Obstructive cardiac myxosarcoma of the right ventricular outflow tract with pulmonary embolism and concurrent right atrial hemangiosarcoma in a dog.

A 13-year-old spayed female rottweiler crossbreed dog was presented with an 8-day history of abnormal gait and collapse associated with excitement or physical activity. A cardiac gallop was noticed on thoracic auscultation, and a 1st-degree atrioventricular block and sinus tachycardia were noted on an electrocardiogram. Echocardiography identified a hypoechoic, irregularly marginated luminal mass in the right ventricle at the level of the pulmonic valves. Postmortem gross examination confirmed the presence of a soft, polypoid, and botryoid mass (9 × 3 × 3 cm) with a smooth and glistening surface attached to the endocardium of the right ventricular outflow tract and extending to the pulmonary artery. The histological findings were consistent with the diagnosis of myxosarcoma with pulmonary embolism. In addition, the dog in this report had a right atrial hemangiosarcoma and a cutaneous hemangioma unrelated to her clinical findings. Key clinical message: Cardiac myxosarcomas are very rare neoplasms in dogs and concomitant primary heart tumors of different histogenesis are even rarer in dogs. To the authors' knowledge, this is the first report of coexistent myxosarcoma and hemangiosarcoma in the heart of a dog. Cardiac myxosarcomas should be considered in the differential diagnosis of intracavitary heart masses associated with signs of cardiac obstruction and failure.

Myxosarcome cardiaque obstructif de la voie d'éjection du ventricule droit avec embolie pulmonaire et hémangiosarcome auriculaire droit concomitant chez un chien. Une chienne croisée rottweiler stérilisée âgée de 13 ans a été présentée avec une histoire de démarche anormale et d'effondrement associés à l'excitation ou à l'activité physique depuis 8 jours. Un galop cardiaque a été noté à l'auscultation thoracique, un bloc auriculo-ventriculaire du 1er degré et une tachycardie sinusale ont été notés à l'électrocardiogramme. L'échocardiographie a permis d'identifier une masse luminale hypoéchogène et irrégulièrement marginalisée dans le ventricule droit au niveau des valvules pulmonaires. L'examen macroscopique post-mortem a confirmé la présence d'une masse molle, polypoïde et botryoïde (9 × 3 × 3 cm) avec une surface lisse et brillante attachée à l'endocarde de la voie d'éjection du ventricule droit et s'étendant jusqu'à l'artère pulmonaire. Les résultats histologiques concordaient avec le diagnostic de myxosarcome avec embolie pulmonaire. De plus, la chienne dans ce rapport présentait un hémangiosarcome auriculaire droit et un hémangiome cutané sans rapport avec ses résultats cliniques.Message clinique clé :Les myxosarcomes cardiaques sont des néoplasmes très rares chez le chien et les tumeurs cardiaques primaires concomitantes d'histogenèse différente sont encore plus rares chez le chien. À la connaissance des auteurs, il s'agit du premier rapport de myxosarcome et d'hémangiosarcome coexistant dans le cœur d'un chien. Les myxosarcomes cardiaques doivent être pris en compte dans le diagnostic différentiel des masses cardiaques intracavitaires associées à des signes d'obstruction et d'insuffisance cardiaque.(Traduit par Dr Serge Messier).

[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.

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.

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.

Comparison of the diagnostic performances of core needle biopsy in myxoid versus non-myxoid tumors.

BACKGROUND: Despite the overall diagnostic utility of core needle biopsy (CNB) comparable to incisional biopsy, increased diagnostic errors have been suggested of CNB for myxoid soft tissue tumors. This study compared the diagnostic performance of CNB between myxoid and non-myxoid soft tissue tumors. METHODS: 369 patients who underwent ultrasound-guided CNB prior to resection for soft tissue tumors were classified into two groups according to resection pathology; myxoid group (n = 75) and non-myxoid group (n = 294). One-hundred and ninety-three patients were male and the median age of the patients was 40 years. Two-hundred and sixty-three tumors were malignant. RESULTS: CNB correctly diagnosed malignancy in 84% (58 of 69) for the myxoid group and 95% (184 of 194) for the non-myxoid group. For diagnosing histologic grade of soft tissue sarcoma, CNB correctly identified high grade in 78% (18 of 23) for the myxoid group and 74% (94 of 128) for the non-myxoid group. Correct diagnosis rate of histological type was significantly lower in the myxoid group (63% [47 of 75] in the myxoid group and 83% [242 of 294] in the non-myxoid group, p = 0.013). CONCLUSION: Our study suggests that CNB is useful for myxoid soft tissue tumors of the extremity, with regard to diagnosing malignancy and histologic grade. However, CNB was less useful for identifying histologic subtype in myxoid tumors than in non-myxoid tumors.

Aggressive myxoinflammatory fibroblastic sarcoma with multiple site metastases.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare soft tissue sarcoma which was initially observed in acral sites and characterised by spindle cells, pleomorphic bizarre cells and distinctive large Reed-Sternberg-like cells admixed with an intense inflammatory cell infiltrates. MIFS manifests as a slow growing often superficial lesion which can be mistaken as infectious or chronic inflammatory process or benign tumours such as nodular fasciitis, giant cell tumour of tendon sheath or synovial pseudocyst. We report a rare presentation of a MIFS in a 38-year-old man with extensive local spread from subcutaneous tissue to the ankle joint and bones as well as multiple synchronous metastases to lung, sixth rib and vertebra. Our case is peculiar for its aggressive clinical behaviour with short duration, fast growth and extensive metastases, a feature infrequent in MIFS.

Myxoinflammatory Fibroblastic Sarcoma: Review and Update.

Myxoinflammatory fibroblastic sarcoma is a rare soft tissue tumor with most occurring in the distal extremities of adult patients. It has a high rate of local recurrence and a low rate of metastasis. Because it may appear benign on clinical examination, and because the microscopic features are generally underrecognized, it is often inadequately treated and misdiagnosed. In this review, based upon experience and that of the literature, the intent is to highlight salient clinicopathologic features, detail the broad microscopic spectrum including high-grade aggressive variants, review the molecular features, and discuss its relation to hemosiderotic fibrolipomatous tumor.

A rare presentation of myxofibrosarcoma as a Pancoast tumor: a case report.

BACKGROUND: Myxofibrosarcoma is an aggressive soft tissue neoplasm, classified as a variant of malignant fibrous histiocytoma. Most often, it occurs in middle to late adult life peaking in the seventh decade and involving the lower extremities (77%), trunk (12%), and retroperitoneum or mediastinum (8%). We report the first case of thoracic myxofibrosarcoma presenting as a Pancoast tumor. CASE PRESENTATION: A 48-year-old non-tobacco smoking African-American man presented with a slow-growing mass in his neck along with 11 kg weight loss over 9 months. A review of his systems was positive for hoarseness and lowgrade intermittent fever without any shortness of breath or cough. A physical examination revealed a mass on the left side of his neck superior to his sternoclavicular joint measuring 3 × 3 × 1 cm. He had ptosis and miosis of his left eye. His breath sounds were decreased and coarse at the left apex. A neurological examination revealed 3/5 strength in his left upper arm. The remainder of the physical examination was unremarkable. Ultrasound of his neck showed an ill-defined heterogeneous mass lateral to his left thyroid lobe. A computed tomography scan of his chest showed a large multiloculated pleural-based mass in his left lung surrounding the adjacent neurovascular structures. A percutaneous biopsy was non-diagnostic. Subsequently, he underwent a left thoracotomy with biopsy. The mass extended from his anterior mediastinum medially at the level of the pulmonary trunk, superiorly into the superior sulcus and posteriorly into his chest wall. Surgical pathology confirmed the diagnosis of myxofibrosarcoma. CONCLUSIONS: Here we present a case of Pancoast tumor with myxofibrosarcoma as the underlying etiology. Pancoast syndrome generally entails an infiltrating lesion in the superior sulcus presenting with upper extremity pain, atrophy of the hand muscles, and Horner's syndrome. The differential diagnosis of Pancoast syndrome includes inflammatory and infectious etiologies, as well as neoplasms of benign and malignant nature. Of the neoplasms implicated, the most common are non-small cell lung carcinomas; myxofibrosarcoma presenting as a Pancoast tumor has not been reported in the literature.

Mixofibrosarcoma de bajo grado: reporte de caso / Low grade mixofibrosarcoma: case report

El mixofibrosarcoma es un subtipo de sarcoma que comúnmente se presenta en las extremidades de personas ancianas. La presentación clínica no es característica y el aspecto histológico es altamente heterogéneo, lo que frecuentemente retrasa el diagnóstico o conduce a uno equivocado. Técnicas de histoquímica e inmunohistoquímica son mandatorias para establecer el diagnóstico de MFS. Presentamos el caso de un hombre de 57 años para ilustrar lo poco sugerente de este diagnóstico dada la presentación clínica. El manejo de este tumor es con cirugía, eventualmente radioterapia y seguimiento estricto.

Myxofibrosarcoma is a subtype of sarcoma commonly found in the extremities of elderly people. The clinical presentation is not characteristic and the histological aspect is highly heterogeneous, which often delays the diagnosis or leads to the wrong one. Histochemistry and immunohistochemistry techniques are required to establish the diagnosis of SFM. We present the case of a 57-year-old man to illustrate the unimpressive nature of this diagnosis given the clinical presentation. The management of this tumor is with surgery, eventually radiotherapy and strict follow-up.

High-grade myxofibrosarcoma-presented as a large mass of right upper arm.

Myxofibrosarcoma is one of the rare soft tissue sarcomas. We present a case of a 65-year-old male having large soft tissue mass over right upper arm associated with surface ulceration. On histopathological study tumor was diagnosed as myxofibrosarcoma - high grade according to modified FNCLCC grading system. Like many other tumors of connective tissue, soft tissue sarcoma exhibits high recurrence. In our case, tumor showed features of high grade with local recurrence, large size; however, no evidence of metastasis was noted. For this unpredictable clinical behavior, we are presenting this case.

Axillary artery tumor embolism secondary to mitral valve myxosarcoma in a dog.

OBJECTIVE: To describe the clinical presentation, treatment, and outcome of a dog with an arterial tumor embolism. CASE SUMMARY: An 11-year-old, neutered male Irish Setter presented with acute right forelimb lameness. The dog was unable to bear weight on the right forelimb, which was cool to the touch with no palpable pulses. Diagnosis of thromboembolism was confirmed using angiography, revealing a lack of blood flow to the right axillary artery. Balloon angioplasty, thrombosuction, and infusion of the thromboembolism with tissue plasminogen activator were used to achieve increased, but not complete, blood flow through the vasculature. Echocardiogram revealed vegetative mitral valve lesions consistent with endocarditis, thrombus, neoplasia, or a combination thereof. At the time of discharge, there was improvement in the temperature and motor function of the proximal limb but no conscious proprioception or deep pain sensation in the distal limb. Histopathologic analysis of the sample retrieved with thrombosuction was consistent with a diagnosis of myxosarcoma. A series of 3 rechecks showed continued improvement in neuromuscular function. Treatment for suspected mitral valve myxosarcoma was declined. The patient was lost to follow up until being presented for necropsy 16 months later. Necropsy confirmed myxosarcoma of the mitral valve with tumor emboli to the coronary arteries, lungs, and the right axillary artery. UNIQUE INFORMATION PROVIDED: To the authors' knowledge, there is no report of myxosarcoma originating on the mitral valve in dogs, although it has been reported in the human literature. To the authors' knowledge, there are also no reports of tumor embolism of the axillary artery in a dog. This case demonstrates a unique presentation of a dog that had a myxosarcoma tumor embolism. It also describes the use of angiography for diagnosis and localization of the vascular obstruction and a variety of interventional techniques for the treatment of thromboembolism.

Myxoinflammatory fibroblastic sarcoma: morphologic and genetic updates.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a malignant mesenchymal neoplasm most frequently arising in the distal extremities of adults, which usually behaves in a low-grade manner but is capable of metastasizing to local and distant sites, rarely leading to death. It is a rare tumor whose unusual morphology can lead to erroneous histologic diagnosis, either as a nonneoplastic (infectious or inflammatory) process or as a variety of neoplastic diseases. While its exact origin is uncertain, ultrastructural studies have shown at least some of the constituent cells to be modified fibroblasts. Distinct and reproducible genetic abnormalities identified in MIFS are translocation t(1;10)(p22:q24), with rearrangements of the TGFBR3 and MGEA5 genes associated with increased levels of FGF8, and formation of marker/ring chromosome 3, with amplification of the VGLL3 locus. Because these genetic abnormalities are shared by both MIFS and hemosiderotic fibrohistiocytic lipomatous tumor, it is thought that these 2 morphologically distinct neoplasms may comprise a spectrum of disease defined by these genetics. We review the literature on MIFS and discuss morphology (including that of MIFS/hemosiderotic fibrohistiocytic lipomatous tumor hybrid lesions), immunohistochemistry, the differential diagnosis, and recent molecular genetic developments.

Diagnosis and treatment of a periocular myxosarcoma in a bearded dragon (Pogona vitticeps).

A 5-year-old male Australian bearded dragon (Pogona vitticeps) was presented with a 2-month history of a periocular mass. The clinical evaluation included a physical examination, hematology, biochemistry, and radiographs. The mass was treated surgically and diagnosed as myxosarcoma. Strontium-90 plesiotherapy was attempted, but the mass recurred 5 mo later.

Diagnostic et traitement d'un myosarcome périoculaire chez un dragon barbu(Pogona vitticeps) . Un dragon barbu mâle âgé de 5 ans (Pogona vitticeps) a été présenté avec une anamnèse de masse périoculaire apparue depuis 2 mois. L'évaluation clinique a inclus un examen physique, une hématologie, une biochimie et des radiographies. La masse a été traitée par chirurgie et diagnostiquée comme un myosarcome. Une plésiothérapie au strontium-90 a été tentée, mais la masse est revenue 5 mois plus tard.(Traduit par Isabelle Vallières).

Cardiac myxosarcoma with thoracic spinal metastasis.

Echocardiography revealed a left atrial tumor in a 59-year-old man with back pain that concurrently worsened with left foot drop and loss of the left ankle reflex soon after admission to our hospital. Magnetic resonance imaging of the spine revealed an epidural tumor extending from Th5 with spinal cord compression. The patient was immediately treated by emergency Th4-5 laminectomy and epidural decompression. One month later, a cardiac tumor excised via the left atrial approach was histopathologically diagnosed as myxosarcoma, and the Th5 tumor was consistent with this finding. This is the first report to describe spinal metastasis of cardiac myxosarcoma.