Pleomorphic lipoma. Case reports and review of the literature.

Two patients are reported with pleomorphic lipoma, a benign subcutaneous fatty tumor showing atypia in which histologic diagnosis may be difficult. The tumors are well circumscribed lesions, most commonly occurring in the neck and shoulder of middle aged men. An important histologic criteria is the presence of floret-like multinucleated giant cells embedded in a myxoid stroma. Pleomorphic lipoma may be confused with several malignant soft-tissue neoplasms, including myxoid malignant fibrous histiocytoma and variants of liposarcoma. It is important to establish the correct diagnosis to avoid unnecessary radical surgery.     

Atypical fibrous histiocytoma with myxoid stroma: a rare lesion arising from dura mater of the brain.

Intracranial fibrohistiocytic tumors are rare. This report is concerned with a 24-year-old white male who had an 8 month history of intermittent visual disturbance. Craniotomy revealed a large, completely intradural lesion on the floor of the left anterior cranial fossa without involvement of the leptomeninges or brain parenchyma. Gross and microscopic examination revealed that the fibrogenic portion of the tumor was composed of spindle shaped neoplastic cells arranged in storiform pattern, a hallmark of fibrohistiocytic tumor. In contrast to three previously reported cases of "fibrous xanthomas" involving the leptomeninges and superficial cortex of the brain, the present lesion is clearly originated from mesenchymal stem cell of the dura. The other distinct gross and microscopic feature was the presence of myxoid component which constituted about 40% of the entire lesion. The myxoid component had not been observed in previous 5 reported cases of intracranial fibrohistiocytic lesions. Since there was cellular pleomorphism with extremely rare mitosis, it was felt that the lesion be best designated as atypical fibrous histiocytoma with myxoid stroma.     

Malignant fibrous histiocytoma of the maxillary sinus. A case report.

We report a case of malignant fibrous histiocytoma of the left maxillary sinus in a 30 year-old man. The major problem encountered was the histological diagnosis of the first biopsy, which showed a non specific fasciculated, myxoid, alveolar pattern suggestive of a mesenchymal malignancy, thus preventing the correct diagnosis that became possible only when the surgical specimen was available.     

Primary Malignant Fibrous Histiocytoma of the Stomach: (A Case Report)

A case of primary malignant fibrous histiocytoma (MFH) of the stomach is reported. The patient was a 51-year-old man who had a laparotomy for a malignant gastric tumour diagnosed by radiological studies and endoscopic examination. An inoperable gastric malignancy was found at operation. Histopathological studies of tissue biopsied at surgery showed characteristic light microscopic findings and strong positivity for alpha-1-antitrypsin by immunoperoxidase technique indicating the diagnosis of malignant fibrous histiocytoma. The absence of any other soft tissue or retroperitoneal tumour strongly indicated the stomach is the primary site.     

腹膜后巨大恶性纤维组织细胞瘤误诊1例并文献复习

目的观察腹膜后恶性纤维组织细胞瘤的临床表现、病理形态及免疫组化特点，吸取误诊教训。方法通过对1例腹膜后恶性纤维组织细胞瘤的临床表现、光镜形态及多次免疫组化结果进行观察，明确诊断，并复习相关文献。结果恶性纤维组织细胞瘤多发于中老年男性。根据镜下所见及第一次免疫组化结果曾诊断为巨大恶性神经鞘膜瘤。后又经多次免疫组化结果S-100（-），NF（-），排除恶性神经鞘膜瘤的可能；经多次专家会诊及远程会诊，确诊为腹膜后巨大恶性纤维组织细胞瘤。结论原发性腹膜后恶性肿瘤比较多样化，因此他的确诊依赖于镜下形态和可靠的免疫组化结果，这些经验教训值得大家借鉴。     

原发性软组织恶性纤维组织细胞瘤的MRI影像诊断（附15例报告）

目的：探讨原发性软组织恶性纤维组织细胞瘤（MFH）的MRI影像诊断。方法：回顾性分析15例经手术病理证实的原发于软组织的恶性纤维组织细胞瘤患者的影像学资料,15例患者均行MRI检查,有7例行CT检查,8例行增强扫描。结果：原发于软组织恶性纤维组织细胞瘤15例,肿瘤形态多样,以卵圆形、分叶状多见。病变于T1WI呈低信号或等信号,T2WI呈高信号或等信号为主混杂信号影,7例病变内可见低信号之分隔影。13例病变内见坏死或黏液样改变,2例伴出血。明确有包膜3例。增强扫描均呈显著不均匀强化。结论：MRI对原发性软组织恶性纤维组织细胞瘤的诊断具有重要价值,是首选的影像学检查方法。     

低度恶性纤维黏液性肉瘤一例并文献复习

目的：分析低度恶性纤维黏液样肉瘤的临床病理特征及鉴别诊断。方法：对一例低度恶性纤维黏液样肉瘤进行大体、光镜及免疫组化观察并结合文献复习。结果：瘤细胞排列呈漩涡状,散布在富于血管的纤维黏液样间质中,黏液区与纤维区明显过渡。免疫组化肿瘤细胞SMA（-）、EMA（-）、S-100（-）、CD99（-）、CD68（-）。结论：低度恶性纤维黏液样肉瘤是g 种非常少见的软组织肿瘤,常被误诊为良性肿瘤,需与黏液样纤维肉瘤I级、黏液样神经纤维瘤、恶性纤维组织细胞瘤等鉴别诊断。     

Myxoid variant of malignant fibrous histiocytoma: ultrastructural observations.

The ultrastructural findings in 4 cases of the myxoid variant of malignant fibrous histiocytoma (MFH) are described. Although this neoplasm is characterized by a high rate of local recurrence, the overall prognosis is considerably better than the usual nonmyxoid MFH. The neoplasm is composed of an admixture of round, stellate and multinucleated giant cells within a myxoid and well-vascularized stroma. Electron microscopy demonstrated four principal cell types: a primitive mesenchymal cell, spindle cells of fibroblastic and histiocytic nature, and multinucleated giant cells. These observations complement the light microscopic features but probably are insufficient to differentiate critically this entity from other myxomatous lesions of mesenchymal soft tissue such as myxoma, pseudosarcomatous fasciitis, myxoid liposarcoma. The polymorphic cellular composition lends support to the concept that the neoplasm is probably derived from a primitive multipotent mesenchymal cell capable of structural and functional modulation toward more cytodifferentiated forms.     

Postirradiation malignant fibrous histiocytoma in a patient with squamous carcinoma of the uterine cervix--an autopsy case

An autopsy case of postirradiation sarcoma is described. The tumor, a malignant fibrous histiocytoma, occurred in the radiation fied 7 years after postoperative external beam radiation therapy (6000 rad) for squamous cell carcinoma of the cervix. To our knowledge, 11 cases of postirradiation malignant fibrous histiocytoma have been reported in the literature and only one occurrence of this neoplasm after treatment for cervical cancer has been described. We review the literature on postirradiation sarcoma with special attention to malignant fibrous histiocytoma.     

Postirradiation sarcoma (malignant fibrous histiocytoma) following cervix cancer

A case of postirradiation sarcoma is described. The tumor, a malignant fibrous histiocytoma, occurred in the radiation field 11 years following postoperative external beam radiation therapy (7000 rad) for carcinoma of the cervix. Reports of postirradiation malignant fibrous histiocytoma are rare, and the occurrence of this neoplasm following treatment of cervix cancer has not previously been described. The literature concerning postirradiation bone and soft tissue sarcomas is briefly reviewed, with special attention to malignant fibrous histiocytomas.     

Postirradiation sarcoma (malignant fibrous histiocytoma) of axilla.

A case is reported of a patient who developed a histologically unusual sarcoma in the axilla and chest wall 8 years after receiving radiation therapy (6500 rad) for carcinoma of the breast. This sarcoma showed light- and electron-microscopic features of a malignant fibrous histiocytoma, a tumor not documented among 24 previously reported cases of postirradiation sarcoma following the diagnosis of breast carcinoma. In addition, the literature is reviewed and discussed regarding postirradiation sarcoma in general following breast carcinoma.     

Aneurysmal ("angiomatoid") fibrous histiocytoma of the skin

Seventeen cases are reported of a variety of cutaneous fibrous histiocytoma, which we have designated as aneurysmal ("angiomatoid") fibrous histiocytoma. These lesions differ from the classical cutaneous fibrous histiocytoma in both their clinical presentation and pathologic features. Clinically, they may be larger than the usual cutaneous fibrous histiocytoma, are blue, black, or dark red, and have a cystic consistency. They are most commonly located on the extremities and may be associated with symptoms of pain and rapid growth. The clinical diagnosis of fibrous histiocytoma is seldom considered in the differential diagnosis, which may include malignant melanoma, hemangioma, neurofibroma, and nonspecific cyst. Histologically, the lesions are characterized by the presence of large, blood-filled tissue spaces, which, at times, account for up to one half their size. These spaces lack an endothelial lining, being surrounded and lined by histiocytes, many of which contain hemosiderin pigment, fibroblasts, and foam cells. The solid portions of the tumor have the usual features of a cutaneous fibrous histiocytoma. This "angiomatoid" lesion is closely allied to what has been termed "hemosiderin histiocytoma," which appears to be a precursor stage in its formation. The presence of extravasated erythrocytes in combination with a spindle-cell stroma may lead to an erroneous diagnosis of Kaposi's sarcoma. This cutaneous tumor has architectural and cytologic similarities to its malignant soft tissue counterpart recently described as angiomatoid malignant fibrous histiocytoma. However, unlike the latter, the cutaneous lesion is benign and lacks the prominent inflammatory infiltrate, pleomorphic appearance, and systemic manifestations of its soft tissue counterpart. The distinctive clinical and pathologic features of the cutaneous lesion serve to separate it as a specific variant of the cutaneous fibrous histiocytomas.     

Prognostic significance of histologic parameters of soft tissue sarcomas.

BACKGROUND AND METHODS. A univariate and multivariate analysis for the correlation between histomorphologic factors and prognosis was made using data from 1116 patients with soft tissue sarcoma, including 1005 cases available with complete histologic and follow-up data. RESULTS. The overall 5-year survival rate was 43.6%. The univariate analysis using Kaplan-Meier survival curves showed that tumor differentiation, cellularity, nuclear atypia, cellular pleomorphism, mitotic activity, amount of fibrous stroma, extent of myxoid areas, extent of tumor necrosis, and histologic grading (determined by the estimated range of malignancy for each type of sarcoma using a reported guideline) were all significant prognostic factors in the overall soft tissue sarcoma group. By a multivariate analysis using a procedure based on the Weibull model to failure data, the histologic grading and extent of tumor necrosis were proved to be prognostically significant in the overall sarcoma group. However, after additional analysis on each histologic type of sarcoma, it was determined that both tumor necrosis and histologic grading were applicable in only two types: malignant fibrous histiocytoma and leiomyosarcoma. Liposarcoma, synovial sarcoma, and malignant schwannoma each also showed some determinable factor of prognostic significance. CONCLUSIONS. It was concluded that there seemed to be no single universal prognostic parameter that could be applied to each soft tissue sarcoma type. These results suggest that the predictive significance of the various histologic parameters should be based on each specific type of sarcoma.     

Myxoid variant of malignant fibrous histiocytoma.

It has been generally recognized that malignant fibrous histiocytoma (MFH) may assume a highly myxoid, hypocellular appearance. Eighty cases of malignant fibrous histiocytoma having varying degrees of myxoid change were reviewed. These tumors typically arose on the extremities (leg, 61%; arm, 21%) of adults (peak age incidence, 60-69 years). They were usually attached to fascia (31%) or involved skeletal muscle (51%) and had a mucoid or translucent appearance. The myxoid areas consisted of widely spaced spindled and pleomorphic cells embedded in a matrix of acid mucopolysaccharides. The cellular areas were indistinguishable from those of the typical pleomorphic MFH. The rate of local recurrence of these tumors was 61%, and of metastasis, 23%, but metastasis was less likely when the tumor was small, superficially located, or had a prominent myxoid component. In fact, the degree of myxoid change was inversely related to the rate of metastasis. Therefore, because of the more favorable prognosis of the myxoid variant, it seems appropriate to separate it from the usual nonmyxoid form of MFH. The myxoid variant must also be clearly distinguished from benign myxoid lesions such as myxoma or nodular fasciitis, with which it is often confused.     

Pleomorphic liposarcoma of a young woman following radiotherapy for epithelioid sarcoma

A case of a metachronous epithelioid sarcoma and pleomorphic liposarcoma in a young woman is described. The first tumor was an epithelioid sarcoma (ES) with focal rhabdoid features localised in the left calf while the second lesion developed seven years later in the same region was diagnosed as pleomorphic liposarcoma resembling myxofibrosarcoma ( myxoid variant of malignant fibrous histiocytoma ) predominantly composed of moderately differentiated spindle cells. Multiple foci of uni- and plurivacuolated lipoblasts were seen. Following the resection of ES the patient received 57 Gy radiation to the region, therefore we regarded the second tumor as a radiation induced liposarcoma. A further interesting feature of this case is that the development of pleomorphic liposarcoma preceded by 6 months the solitary right parabronchial metastasis of ES and after 4 months of metastasectomy a third tumor developed at the site of the first lesion. This tumor showed dedifferentiation toward pleomorphic malignant fibrous histiocytoma. Our case represents a unique case of postirradiation liposarcoma developed on the base of ES.     

黏液性血管瘤样纤维组织细胞瘤临床病理和分子遗传学特征

目的探讨黏液性血管瘤样纤维组织细胞瘤(MAFH)的临床病理特征、免疫表型和分子遗传学特征及其诊断和鉴别诊断要点。方法收集2015年1月至2018年8月间就诊于浙江省人民医院的3例MAFH患者的临床资料,分析其临床和影像学特征、组织形态学、免疫表型、分子遗传学特征以及患者的预后。结果3例患者中,男1例,女2例;年龄分别为37岁、46岁和57岁。临床上均表现为缓慢增大的无痛性肿物,病史分别为2周、2个月和50年。3例患者的肿瘤均位于肢体或肢端的深部软组织内(右髋部、左前臂和左腕部各1例),2例术前影像学考虑为腱鞘囊肿或腱鞘巨细胞瘤。肿瘤直径3.0~7.5 cm,大体界限清楚,切面灰白、灰褐,有黏质感,2例可见不同程度的出血、囊性变。低倍镜下观察,3例均可见厚的纤维性假包膜伴包膜周围的淋巴浆细胞袖套,以多结节状或分叶状生长为主,2例可见明显的出血性囊腔形成。黏液性肿瘤区域分别占60.0%、80.0%和90.0%,瘤细胞卵圆形至星芒状,呈条索状、微囊状和网状分布于丰富的黏液性基质之中。3例均可见黏液性肿瘤成分过渡为局灶典型的非黏液性血管瘤样纤维组织细胞瘤(AFH)组织学形态。瘤细胞异型性轻微,核分裂象稀少(每50倍高倍视野1~2个),未见肿瘤性坏死,1例可见局灶明显的细胞质内空泡。免疫组化染色显示,2例局灶表达结蛋白,2例局灶表达上皮膜抗原,1例局灶表达CD99,Ki67阳性指数1%~5%。荧光原位杂交检测3例均存在EWSR1基因重排。1例术后随访15个月复发;1例第1次术后24个月复发,复发的肿瘤缓慢增大,120个月后第2次切除,再随访2个月未见复发和转移;1例术后32个月未见复发和转移。结论MAFH是一种罕见的AFH组织学亚型,生物学行为低度恶性,形态学上易于误诊。仔细观察寻找典型的AFH组织学特点、并辅以EWSR1基因的重排检测可助于MAFH的诊断和鉴别诊断。     

The value of fine-needle aspiration biopsy in the differential diagnosis of adult myxoid sarcoma

BACKGROUND: The usefulness of fine-needle aspiration biopsy (FNAB) for the histologic subtyping of specific sarcomas still is somewhat controversial but is becoming increasingly popular in the U.S. METHODS: To determine the accuracy and usefulness of FNAB in the differential diagnosis of myxoid sarcoma, the authors retrospectively reviewed 18 FNAB specimens (16 primary tumors, 1 local recurrence, and 1 metastasis) in 18 patients. The study sample included myxoid/round cell liposarcoma in six patients, myxofibrosarcoma in six patients, myxoid chondrosarcoma in five patients, and myxoid leiomyosarcoma in one patient. RESULTS: All but one tumor were recognized correctly as malignant. With regard to primary tumors, a specific cytologic diagnosis was rendered in 13 of 16 patients (81%). Problematic areas included the diagnosis of high grade myxofibrosarcoma with minimal amounts of myxoid stroma, myxoid liposarcoma with a predominant round cell component, and the single case of myxoid leiomyosarcoma. CONCLUSIONS: FNAB represents a valuable diagnostic tool for the differential diagnosis of myxoid sarcoma, especially myxofibrosarcoma, low grade myxoid liposarcoma, and myxoid chondrosarcoma. Due to its prognostic and therapeutic significance, the presence of a predominant round cell component in myxoid liposarcoma should be documented adequately. Other sarcomas (e.g., leiomyosarcoma) rarely may exhibit a prominent myxoid stroma and therefore should be considered in the differential diagnosis of adult myxoid sarcoma.