gerais. Fine-needle aspiration cytology was performed on the RTL lesion and superficial cervical lymph node, and the results were suggestive of a malignant neoplasm known as myxosarcoma. Due to the unfavorable prognosis, the animal was euthanized. Based on the macroscopic and microscopic findings, the diagnosis of metastatic cutaneous myxosarcoma was confirmed. Although rare, this tumor should be considered as a differential diagnosis for cutaneous neoplasms in this species.

[Myxosarcoma in the cervical region in a teddy bear hamster (Mesocricetus auratus)]. / Myxosarkom in der Halsregion eines Teddy-Hamsters (Mesocricetus auratus).

This case report describes a rare case of a myxosarcoma in a 1-year-old teddy bear hamster presenting with a mass in the cervical region. The fine-needle aspiration cytology revealed high numbers of pleomorphic spindle-shaped cells found in a viscous mucinous background. The presumptive cytological diagnosis was malignant spindle cell neoplasia based on marked criteria of malignancy of the mesenchymal cell population. The abundant matrix in the background was suggestive of a myxosarcoma. The hamster died during surgery and a necropsy was performed. Histopathology was in complete agreement with the cytological report. Immunohistochemistry revealed the tumour to be vimentin positive with alcian-blue positive matrix and confirmed the presumptive diagnosis of a myxosarcoma. This case shows that fine-needle aspiration cytology can be utilized as a minimally invasive diagnostic tool in small mammals to classify mass lesions. However, so far little is known about the biological behaviour of myxosarcoma in the hamster as case descriptions are rare.

A cardiac malignant primary tumor: Left atrium myxosarcoma-A case report.

Myxosarcoma only accounts for a very small proportion of primary malignant tumors of the heart. The disease has no specificity in clinical manifestations or features on medical images. In this case study, we report about a middle-aged female patient afflicted with cardiac myxosarcoma. The initial transthoracic echocardiography of the patient revealed a cardiac myxoma. However, the postoperative histopathology confirmed the presence of a malignant cardiac myxosarcoma. Post-surgery follow-up imaging examinations revealed local recurrence in the left atrium as well as soft-tissue and bone metastases. The recurrent tumor and metastases were subsequently treated with chemotherapy and radiotherapy. However, the tumor did not respond to treatment and the disease progressed.

Acute Presentation of a High-Grade Myxofibrosarcoma Originating in the Thoracic Wall: A Case Report.

We report the first case of a patient with myxofibrosarcoma (MFS) who presented acutely with a rib fracture and developed a rapidly expanding loculated hemothorax after chest trauma. The patient was taken to the operating room for evacuation of hemothorax, and samples and biopsy specimens were taken for cytologic and pathologic examination. Final report with immunohistochemical staining showed a high-grade MFS. After the procedure, there was clinical and radiological improvement, and the patient was followed up as an outpatient. Myxofibrosarcoma is a very rare and aggressive connective tissue neoplasm with variable presentations. Surgical resection is the preferred treatment. Prompt diagnosis and adequate management of these tumors are important to reduce their high local recurrence and distant metastasis rates. Therefore, it is important to be aware of its common and uncommon presentations.

T-regulatory cells predict clinical outcome in soft tissue sarcoma patients: a clinico-pathological study.

BACKGROUND: Soft tissue sarcomas (STS) are generally considered non-immunogenic, although specific subtypes respond to immunotherapy. Antitumour response within the tumour microenvironment relies on a balance between inhibitory and activating signals for tumour-infiltrating lymphocytes (TILs). This study analysed TILs and immune checkpoint molecules in STS, and assessed their prognostic impact regarding local recurrence (LR), distant metastasis (DM), and overall survival (OS). METHODS: One-hundred and ninety-two surgically treated STS patients (median age: 63.5 years; 103 males [53.6%]) were retrospectively included. Tissue microarrays were constructed, immunohistochemistry for PD-1, PD-L1, FOXP3, CD3, CD4, and CD8 performed, and staining assessed with multispectral imaging. TIL phenotype abundance and immune checkpoint markers were correlated with clinical and outcome parameters (LR, DM, and OS). RESULTS: Significant differences between histology and all immune checkpoint markers except for FOXP3+ and CD3-PD-L1+ cell subpopulations were found. Higher levels of PD-L1, PD-1, and any TIL phenotype were found in myxofibrosarcoma as compared to leiomyosarcoma (all p < 0.05). The presence of regulatory T cells (Tregs) was associated with increased LR risk (p = 0.006), irrespective of margins. Other TILs or immune checkpoint markers had no significant impact on outcome parameters. CONCLUSIONS: TIL and immune checkpoint marker levels are most abundant in myxofibrosarcoma. High Treg levels are independently associated with increased LR risk, irrespective of margins.

Surgery Treatment Improved the Overall Survival Rate in Locoregional Myxoid Leiomyosarcoma than Other Myxosarcomas in the United States.

Myxosarcomas are rare malignant tumors of soft connective tissues, classified into various subtypes, including myxoid liposarcoma, myxoid chondrosarcoma, and myxoid leiomyosarcoma. In this study, we proposed to study the demographic, tumor characteristics, and overall survival rate and compared the treatment modalities between these cancers. Patient data collected based on locoregional metastasis presentation of the abovementioned tumors with a cutoff study of survival duration up to 10 years were obtained from the SEER database during 1975-2016. Our results indicated that elderly patients and females were more in locoregional myxoid leiomyosarcoma than myxoid liposarcoma and myxoid chondrosarcoma with locoregional metastasis. The white race represented the most patients who suffered from these cancers than other races. The heart is the primary site for the abovementioned cancers, in addition to the female genitals to the myxoid leiomyosarcoma. Myxoid liposarcoma and myxoid chondrosarcoma patients with locoregional metastasis were suffering from grade II, while locoregional myxoid leiomyosarcoma patients with blank grading were due to missed data. Surgery was the most common treatment modality in this study compared with radiotherapy and chemotherapy. Kaplan-Meier analysis showed a significant difference in survival time between the three subtypes by using histology, and myxoid leiomyosarcoma showed prolonged survival than others. Elderly, female, white, unknown grade, surgery, no radiation, and no chemotherapy variables were independent factors associated with overall survival among these cancers. Multivariate analysis also showed significant differences in overall survival between the three tumors by histology, and myxoid leiomyosarcoma was with a better prognosis than others. Multivariate analysis of locoregional myxoid leiomyosarcoma showed the statistical significance of black race, grade, and radiotherapy, indicating them as independent prognostic factors of locoregional myxoid leiomyosarcoma. We conclude that surgery was the primary treatment modality against these cancers than radiotherapy and chemotherapy. And the locoregional myxoid leiomyosarcomas showed a better prognosis and higher survival rate than locoregional myxoid liposarcoma and locoregional myxoid chondrosarcoma.

Remarkable response to anti-PD1 immunotherapy in refractory metastatic high-grade myxofibrosarcoma patient: A case report.

INTRODUCTION: Myxofibrosarcoma (MFS) is a locally aggressive tumor and has the potential to be fatal because of distant metastasis. Immunotherapy targeting either programmed cell death protein 1 (PD-1) or programmed death ligand 1 (PD-L1) has recently shown a curative effect on multiple cancers including melanoma, non-small cell lung cancer, and renal cell carcinoma. Although the immunotherapy has been applied in sarcoma, there is little information about the efficiency to treat metastatic MFS. PATIENT CONCERNS: A 42-year-old male presented to the clinic with a mass in the left thigh. Mass resection and ligament replacement surgery were performed. DIAGNOSES: The patient was diagnosed as high-grade MFS (federation nationale des centres de lutte contre le cancer, Grade 3) with pulmonary metastasis. INTERVENTIONS: In the past few years, he was treated with surgery, chemoradiotherapy, and Anlotinib (an angiogenesis inhibitor), but the metastatic lesion continued to progress. About 40% to 50% of tumor cells in his pulmonary tissues were showed positive PD-L1 expression and his tumor mutational burden was 215Muts. Thus, he received Camrelizumab (PD-1 inhibitor). OUTCOMES: Six months after the initiating immunotherapy of Camrelizumab, the size of pulmonary lesions showed marked shrinkage, indicating a partial response. After a follow-up of 18 months, the patient remained in good condition without progressive disease. CONCLUSION: This case described here demonstrated that immunotherapy of PD-1 inhibitor is a promising treatment option for refractory MFS with PD-L1 positive or tumor mutational burden -high, which could contribute to effective tumor response.

A clinicopathologic examination of myxofibrosarcoma. Do surgical margins significantly affect local recurrence rates in this infiltrative sarcoma subtype?

BACKGROUND AND OBJECTIVES: Myxofibrosarcoma (MFS) is an aggressive soft tissue tumor with an unpredictable recurrence pattern. We sought to (a) determine whether margin status in MFS is correlated to rates of local recurrence (LR) and (b) identify demographic and treatment variables associated with disease-related outcomes in this population. METHODS: This retrospective study identified 42 surgically treated patients with MFS over 10 years at a single institution. Patient demographics, tumor characteristics, intraoperative variables, and disease-related outcomes were recorded. RESULTS: Thirty-three (83%) patients had negative surgical margins and seven (18%) had positive margins. Four of 32 patients (13%) with negative margins developed subsequent LR compared to six of seven (86%) patients with positive margins (p < .001). Three patients (75%) with metastatic disease were deceased at the end of the study, while five (15%) without metastasis were deceased (p = .024). CONCLUSIONS: Positive margin procedures for MFS were associated with LR. However, negative surgical margins demonstrated a relatively high rate of LR compared to other soft tissue sarcoma subtypes. Furthermore, though MFS tends to locally recur and have a propensity for distant metastasis, patients are observed to have a higher probability of death from other causes.

Systemic Inflammation Is Associated with Oncological Outcome in Patients with High-Grade Myxofibrosarcoma of the Extremities: A Retrospective Analysis.

BACKGROUND: The aim of this retrospective study is to verify whether preoperative systemic inflammatory markers (serum C-reactive protein [CRP] and neutrophil-lymphocyte ratio [NLR]) can help in predicting the disease-specific survival (DSS) and local recurrence (LR) rate in adult patients affected by localized myxofibrosarcoma (MFS) of the extremities. METHODS: We reviewed 126 adult patients with primary, localized MFS of the limbs. We analyzed DSS and LR. RESULTS: Median age at the time of surgery was 68 years (range 19-92). Median CRP was 0.4 mg/dL and median NLR was 2.8. A worse DSS was found in patients who had preoperative CRP >0.5 mg/dL (p = 0.002) and in those with NLR >3.5 (p < 0.001). In multivariate analysis, tumor size and grade as well as preoperative CRP values and NLR were confirmed to be prognostic factors in terms of DSS. An increased risk of LR was found in multivariate analysis in patients with a tail sign and with high gadolinium enhancement at preoperative MRI. CONCLUSIONS: Patients with high preoperative CRP and NLR levels, as well as large and high-grade tumors, might be considered as candidates for additional, more aggressive treatment approaches or more stringent follow-up schedules.

Primary Pulmonary Myxoid Sarcoma and Myxoid Angiomatoid Fibrous Histiocytoma: A Unifying Continuum With Shared and Distinct Features.

Primary pulmonary myxoid sarcoma (PPMS) is a recently reported, exceedingly rare low-grade lung neoplasm characterized by reticular/lace-like growth of spindle to epithelioid cells embedded in an abundant myxoid matrix. Morphologically, it overlaps with a myxoid variant of angiomatoid fibrous histiocytoma (AFH) of the soft tissue. Genetically, they were both reported to harbor EWSR1-CREB1 fusion, while EWSR1-ATF1 has only been reported in AFH thus far. We report a case of primary pulmonary low-grade myxoid spindle cell tumor with morphologic and immunohistochemical features of PPMS but with an EWSR1-ATF1 fusion gene. In addition, we also encountered a case of endobronchial AFH with EWSR1-CREB1 translocation but also focal morphologic features of PPMS. These findings provide new evidence supporting the concept that PPMS and a myxoid variant of AFH represent a continuum with overlapping histologic, immunohistochemical, and genetic features.

Obstructive right ventricular outflow tract myxosarcoma in an adult dog.

An 8-year-old female spayed German Shepherd cross was presented for acute onset of respiratory distress. Four days before presentation, the owner noticed a reduced appetite and reluctance to move. Clinical examination identified muffled lung sounds and a left base, diamond-shaped systolic murmur graded 4/6. Echocardiography identified pleural and pericardial effusion, ascites and a myxoid mass (39 mm/18.9 mm) obstructing the right ventricular outflow tract and interfering with the pulmonary valve function. Given the poor prognosis, the dog was euthanatised, and a postmortem examination was performed. Grossly, a mass with a heterogeneous appearance was identified below the pulmonary valve leaflets. Based on histopathological and immunohistochemical findings, a diagnosis of intracardiac myxosarcoma affecting the subvalvular region of the pulmonary artery was made. To the author's knowledge, this is the first report of right ventricle out flow tract myxosarcoma in the canine species.

Grading in Myxofibrosarcoma of the Extremities Can Predict Survival and Local Control.

BACKGROUND: The aim of this retrospective analysis is to understand the natural history of myxofibrosarcoma (MFS), in particular whether the prognosis can be influenced by histologic grade. METHODS: We reviewed 229 adult patients with primary MFS of the limbs. We analyzed disease-specific survival (overall survival [OS]) and local recurrence (LR). RESULTS: Median age was 70 years (range, 19-92). Sixteen (7.0%) were grade 1, 38 (16.6%) grade 2, and 175 (76.4%) grade 3. A worse OS was found in grade 3 MFS (73.1%) than in grade 2 and 1 MFS (91.9 and 100%, respectively) at 5 years (p = 0.031). Locally recurred MFS had a worse OS (p = 0.018). A better LR-free rate (100% at 5 years) was observed in grade 1 MFS; however, a similar rate was observed between grade 2 and 3 tumors (77.1 and 80.0% at 5 years, respectively, p = 0.412). CONCLUSIONS: Grade 3 MFS has the worst prognosis. Grade 1 MFS have the lowest risk of LR. These data could help identify a high-risk patient group, thus selecting a more careful follow-up for higher-risk patients. Since MFS mostly affects the elderly population, it might be useful to reserve adjuvant treatments (radiotherapy and chemotherapy) to higher-risk patients.

Cytomorphologic findings of low-grade fibromyxoid sarcoma.

INTRODUCTION: Low-grade fibromyxoid sarcoma (LGFMS) is a rare fibroblastic tumor characterized by a prolonged clinical course and malignant biological behavior. Given its deceptively bland cytomorphology, a diagnosis can be quite challenging notably on fine-needle aspiration (FNA). In an attempt to shed light on some of the distinctive cytomorphologic characteristics, this study was conducted to review all cases of LGFMS in our database, correlating available clinical data, immunohistochemical findings, and molecular analysis. MATERIALS AND METHODS: This series included 20 FNAs from 18 patients with a histologically confirmed LGFMS diagnosis from 3 large academic institutions. Detailed cytomorphologic analysis for each case was documented in conjunction with corresponding clinical characteristics and provided ancillary testing. RESULTS: Out of 14 adequate FNA samples, 9 (64.2%) demonstrated a mixture of fibrous and myxoid pattern; the majority of cases were composed of deceptively bland tumor cells with rare nuclear pleomorphism and nuclear membrane irregularities. A MUC4 immunostain was performed on 5 specimens; all tested positive (100%). FUS rearrangement was detected in 4 out of 5 cases (80%). Follow-up information revealed 5-year recurrence in 1 case and metastatic disease in 2 cases, to the lung/pleura (8 years) and fourth rib (1 year), respectively. CONCLUSIONS: The presence of bland spindle cells and associated with myxoid matrix material, in the appropriate clinical setting, can suggest LGFMS and direct additional confirmatory testing. A definitive diagnosis of LGFMS on FNA requires adequate sampling, familiarity with key cytomorphologic features, acquisition of diagnostic material for a cell block preparation and ancillary testing, and clinicoradiologic correlation.