1/9. Myofibrosarcoma (low-grade myofibroblastic sarcoma) with intracytoplasmic hyaline (fibroma-like) inclusion bodies.Myofibrosarcoma is a controversial neoplasm composed of cells with differentiation toward myofibroblasts. The authors report an unusual case of myofibrosarcoma in which, in addition to the characteristic features reported, tumor cells contained intracytoplasmic hyaline (fibroma-like) inclusion bodies. A 66-year-old man complained of a painless enlarged mass in his right shoulder over the previous 6 months. The tumor recurred 2 years after operation. On histologic examination, the tumor displayed diffusely infiltrative growth with isolation of individual skeletal muscle fibers. The tumor cells were most often arranged in an intersecting (herringbone) fascicular pattern but a vaguely storiform pattern was also observed. Cellularity varied from one area to another. The cells were spindle-shaped, with ill-define pale eosinophilic cytoplasm, and a wavy or tapering nucleus with fine chromatin and small nucleoli. Intracytoplasmic hyaline inclusion bodies of variable size, often located adjacent to the nucleus, were visible in numerous spindle and stellate cells. The mitotic index was 3/10 HPF. The tumor was scored as grade 1. immunohistochemistry revealed positive staining to muscle-specific actin, desmin and vimentin in most tumor cells. Intracytoplasmic hyaline inclusion bodies did not react specifically to any one antibody, but showed a marked ring-like immune reaction, particularly to muscle-specific actin. Electron microscopy showed tumor cells with indented nuclei and small nucleoli, abundant rough endoplasmic reticulum, micropinocytotic vesicles, and longitudinally arranged fine filaments with focal electron-dense patches and subplasmalemmal plaques. The most striking feature was the presence of large, globular or ball-like, non-membrane-bound, randomly scattered clusters of fine filament, usually adjacent to the nucleus.- - - - - - - - - - ranking = 1keywords = spindle, cell (Clic here for more details about this article) |
2/9. Fibroblastic/myofibroblastic sarcoma of the skin: a report of five cases.BACKGROUND: A number of malignant soft tissue tumors, particularly those of fibroblastic and fibrohistiocytic derivation, have been found to display myofibroblastic differentiation focally. The term myofibroblastic sarcoma, a controversial presumably distinctive entity, defines a malignant soft tissue tumor in which myofibroblasts are quantitatively the predominant cell type. methods: Five cases of cutaneous spindle-cell sarcomas showing fibroblastic-myofibroblastic differentiation with predominance of fibroblasts were retrieved from the files of three large centers of dermatopathology. Tumors were analyzed histopathologically, immunophenotypically, and, in two cases, ultrastructurally. Results were compared with those previously reported in fibrosarcoma, malignant fibrous histiocytoma, and myofibroblastic sarcoma. RESULTS: Immunophenotypic and ultrastructural profiles of the cases analyzed in this series were closer to fibrosarcoma and to malignant fibrous histiocytoma than to myofibroblastic sarcoma by virtue of quantitative predominance of fibroblasts over myofibroblasts. On the other hand, histopathologic findings were in keeping with those reported in myofibroblastic sarcoma. CONCLUSIONS: Our series highlights the intrinsic problems in attaching certain cutaneous sarcomas with fibroblastic-myofibroblastic differentiation to one of the recognized entities and gives support to the hypothesis that fibrosarcoma, malignant fibrous histiocytoma, and myofibroblastic sarcoma are related histogenetically.- - - - - - - - - - ranking = 0.4808465007762keywords = spindle, cell (Clic here for more details about this article) |
3/9. myofibromatosis-like hemangiopericytoma metastasizing as differentiated vascular smooth-muscle and myosarcoma. Myopericytes as a subset of "myofibroblasts".A thyroid hemangiopericytoma that was resected in a 5-year-old boy recurred insidiously in the larynx 8 years later. Marked cicatricial mucosal inflammation prevented a definitive pathologic diagnosis of recurrence until a nodule grew to obstruct the airway 15 years after initial surgery. After excision of the nodule, a larger sarcomatous metastasis was discovered in the upper esophagus and resected, but the patient eventually succumbed to widespread disease at the age of 20 years. The original tumor contained atypical pericytes and bundles of hyalinizing smooth muscle abutting on "staghorn vessels," a pattern similar to infantile myofibromatosis. desmin immunostaining was negative in the pericytes but positive in smooth-muscle cells dispersed singly as well as in bundles. Both elements reacted strongly for vimentin and the alpha-isoform of actin (alpha-SMA) found in normal smooth muscle and pericytes. A third cell type showing dendritic processes and immunoreactivity for all three antigens was interpreted as a myopericyte. Spindled cells in multiple subsequent mucosal biopsy specimens stained retrospectively also positive for these antigens. Large bundles of vascular smooth muscle surrounded by radiating myocytes characterized the occluding laryngeal nodule. In the esophageal metastasis, which showed no histologic features typical of hemangiopericytoma, numerous mitotically active, small, vimentin , desmin , alpha-SMA cells often maintained shortened processes and tended to form nodular aggregates about capillaries. Single rows of pericytes accreted to endothelial tubes. Ultrastructurally, some cells contained myofilaments and irregular dense material or showed rare cell junctions and variable investment by a basal lamina.(ABSTRACT TRUNCATED AT 250 WORDS)- - - - - - - - - - ranking = 0.076613996895219keywords = cell (Clic here for more details about this article) |
4/9. Low-grade myofibroblastic sarcoma of the vulva.BACKGROUND: Vulvar sarcomas are rare tumors. A distinctive low-grade myofibroblastic sarcoma is described. CASE: A 46-year-old female presented with a progressively enlarging vulvar mass. Pathological evaluation revealed a low-grade myofibroblastic sarcoma. The immunophenotype is outlined and ultrastructural features are highlighted. Tumor cells were positive for p53 protein, smooth muscle actin, steroid receptors, and showed myofibroblastic differentiation on electron microscopy. The patient has been followed for >14 months without evidence of recurrence. CONCLUSION: The tumor was positive for p53, mitotically active, but was categorized as a low-grade malignancy. Immunohistochemical and ultrastructural criteria were utilized to distinguish this tumor from other neoplasms.- - - - - - - - - - ranking = 0.012768999482537keywords = cell (Clic here for more details about this article) |
5/9. Myofibrosarcoma of the nasal bone.Myofibrosarcoma is a recently recognized rare tumor that mainly occurs in adults. These tumors are composed of a collagenous stroma and pleomorphic stellate to spindle-shaped cells that resemble smooth muscle cells with eosinophilic cytoplasm and tapered nuclei. We present a case of myofibrosarcoma of the nasal bones in a 4-year-old girl who showed rapid enlargement of a painless glabellar swelling. Computed tomography and magnetic resonance imaging revealed an expanding solid mass with erosion of the surrounding nasal bones. After excision and histopathological examination, this tumor was identified as a myofibrosarcoma. This is the first report of such a tumor localized to the glabellar region. This case report contributes to better awareness of an extremely rare type of glabellar lesion in children.- - - - - - - - - - ranking = 0.4808465007762keywords = spindle, cell (Clic here for more details about this article) |
6/9. Unusual sarcomatoid neoplasm of the lung suggesting a myofibrosarcoma.Myofibrosarcoma is a rare neoplasm that occurs mainly in the head and neck region and extremities of middle-aged patients. It often appears as a low-grade sarcoma and rarely metastasizes. We report the case of a 47-year-old male patient with a malignant mesenchymal pulmonary tumor affecting almost the entire lower left lobe. Clinically suggestive for a lung carcinoma, the tumor showed typical features of a myofibrosarcoma. A major spindle cell component was observed being positive for smooth-muscle actin, calponin, and vimentin, while stainings for desmin, h-caldesmon, alkaline phosphatase (ALK), and extensively studied cytokeratins were negative. Striking was a strong infiltrate with neutrophilic and eosinophilic granulocytes. dna cytometry revealed aneuploidy with a peak in the near triploid range. comparative genomic hybridization demonstrated multiple dna gains and losses correlating with an aggressive clinical course. Shortly after resection of the primary tumor, the patient showed multiple distant metastases in the contralateral lung, the mediastinal lymph nodes, the left adrenal gland, and the pectoral and deltoid muscle, which responded well to chemotherapy. The case report will discuss the evidence for the final diagnosis of a primary pulmonary myofibrosarcoma and the differential diagnosis of sarcomatoid tumors of the lung.- - - - - - - - - - ranking = 1.5971066534669keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
7/9. Stent fabrication for graft immobilization following wide surgical excision of myofibroblastic sarcoma of the buccal mucosa: a clinical report.Sarcomas of the head and neck are rare tumors derived from cells of mesenchymal origin. This article briefly discusses the epidemiology, etiology, and classification of head and neck sarcomas. Emphasis is placed on myofibrosarcoma, a malignant tumor of the myofibroblasts. Histologic criteria, prognostic factors, and the multidisciplinary management of these tumors are reviewed. A situation of a surgically excised myofibrosarcoma of the buccal mucosa is reported. In this patient, a stent was fabricated to stabilize a split-thickness skin graft used for the buccal mucosa reconstruction.- - - - - - - - - - ranking = 0.012768999482537keywords = cell (Clic here for more details about this article) |
8/9. leiomyosarcoma versus myofibrosarcoma: observations and terminology.Two spindle cell sarcomas, which showed similarities in light microscopic histology and immunostaining and were diagnosed as leiomyosarcomas by these criteria, were compared ultrastructurally to show the value of electron microscopy in subtyping these neoplasms. Both were subcutaneous, case 1 occurring in the nasolabial fold and case 2 in the upper calf. Both consisted of fascicles of spindle cells, and both stained positively for vimentin and alpha-smooth muscle actin; only case 2 stained additionally for desmin. Case 1 showed strong and case 2 weak or negative staining for fibronectin. By electron microscopy, case 1 contained prominent rough endoplasmic reticulum, peripheral fine filaments with focal densities, and fibronexus junctions. By contrast, case 2 was characterized by an external lamina and well-developed bundles of fine filaments with focal densities. Case 2 was considered a typical leiomyosarcoma, and case 1 was interpreted as showing myofibroblastic differentiation. The nomenclature for these myofibroblastic tumors is discussed, and myofibrosarcoma and leiomyosarcoma, myofibroblastic variant are suggested as suitable terms.- - - - - - - - - - ranking = 3.1942133069338keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
9/9. Low-grade myofibroblastic sarcoma: analysis of 18 cases in the spectrum of myofibroblastic tumors.The clinicopathologic, immunohistochemical, and ultrastructural features of a seemingly distinctive low-grade spindle cell sarcoma showing myofibroblastic differentiation have been analyzed in a series of 18 patients. The age range of the patients (7 women and 11 men) was 19-72 years (median: 42 years). A painless, enlarging mass was the most common clinical presentation. Five tumors arose in the oral cavity (including four lesions in the tongue), four in the lower extremities and three in the upper extremities, four cases in the abdominal/pelvic cavity, and two on the trunk. Eight soft-tissue cases involved skeletal muscle, three cases were located in perifascial tissues, and two arose in subcutaneous tissue. Tumor size ranged from 1.4 to 17 cm (median: 4 cm); in six cases (of which four were abdominal/pelvic) the lesion was larger than 5 cm. All patients were treated surgically, and four received additional adjunctive therapy. Histologically, most cases were cellular lesions showing a diffusely infiltrative pattern, and were composed of spindle-shaped tumor cells arranged mainly in fascicles. Tumor cells had poorly defined, palely eosinophilic cytoplasm and fusiform nuclei, which were either tapering and wavy or plumper and vesicular with indentations and small inconspicuous nucleoli. Tumor cells were set in a collagenous matrix often with prominent hyalinization. Mild nuclear atypia was noted in 16 cases; in the other 2 cases, and in the metastases of one other lesion, a greater degree of nuclear atypia was seen. In all but one case, the mitotic rate ranged from 1 to 6 mitoses in 10 HPFs (mean: 2/10 HPFs); in a single case, there were more than 20 mitoses in 10 HPFs. Immunohistochemically, all cases stained positively for at least one myogenic marker; 12 cases were positive for desmin, 11 for alpha-smooth muscle actin, and 6 for muscle actin (HHF35). Seven neoplasms were desmin positive/ alpha-smooth-muscle actin negative, and five cases were desmin negative/alpha-smooth-muscle actin positive emphasizing the variable immunophenotype of myofibroblastic lesions. In addition, 7 of 10 tumors stained at least focally positive for fibronectin. Ultrastructural examination in five cases showed characteristic features of myofibroblasts. Follow-up in 11 patients (median: 29 months) revealed local recurrence in 2 cases, and multiple distant soft-tissue, intraosseous, and pulmonary metastases in one other patient. Low-grade myofibroblastic sarcoma seems to represent a distinct entity in the spectrum of low-grade myofibroblastic neoplasms and is distinguishable from fibromatosis, myofibromatosis, solitary fibrous tumor, fibrosarcoma, and leiomyosarcoma.- - - - - - - - - - ranking = 2.1034911532082keywords = spindle cell, spindle, cell (Clic here for more details about this article) |