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.

Myxofibrosarcoma - Case report.

Myxofibrosarcoma is recognized as a malignant neoplasm of fibroblastic origin with increased prevalence in the elderly, presenting as nodules or tumors that may extend to the dermis and skeletal muscle, preferably in the lower limbs. Histologically it is characterized by a proliferation of spindle cells in a myxoid stroma. Myxofibrosarcoma has a high potential for local recurrence and metastasis, mainly when it presents a high or intermediate histological grade. We report the case of an eighty-four year old patient with a difficult diagnosis of a highly aggressive tumor.

Myxofibrosarcoma - Case report

Abstract Myxofibrosarcoma is recognized as a malignant neoplasm of fibroblastic origin with increased prevalence in the elderly, presenting as nodules or tumors that may extend to the dermis and skeletal muscle, preferably in the lower limbs. Histologically it is characterized by a proliferation of spindle cells in a myxoid stroma. Myxofibrosarcoma has a high potential for local recurrence and metastasis, mainly when it presents a high or intermediate histological grade. We report the case of an eighty-four year old patient with a difficult diagnosis of a highly aggressive tumor.

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.

Canine low-grade intra-orbital myxosarcoma: case report.

OBJECTIVE: The aim of this study was to evaluate important clinical, morphological, histopathological, histochemical, and immunohistochemical characteristics in order to establish the diagnosis and prognosis of a low-grade intra-orbital myxosarcoma. ANIMAL STUDIED: A mongrel dog presented a 2-year history of a neoplastic mass behind the right eye. RESULTS: The neoplasm presented a mesenchymal spindle and stellate cell proliferation with an abundant myxoid matrix, moderate anisocariosis, and a low mitotic index. It stained positive for vimentin, moderately positive for periodic acid-Schiff, and negative for Gomori trichrome stain and α-smooth muscle actin. CONCLUSIONS: One year following surgical excision, the patient remains disease free. The histological findings established a diagnosis of a rare canine intra-orbital low-grade myxosarcoma.

Mixofibrossarcoma--case report.

Myxofibrosarcoma, previously known as malignant fibrous histiocytoma, myxoid variant, is a rare tumor of mesenchymal origin, composed of spindle cells and myxoid stroma. It mainly affects elderly people, involving the lower extremities and frequently extending to the dermis and subcutaneous tissue. The tumor presents high rates of recurrence, and a deep biopsy is required to obtain the correct diagnosis. We report a case of high-grade mixofibrossarcoma characterized by a rapidly growing tumor and the presence of marked cellular pleomorphism and an abundant myxoid matrix.

Mixofibrossarcoma: relato de caso / Mixofibrossarcoma: case report

O mixofibrossarcoma, previamente conhecido como histiocitoma fibroso maligno, variante mixoide, é um tumor raro, de origem mesenquimal, composto por células fusiformes e estroma mixoide. Acomete mais idosos, envolvendo extremidades inferiores e estendendo-se, em sua maior parte, até a derme e o subcutâneo. Apresenta altas taxas de recorrência e para seu diagnóstico é fundamental a realização de uma biópsia profunda. Relataremos o caso de um mixofibrossarcoma de alto grau, caracterizado por lesão tumoral de crescimento rápido e pela presença de marcado pleomorfismo celular e componente mixoide em abundância.

Myxofibrosarcoma, previously known as malignant fibrous histiocytoma, myxoid variant, is a rare tumor of mesenchymal origin, composed of spindle cells and myxoid stroma. It mainly affects elderly people, involving the lower extremities and frequently extending to the dermis and subcutaneous tissue. The tumor presents high rates of recurrence, and a deep biopsy is required to obtain the correct diagnosis. We report a case of high-grade mixofibrossarcoma characterized by a rapidly growing tumor and the presence of marked cellular pleomorphism and an abundant myxoid matrix.

Myxoinflammatory fibroblastic sarcoma showing t(2;6)(q31;p21.3) as a sole cytogenetic abnormality.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade sarcoma characterized by distinctive, large, and bizarre Reed--Sternberg--like cells associated with an intense inflammatory infiltrate. The biology of MIFS is still poorly understood, and only two previous cases had been studied cytogenetically. In the present case, analysis of MIFS in the foot of a 53-year-old man revealed the chromosome translocation t(2;6)(q31;p21.3) as the only cytogenetic abnormality. This finding is distinct from the two cases previously reported. Additional studies are needed to verify whether any of these chromosome rearrangements are involved recurrently in MIFS.

Mixossarcoma atrial esquerdo: relato de caso / Left atrial myxosarcoma: case report

O mixossarcoma é uma forma rara de neoplasia cardíaca primária de difícil diferenciação clínica e patológica com o mixoma. Até onde os autores têm conhecimento, este é o primeiro relato de caso na literatura nacional indexada com o tratamento cirúrgico do mixossarcoma atrial esquerdo, em paciente do sexo feminino, de 36 anos de idade, cuja evolução pós-operatória tem sido satisfatória, encontrando-se em classe funcional I (NYHA) e em remissão do processo tumoral há mais de 180 dias.