Ultrasound and MRI features of malignant fibrous histiocytoma of soft tissue / 中国骨伤

OBJECTIVE@#To investigate ultrasound and MRI features of malignant fibrous histiocytoma (MFH) of soft tissue.@*METHODS@#Ultrasound, MRI images and pathological data of 12 patients with malignant fibrous histiocytoma in soft tissue confirmed by operation and pathology were analyzed from January 2012 to August 2018, inlcuding 7 males and 5 females, aged from 36 to 69 years old with an average age of 53 years old; the courses of disease ranged from 4 to 49 months with an average of 28 months. Clinical manifestations were soft tissue masses and pain in the affected limbs. Ultrasound, MRI and contrast-enhanced examination were performed before operation. The lesions, morphology, echo/signal characteristics, color flow signals and enhancement features were observed and compared with pathology.@*RESULTS@#In 12 patients with MFH, 9 patients were primary lesions and 3 patients were recurrent lesions after operation. There were 7 cases of bilateral thighs, 2 cases of calves, 1 case of upper arm, 1 case of buttocks and 1 case of posterior peritoneum. The size ranged from 5.1 to 17.1 cm with an average of 8.7 cm. Ultrasound feature showed lobulated or agglomerate, and focused on low echo; 5 cases had capsule and with clear border; 7 cases were unclear boundary with surrounding tissues; and 6 cases with irregular echo-free. The blood flow signals were around the CDFI, and the internal blood flow signals were different. MRI feature showed lobulated, agglomerate or irregular shape, T1WI showed slightly lower signal or equal signal, T2WI showed high signal and DWI signal increased. Six patients manifested mixed signal inside, 7 patients manifested low signal separation inside, 5 patients with false envelope, and 9 patients manifested infiltration and growth with peripheral edema. T1WI showed uneven strengthening after enhancement. Immunohistochemical expression of Vim, CD68 were positive.@*CONCLUSIONS@#The age, location and imaging features of soft tissue MFH are characteristic. The diagnosis of MFH should be considered when irregular mass occurred in soft tissues of limbs at middle-aged and old people. Echo and signal are homogeneous or mixed. Separation, necrosis and cystic degeneration could be seen in the mass. When the blood flow signals are abundant and solid components are obviously enhanced, the diagnosis of MFH should be considered.

Undifferentiated pleomorphic sarcoma of the orbital region: a case report / Sarcoma pleomórfico indiferenciado da região orbitária: relato de caso

ABSTRACT Undifferentiated pleomorphic sarcoma (UPS) is an extremely rare tumor that occurs in the head and neck region. Here, we report a unique case of a primary undifferentiated pleomorphic sarcoma in the orbital region. A 35-year-old woman presented with a progressive proptosis and periocular edema for 1 year. She had no previous history of surgery, skin malignancy, or radiation. Imaging tests showed an extraconal mass, not involving the muscles. The tumor was surgically removed and adjuvant radiotherapy was required after histological examination, which showed an undifferentiated pleomorphic sarcoma of the orbit. There was no recurrence after 1 year of follow-up. Though rare, undifferentiated pleomorphic sarcoma should be included in the differential diagnoses of orbital tumors.

RESUMO O sarcoma pleomórfico indiferenciado (SPI) é um tumor extremamente raro na região da cabeça e pescoço. Relatamos um caso de um sarcoma pleomórfico indiferenciado primário na região orbital. Uma mulher de 35 anos apresentou proptose progressiva e edema periocular há um ano. Ela não tinha histórico prévio de cirurgia, malignidade da pele ou radiação. Exames de imagem mostraram uma massa extraconal, poupando os músculos. O tumor foi removido cirurgicamente e foi necessária radioterapia adjuvante após o resultado histopatológico. O exame histológico demonstrou um sarcoma pleomórfico indiferenciado da órbita. Não houve recidiva após 1 ano de seguimento. Apesar de raro, o sarcoma pleomórfico indiferenciado deve ser incluído no diagnostico diferencial de qualquer tumor originado na órbita.

Histiocitoma fibroso maligno pleomórfico estoriforme del brazo izquierdo / Malignant pleomorphic storiform fibrous histiocytoma of the left arm

Fundamento: el histiocitoma fibroso maligno es el sarcoma de partes blandas más frecuente en la adultez. Se encuentra en su mayoría en las extremidades en un 70-75 % y los miembros inferiores son los más afectados con el 60 %. Objetivo: presentar un caso de histiocitoma fibroso maligno pleomórfico estoriforme del brazo izquierdo que recibió tratamiento quirúrgico en el Hospital Universitario Manuel Ascunce Domenech de Camagüey en el 2016. Caso clínico: paciente masculino de 60 años, con aumento de volumen de la cara posterolateral proximal del brazo izquierdo, redondeado y acompañado de circulación colateral. Se palpó tumoración de 20 cm de diámetro, de superficie lisa, firme, fija a planos profundos y dolorosa a la palpación con auscultación negativa. La radiografía simple de húmero izquierdo informó una radiopacidad homogénea de las partes blandas circundantes del extremo proximal del húmero, sin reacción perióstica ni lesión ósea. La ecografía de partes blandas demostró imagen ecogénica de 200 x 170 mm, que se interponía entre los músculos deltoides y tríceps braquial, con seudocápsula bien definida y que respetaba el húmero. Se realizó biopsia por aspiración que informó una neoplasia maligna mesenquimátosa, posible histiocitoma maligno. Se decidió tratamiento quirúrgico consistente en excéresis del tumor con márgenes oncológicos. La biopsia definitiva luego de la inmunohistoquímica, informó un histiocitoma fibroso maligno pleomórfico estoriforme. Se remite para tratamiento oncológico con radioterapia, presentó una recidiva local por lo que se decidió amputación interescapulotorácica. Conclusiones: el histiocitoma fibroso maligno es el tumor maligno de partes blandas más frecuente del adulto. Presenta diferentes variantes histológicas por lo que la inmunohistoquímica es clave para el diagnóstico de certeza. La cirugía y la radioterapia son la mejor combinación terapéutica. La edad, la profundidad de la lesión, la variante histológica, la localización, la ausencia de metástasis y el tamaño son los factores pronósticos más importantes.

Background: malignant fibrous histiocytoma is the most frequent soft tissue sarcoma in adulthood. It is seen in extremities in about 70-75 % and lower limbs are the most affected ones with 60 %. Objective: to present a case of malignant storiform pleomorphic histiocitoma of the left arm who underwent surgical treatment at universitary hospital Manuel Ascunce Domenech of Camagüey in 2016. Clinical case: a 60 year old male patient with a round increasing volume in posterolateral proximal left arm with collateral circulation. It was palpated a 20 cm diameter smooth, firm, fix to deep planes and painful mass with negative auscultation. Simple left humerus radiography informed a homogeneous radiopacity in surrounding soft tissues, no periosteal reaction or bone damage. Ecography of soft tissues: hypoecoic image of 200 x 170 mm between triceps and deltoid muscles reaction, with well defined pseudocapsule and no bone affection. An aspiration biopsy was done which inform a malignant mesenchimal neoplasia as a possible malignant histiocytoma. Surgical treatment was carried out to remove the tumor with oncologic margins. Final biopsy after immunohystochemical staining revealed a malignant fibrous pleomorphic storiform histiocytoma. The patient was sent to oncologic treatment with radiotherapy and a local recurrence was diagnosed, that is why a four quarter amputation was achieved. Conclusions: malignant fibrous histiocytoma is the most frequent soft tissue sarcoma in adulthood. There are different histological varieties, that is why immunohystochemical staining is a key tool for accurate diagnosis. Surgery and radiotherapy are the best therapeutic combination. Age, tumor depth, histological variety, location, absence of metastasis and size are the most important prognosis factors.

Clinical application value of MRI on malignant fibrous histiocytoma in soft tissue / 中国骨伤

<p><b>OBJECTIVE</b>To investigate imaging manifestation and clinical application of MRI on malignant fibrous histiocytoma (MFH) in soft tissue.</p><p><b>METHODS</b>Imaging and pathological data of 16 patients with malignant fibrous histiocytoma (MFH) in soft tissue confirmed by surgery and pathology were retrospectively analyzed from January 2009 to August 2016. There were 9 males and 7 females, aged from 34 to 67 years old with an average of 52 years. The courses of disease ranged from 5 to 48 months with an average of 27 months.The main clinical manifestations were soft tissue mass and local pain. All patients were underwent plain and enhanced MRI before operation. Pathogenic sites, MRI manifestation and pathology results were observed after operation.</p><p><b>RESULTS</b>MRI in 16 cases of T1WI showde slightly lower signal or equal signals, of which 6 cases of tumor see mixed signal; in T2WI were high signal, of which 7 cases of internal tumor can be seen low signal separation, 5 cases of turor can be seen flase envelope, 11 cases of tumor with the surrounding boundaries unclear with edema. All lesions showed significantly uneven enhancement. Immunohistochemical examination showed that Vim, CD68 was positive.</p><p><b>CONCLUSIONS</b>Although MRI features of MFH has certain characteristics, the qualitative was more difficult, and ultimately need to determine the pathological and immunohistochemical. But MRI examination has obvious advantages in clarifying range of tumor, invading peripheral blood vessels and nerves, and has important clinical application value for clinical operation plan and postoperative tumor residual and recurrence, and provid reference for clinical curative effect.</p>

Histiocitoma fibroso maligno cerebral en paciente pediátrico: Presentación de un caso y revisión de la literatura / Malignant Fibrous Histiocytoma of the Brain in Pediatric Patient: A Case Report and Literature Review

Los tumores cerebrales son la segunda causa de neoplasias malignas en niños y los sarcomas primarios en el sistema nervioso central son extremadamente raros. Por esta razón, presentamos los resultados del estudio de un caso en una menor de edad y la revisión realizada sobre la fisiopatología, manifestaciones clínicas y hallazgos en las imágenes de resonancia magnética cerebral de esta patología. Se trata de una niña de 7 años de edad que ingresa al servicio de urgencias con cefalea, sintomatología sugerente de hipertensión endocraneana y disminución de la fuerza del hemicuerpo derecho, por lo que se le practica resonancia magnética cerebral (RM) con medio de contraste, con hallazgo de masa extraaxial temporoparietal izquierda, que desplaza la línea media. La paciente es valorada por neurocirugía y remitida a craneotomía frontoparietal izquierda, con resección completa del tumor. El informe de patología muestra sarcoma fusocelular de alto grado, compatible con histiocitoma fibroso maligno.

Brain tumours are the second cause of malignant neoplasms in children while primary sarcomas in the central nervous system (SNC), are extremely rare. For this reason, we present the results of the study of a case of a girl and revision on the pathophysiology, clinical manifestations, and findings on brain MRI of this pathology. We report the case of a sevenyear- old patient admitted to the emergency department with headache and symptoms suggestive of intracranial hypertension, and decreased strength of the right side of the body. In brain MRI, we found a left temporoparietal extra-axial mass, displacing the midline. The patient was examined by the neurosurgeon who performed a left frontoparietal craniotomy, with complete tumor resection. The pathology study showed high-grade spindle cell sarcoma, classified as malignant fibrous histiocytoma.

Clinical and pathological analysis of a case of metastatic myxoid melanoma with partial regression of the primary lesion / 中华皮肤科杂志

A 69-year-old male patient presented with a gradually enlarging mass in the left inner upper thigh for more than 2 months,and pigmented patches in the left medial leg for more than 20 years.Physical examination revealed a painless mass measuring 3 cm × 2 cm × 2 cm in size in the left inner upper thigh.Several pigmented patches were observed in the left medial leg,and the largest pigmented patch measured 2 cm× 2 cm in size with an irregular border and uneven pigmentation.The mass in the left inner upper thigh was resected and subjected to histopathological examination,which showed proliferative epithelioid neoplastic cells with mucous matrix,round and spindle cells of varying sizes separated by mucous matrix.The immunohistochemical study of tumor cells showed positive staining for vimentin,S100 and Melan-A,but negative staining for actin,desmin,CD56,epithelial membrane antigen,cytokeratin,leukocyte common antigen,CD99,chromogranin A and synaptophysin.Hematoxylin-eosin staining of pigmented patches on the left medial leg revealed squamous epithelium covering the surface of lesions with no superficial ulceration or atypia in epithelial cells,unevenly distributed melanophages,fibroplasia accompanied by collagen formation,obviously decreased skin appendages,infiltration of a few inflammatory cells in the dermis.AB-PAS staining was negative.The immunohistochemical study of pigmented patches showed positive staining for vimentin and Melan-A.The patient was pathologically diagnosed with metastatic myxoid melanoma with partial regression of the primary lesion.

Primary Malignant Fibrous Histiocytoma of the Chest Wall Misdiagnosed as Traumatic Hemothorax / 결핵및호흡기질환

Malignant fibrous histiocytoma (MFH), a type of sarcoma, is a malignant neoplasm with uncertain origins that arise from both the soft tissues and the bone. The occurrence of MFH on the chest wall is extremely rare. We hereby report a case of a 72-year-old woman who was incidentally detected with MFH after a traffic accident.

Atrophic dermatofibroma / Dermatofibroma atrofico

Dermatofibroma is a benign fibrohistiocytic tumor, common and easily diagnosed when classical clinicopathologic features are present. The atrophic variant of dermatofibroma is of uncertain origin. This lesion is characterized clinically by a flat or atrophic and depressible surface. Histopathological features show reduction of the thickness of the dermis and elastic fibers. We report a typical case of this uncommon and probably underdiagnosed variant.

O dermatofibroma é um tumor fibrohistiocitário benigno, comum e facilmente diagnosticado quando apresenta os achados clinicopatológicos clássicos. O dermatofibroma atrófico é uma variante específica do dermatofibroma, de origem ainda incerta. Esta é caracterizada clinicamente por lesão plana ou atrófica, depressível à compressão. Ao exame histopatológico, observa-se redução da espessura da derme e redução das fibras elásticas. Relatamos um caso típico desta variante incomum e provavelmente subdiagnosticada.

Primary Malignant Fibrous Histiocytoma of the Pleura / 결핵및호흡기질환

Malignant fibrous histiocytoma, a type of sarcoma, is a malignant neoplasm with uncertain origin that arises in both the soft tissues and the bone. The occurrence of primary malignant fibrous histiocytoma of the pleura is extremely rare. We report a case of a 65-year-old Korean man who is being diagnosed with primary malignant fibrous histiocytoma of the pleura.

Tomografia por emissão de pósitrons com 18F fluordesoxiglicose como exame não invasivo para o diagnóstico de sarcomas primários de artéria pulmonar / 18F-fluorodeoxyglucose positron emission tomography as a noninvasive method for the diagnosis of primary pulmonary artery sarcoma

Os sarcomas de artéria pulmonar são tumores raros e de difícil diagnóstico, simulando frequentemente o tromboembolismo pulmonar crônico. Relatamos dois casos de pacientes do sexo feminino com quadro clínico de dispneia e massas pulmonares associadas a falhas de enchimento na artéria pulmonar em angiotomografia de tórax. A tomografia por emissão de pósitrons com 18F fluordesoxiglicose mostrou hipercaptação das respectivas lesões. O sarcoma de artéria pulmonar foi confirmado posteriormente por exame anatomopatológico. Ressaltamos a importância do uso desse tipo de tomografia como exame não invasivo no auxílio diagnóstico desses tumores.

Pulmonary artery sarcomas are rare, difficult-to-diagnose tumors that frequently mimic chronic pulmonary thromboembolism. We report the cases of two female patients with clinical signs of dyspnea and lung masses associated with pulmonary artery filling defects on chest CT angiography. We performed 18F-fluorodeoxyglucose positron emission tomography, which revealed increased radiotracer uptake in those lesions. Pulmonary artery sarcoma was subsequently confirmed by anatomopathological examination. We emphasize the importance of this type of tomography as a noninvasive method for the diagnosis of these tumors.

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.

Malignant Fibrous Histiocytoma Arising in a Mature Cystic Teratoma of the Ovary: A Case Report

A 50-year-old female patient presented with anorexia and weight loss. Pelvic computed tomography revealed a 12.5 x 7.3 cm heterogeneous mass in the left ovary. About 30% of the tumor was occupied by a mature cystic teratoma. The remaining solid portion was composed of fibrous and histiocytic elements, arranged in storiform patterns admixed with bizarre giant cells. The mitotic index was 8 per 10 high power fields, including atypical mitoses. The only immunopositivity was for vimentin. The tumor was diagnosed as a malignant fibrous histiocytoma arising in a mature cystic teratoma. To the best of our knowledge, this is only the third such case in the English language literature.

Postradiation Malignant Fibrous Histiocytoma of the Colon: A Case Report

Post-radiation soft tissue sarcomas are recognized as rare complications of radiation therapy. The most common type of post-radiation soft tissue sarcoma is a malignant fibrous histiocytoma (MFH), which originates from mesenchymal cells with a predominance of histiocytes and fibroblasts. The two most common sites of occurrence for post-radiation soft tissue sarcomas are the chest wall and pelvic cavity. Post-radiation colorectal MFHs are extremely rare and all of the reported cases of post-radiation sarcomas have occurred >3 years after radiation therapy. Recently, we managed a case of colorectal MFH which developed in a 48-year-old male who had undergone a low anterior resection for rectal adenocarcinoma and had received chemoradiotherapy as adjuvant treatment. Twelve months after radiotherapy, a 4 cm mass was detected 8 cm superior to the anastomosis site on colonoscopic examination. A soft tissue sarcoma was suspected on pathologic examination of the biopsy specimen. Therefore, he underwent a Hartmann's operation and the final pathologic finding revealed MFH with a storiform pattern of tumor cells composed of pleomorphic, multinucleated giant cells. This is the first case of MFH that had a latency period <3 years (i.e., 1 year) between the time of radiotherapy and diagnosis.

Postradiation Malignant Fibrous Histiocytoma of the Colon: A Case Report

Post-radiation soft tissue sarcomas are recognized as rare complications of radiation therapy. The most common type of post-radiation soft tissue sarcoma is a malignant fibrous histiocytoma (MFH), which originates from mesenchymal cells with a predominance of histiocytes and fibroblasts. The two most common sites of occurrence for post-radiation soft tissue sarcomas are the chest wall and pelvic cavity. Post-radiation colorectal MFHs are extremely rare and all of the reported cases of post-radiation sarcomas have occurred >3 years after radiation therapy. Recently, we managed a case of colorectal MFH which developed in a 48-year-old male who had undergone a low anterior resection for rectal adenocarcinoma and had received chemoradiotherapy as adjuvant treatment. Twelve months after radiotherapy, a 4 cm mass was detected 8 cm superior to the anastomosis site on colonoscopic examination. A soft tissue sarcoma was suspected on pathologic examination of the biopsy specimen. Therefore, he underwent a Hartmann's operation and the final pathologic finding revealed MFH with a storiform pattern of tumor cells composed of pleomorphic, multinucleated giant cells. This is the first case of MFH that had a latency period <3 years (i.e., 1 year) between the time of radiotherapy and diagnosis.

Characteristics of spiral computed tomography imaging of primary hepatic malignant fibrous histiocytoma / 中华消化外科杂志

Primary hepatic malignant fibrous histiocytoma(PHMFH)remains extremely rare with less than 60 cases reported in literature.From October 1999 to May 2008,5 patients with PHMFH had been admitted to Yantai Cancer Hospital,Yantai Yuhuangding Hospital and the First Affiliated Hospital of Wenzhou Medical College,and the results of spiral CT were analyzed.Six tumors were detected,and the maximum diameter of the tumors was more than 8.5 cm.CT plain scanning revealed that all tumors were hypodense,4 patients with tumor necrosis and cystic degeneration,and the tumor in 1 patient wag with homogen density.Enhanced CT scanning showed marked enhancement of the solid component of tumor in 4 patients,slight enhancement in 1 patient,and a"fast in and fast out"sign in 5 patients.Hepatic bile ducts and portal vein were not involved.One patient was with portal lymph node metastasis and 1 with ioferior vena cava involvement.The characteristics of spiral CT imaging of PHMFH include tumor necrosis,cystis and invasion,as well as"fast in and fast out"sign,which could help to diagnose,although the ultimate diagnosis depends on histopathological examination.

Dermatofibroma aneurismático / Aneurysmatic dermatofibroma

Apresenta-se caso clínico de variante rara de dermatofibroma (tipo aneurismático) em paciente do sexo feminino de 72 anos de idade, cuja lesão se localizava na dobra flexural do membro superior direito, resultante de proliferação mesenquimal associada à vasos sanguíneos e hemorragia tecidual, com características histológicas próprias e bem definidas. Os objetivos desta descrição foram a raridade da lesão e a importância que ela assume, do ponto de vista histopatológico, quando comparada no diagnóstico diferencial com outros tumores benignos e malignos e a terminologia utilizada atualmente.

Primary malignancy in giant cell tumor: a case report / Malignização primária no tumor de células gigantes: um estudo de caso

Context: Primary malignancy in giant cell tumor (PMGCT) is rare. It is defined as a high-grade sarcoma originating in a giant cell tumor (GCT) and seems to behave less aggressively than its secondary counterpart does. Case report: This report presents the case of a 39-year-old female with pain in her left shoulder for one month. Radiography showed a pathological fracture of the proximal humerus associated with an osteolytic lesion. Histopathological analysis showed typical areas of GCT juxtaposed with a sarcomatous component. Conclusions: PMGCT seems to behave less aggressively than secondary malignancy in GCT, and it may simulate its more common benign counterpart clinically and radiographically. However, it requires a more aggressive type of treatment.

Contexto: Malignização primária no tumor de células gigantes (MPTCG) é rara. Ela é definida como um sarcoma de alto grau originário de um tumor de células gigantes que parece ser menos agressivo que o tipo secundário. Relato de Caso: Relatamos um caso de uma paciente de 39 anos de idade, com dor no ombro esquerdo há um mês. A radiografia mostrou uma fratura patológica do úmero proximal associada a uma lesão osteolítica. O exame histopatológico revelou típicas áreas de tumor de células gigantes justapostas por um componente sarcomatoso. Conclusão: MPTCG parece se comportar menos agressivamente que a neoplasia secundária do tumor de células gigantes (TCG), e pode simular o TCG, que é mais comum, tanto clínica como radiograficamente. Entretanto, exige tratamento mais agressivo.

Fibro-histiocitoma maligno da pálpebra: relato de caso / Malignant fibrous histiocytoma of the eyelid: case report

Os fibro-histiocitomas representam 1 por cento das massas orbitárias e podem ser histologicamente classificados em benignos, localmente agressivos e malignos - os últimos representando aproximadamente 11 por cento do total. Nesse estudo, os autores descrevem um caso raro de fibro-histiocitoma maligno de pálpebra, ressaltando as características clínicas e histopatológicas desta neoplasia.

Fibrous histiocytomas represent 1 percent of all orbital masses and may be classified into benign, locally aggressive and malignant - these representing nearly 11 percent of the total. In this study, the authors describe an unusual case of malignant fibrous histiocytoma of the eyelid, discussing clinical and histological features of this neoplasm.

Reassessment of the pathological diagnosis in 33 cases of malignant fibrous histiocytoma / 北京大学学报(医学版)

Objective:Since malignant fibrous histiocytoma (MFH) may be taken as an undifferentia-ted pleomorphic sarcoma (UPS), this study was conducted to reassess 33 previously diagnosed MFH cases in the past 10 years based on the latest WHO concept. And then to search for the clinicopathological features, probably tumorigenesis, and the line of differentiation of the remaining MFH/UPS cases.Methods: Thirty-three cases in tissue microarray were studied by immunohistochemistry with panels of neurogenic, myogenic, and lipogenic antibodies. Three expertise pathologists reevaluated the slides separately. Results: Among the 33 cases, 17 cases (51.5%) of MFH had their diagnoses changed, including 5 leiomyosarcomas, 3 malignant peripheral nerve sheath tumors, 1 fibrosarcoma, 1 inflammatory myofibrosarcoma, 1 giant cell tumor and 1 angiomatoid fibrous histiocytoma. The remaining 16 cases (48.5%) were finally diagnosed as MFH/UPS, among which patients were mainly old adults (median age: 63 years; range: 38 to 76 years). The median tumor size was 6.0 cm (range: 3.0 to 14.0 cm), 8 cases (50%) located in lower limb and 5 cases (31.3%) located in thigh. These tumors had marked cytological and nuclear pleomorphism. Immunohistochemistry showed that Vimentin was strongly positive in all 16 MFH/UPS (100%), Muscle-specific actin was variously positive in 8 cases (50%) and 1 case focally expressed Desmin. Eleven cases (68.8%) variously expressed CD68 (KP1) and 7 cases (43.8%) expressed CD68 (PG-M1), which were much higher than leiomyosarcoma, malignant peripheral nerve sheath tumor and liposarcoma with significant difference. Moreover, Ki67 expression rates were from 10% to 100%, including 14 cases more than 50% and 11 cases more than 70%. However, only 2 cases (12.5%) showed P53 positive. Conclusion: MFH/UPS often show marked histological pleomorphism, and the diagnosis must be made by exclusion of other definitive sarcomas, especially myogenic and neurogenic sarcoma. Only Vimentin was always expressed in MFH/UPS, while some of the tumors were positive for myogenic antigen and CD68. It was suggested that MFH/UPS might arise from primary mesenchymal cells, and some cases exhibited fibroblastic and/or myofibroblastic features. In addition, histiocytic phenotypic marker did have more expression in MFH/UPS than in other sarcomas. MFH/UPS still had certain clinicopathological characteristics.