1/278. Recurrent intranodal palisaded myofibroblastoma with metaplastic bone formation.Intranodal palisaded myofibroblastoma (IPM) is a rare primary nonlymphoid tumor of the lymph node, which can easily be mistaken for other spindle cell tumors. Intranodal palisaded myofibroblastoma is thought to arise from intranodal myofibroblasts, a finding that is supported by its immunophenotype, positive immunostaining for actin and vimentin, and negative immunostaining for desmin. Characterized by a benign clinical course, IPM is treated by simple surgical excision. We describe a 49-year-woman, who had cadaveric renal transplantation in 1992 and recurrent IPM 41/2 years after its original excision. To our knowledge, this case represents only the second known case of recurrent IPM. The histologic feature of metaplastic bone formation in this case has not been previously described in IPM.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
2/278. Myofibroblastoma of the breast with hemangiopericytoma-like pattern and pleomorphic lipoma-like areas. Report of a case with diagnostic and histogenetic considerations.Myofibroblastoma (MFB) of the breast is an uncommon benign spindle cell tumor which may exhibit a wide spectrum of histological features. We report an unusual case of MFB of the male breast, showing cellular areas with a hemangiopericytoma-like pattern similar to that observed in solitary fibrous tumor (SFT) and extensive fibromyxoid areas containing numerous atypical stromal cells. The association of these atypical cells with mature adipocytes and microcystic and/or myxoid degenerative changes resembled pleomorphic lipoma-like and myxoid liposarcoma-like features, respectively. To our knowledge, these peculiar morphological findings have not been previously reported in MFB of the breast. They should be recognized to avoid confusion with other mesenchymal tumors, especially with hemangiopericytoma, pleomorphic lipoma (PL), spindle-cell lipoma (SCL) and myxoid liposarcoma. A case of MFB of the breast showing morphological features also commonly seen in SFT and PL/SCL is further morphological evidence in support of the speculation that the mesenchymal tumors of the breast, also known under the terms benign spindle cell tumors, fibromas, SFTs, SCLs and MFBs, are histogenetically related lesions.- - - - - - - - - - ranking = 2.3841846767716keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
3/278. Myofibroblastoma of the breast with diverse histological features.We report two cases of myofibroblastoma with unusual pathological features, in a 66-year-old woman and a 49-year-old man. Both tumours were unilateral, grossly nodular and well circumscribed, but not encapsulated. The lesions were made up of bipolar spindle cells arranged in fascicular clusters separated by bands of hialinized collagen; one included several islands of mature cartilage next to fat cells. The other contained atypical mononucleated and multinucleated giant cells. No mitotic figures were observed. Immunohistochemically, both tumours showed strong and diffuse cytoplasmic staining for vimentin and CD 34 and focal positivity for alpha-smooth muscle actin, and both were negative for cytokeratins, CD 68, Ham 5, 6, Mac 387, and S-100 protein. desmin was positive in one case. Ultrastructural study revealed populations composed of fibroblastic cells without signs of myofibroblastic differentiation in one case; the second featured abundant undifferentiated mesenchymal cells with myofibroblastic differentiation. Both patients remain disease-free 38 and 36 months after lumpectomy.- - - - - - - - - - ranking = 1.1673731203341keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
4/278. Myofibroblastoma of the ovary: report of a case.We report an unusual case of an ovarian tumor arising in a 22-year-old female that showed histologic, immunohistochemical, and ultrastructural features of myofibroblastic differentiation. The mass was found incidentally and upon excision was 9.0 cm in its greatest dimension and almost entirely replaced the left ovary. The patient is alive without evidence of disease 21 months after excision. Histologically, the tumor was encapsulated and composed of cytologically bland spindled cells arranged into a variety of patterns, similar to those found in both solitary fibrous tumor and hemangiopericytoma. Immunohistochemically, the cells stained strongly for smooth muscle actin and muscle-specific actin, with only focal and weak staining for CD34. Stains for S-100 protein, desmin, and AE1/AE3 were negative. Ultrastructurally, the neoplastic cells showed clear-cut evidence of myofibroblastic differentiation. The differential diagnostic considerations, including solitary fibrous tumor and hemangiopericytoma, are discussed.- - - - - - - - - - ranking = 0.34234139668808keywords = spindle, cell (Clic here for more details about this article) |
5/278. Myofibroblastoma of breast: evidence favoring smooth-muscle rather than myofibroblastic differentiation.A histopathological study of two cases of the tumor known in the literature as myofibroblastoma of the breast is presented. The tumors occurred in Caucasian males aged 57 and 62 years. Histologically, these were moderately cellular, lobulated spindle-cell lesions, each with a reasonably well-delineated edge with surrounding fatty connective tissue. No breast ducts or lobules were present. Tumor cell nuclei were bland, with small nucleoli and some nuclear grooving. Nuclear atypia and mitoses were absent. Immunostaining revealed positivity for a-smooth-muscle actin, desmin, and CD34. Tumor cells contained rough endoplasmic reticulum, bundles of myofilaments with focal densities, intermediate filaments, attachment plaques alternating with plasmalemmal caveolae, and focal lamina. Ultrastructural findings pointed to true smooth-muscle differentiation, and the cell-surface in particular lacked surface features of myofibroblasts (fibronectin fibrils [microtendons] and fibronexus junctions). These and published data suggest that at least some of the lesions referred to in the literature as myofibroblastoma may not be myofibroblastic and may be better designated as myogenic stromal tumors or as variants of leiomyoma.- - - - - - - - - - ranking = 0.42602795685513keywords = spindle, cell (Clic here for more details about this article) |
6/278. Myofibroblastic tumours: neoplasias with divergent behaviour. Ultrastructural and flow cytometric analysis.myofibroblasts are spindle cells having ultrastructural features in common with smooth muscle cells and fibroblasts. In the last few years, tumours have been described in which myofibroblasts represent not only a reactive mechanism but also a true neoplastic component. They constitute new nosologic entities which might be termed "myofibroblastic tumours". Tumours with benign and, rarely, malignant behaviour are reported to belong to this group of lesions. Recently, a third tumour type with borderline biological course, named "inflammatory myofibroblastic tumour" (IMT), has been identified, a condition that has been regarded as a benign and reactive disorder for a long time. Only in recent reports has been demonstrated that, in spite of an apparently benign morphological pattern, some cases of IMT have a malignant course. In this connection, dna analysis by flow cytometry is a valuable diagnostic tool, because it allows identification of the ploidy status, a procedure that is often useful for predicting the nature and the biological behaviour of the lesion. In this study, 11 cases of myofibroblastic tumours were examined retrospectively by evaluating clinicopathological features and dna ploidy status by flow cytometry. The diagnosis of myofibroblastic tumour was confirmed by performing histology, immunohistochemistry, and electron microscopy in all patients. In detail, these 11 cases were composed of 1 benign myofibroblastoma, 1 myofibrosarcoma and 9 IMTs. Among these myofibroblastic tumours, all those with local recurrence or distant metastases (one myofibrosarcoma and three IMT) showed an aneuploid cell population demonstrable by flow cytometric analysis, whereas the other cases with benign course (one benign myofibroblastoma and six IMT) exhibited an euploid dna content. These data suggest the following: a) Besides the rare myofibroblastomas and myofibrosarcomas, IMTs represent a larger group of lesions with potentially different biological and clinical course. b) dna flow cytometric analysis is a reliable tool that support histopathological examination in characterizing those cases of IMT that, though being malignant, mimic benign lesions. Consequently, it establishes the basis for a different therapeutic approach according to the euploid or aneuploid dna content.- - - - - - - - - - ranking = 1.083686560167keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
7/278. Sclerosing inflammatory myofibroblastic tumour of the tongue: an immunohistochemical and ultrastructural study.A case of inflammatory myofibroblastic tumour (IMT) arising in the tongue of a 27-year-old man is described. The patient presented with a solitary, well-circumscribed submucosal mass of 4 months duration. The tumour showed in its largest part a paucicellular sclerosing lesion resembling a hyalinizing granuloma surrounded by a thin rim of an admixture of myofibroblasts, plasma cells and foamy histiocytes. myofibroblasts expressed vimentin and alpha-smooth muscle actin positive immunophenotypes. Ultrastructurally the hyaline areas were composed of abundant collagen fibres with sparse myofibroblasts. Extensive scar-like change in this IMT may be related to a traumatic insult.- - - - - - - - - - ranking = 0.083686560167044keywords = cell (Clic here for more details about this article) |
8/278. Myofibroblastoma of the breast: genetic link with spindle cell lipoma.Mammary myofibroblastoma is a rare tumour, mainly occurring in male patients. This paper describes two cases of mammary myofibroblastoma, with typical histological features, including the presence of fat cells and mast cells. Immunohistochemically, the spindle cells stained positively for desmin and CD34. Cytogenetically, both tumours showed partial monosomy 13q and in case 1, there was, in addition, partial monosomy 16q. Rearrangements affecting 13q and 16q occur typically in spindle cell lipomas. In addition to histological similarities, the hitherto unreported chromosomal changes in mammary myofibroblastoma, which are similar to the chromosomal aberrations in spindle cell lipoma, strongly suggest a link between these two tumours and are not in favour of myofibroblastoma being a primary solitary fibrous tumour of the breast.- - - - - - - - - - ranking = 7.083686560167keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
9/278. Lipomatous myofibroblastoma: a potential diagnostic pitfall in the spectrum of the spindle cell lesions of the breast.We report on two cases of myofibroblastoma (MFB) of the breast comprised predominantly of a mature fatty component, representing approximately three quarters of the entire tumour area. Both tumours consisted of a well-circumscribed lipomatous tumour mass containing dispersed nodular or irregularly shaped spindled cellular areas. The fatty component was represented exclusively by mature adipocytes, uniform in size and shape, lacking nuclear pleomorphism. The cellular areas contained spindly to oval cells with morphological and immunophenotypical features typical of MFB. The two components were so intimately admixed that a finger-like infiltrating growth pattern was apparent. The cases reported here as "lipomatous MFB" aim to clarify further the morphological spectrum of MFB of the breast. Lipomatous MFB may potentially mimic other benign or aggressive tumour-like lesions or even bland-looking malignant spindle cell tumours such as fibromatosis, nodular fasciitis, spindle cell lipoma, spindle cell liposarcoma, spindle cell variant of metaplastic carcinoma, spindle cell malignant myoepithelioma, and low-grade fibrosarcoma/malignant fibrous histiocytoma. The histogenesis of the present bimorphic mesenchymal tumours could be explained as the result of a dual, myofibroblastic and lipomatous, differentiation from a common pluripotential mesenchymal precursor cell, probably represented by the vimentin /CD34 fibroblast of the mammary stroma.- - - - - - - - - - ranking = 9.3841846767716keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
10/278. Inflammatory myofibroblastic tumor involving the pterygopalatine fossa.SUMMARY: Inflammatory myofibroblastic tumors (IMT) comprise a rare group of lesions characterized histologically by acute and chronic inflammatory cells with a variable degree of fibrous stroma. Occurrence in the extracranial head and neck in children is unusual, and involvement in the pterygopalatine fossa has not, to our knowledge, been reported as occurring in this age group. We present the CT findings of an IMT of the pterygopalatine fossa in a 6-year-old female patient with a 2-week history of fever and a painless swelling of the left cheek. The diagnosis of IMT should be included in the differential diagnosis of a child presenting with an aggressive mass associated with systemic features such as fever, elevated sedimentation rate, and leukocytosis.- - - - - - - - - - ranking = 0.041843280083522keywords = cell (Clic here for more details about this article) |
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