1/348. 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. ( info) |
2/348. 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. ( info) |
3/348. Male breast myofibroblastoma and MR findings. Myofibroblastoma of the breast is a rare benign tumor seen predominantly in men in the sixth to seventh decades of life. We present a case of breast myofibroblastoma in a man and describe the mammographic, sonographic, and MR findings. ( info) |
4/348. Recurrent involvement of 2p23 in inflammatory myofibroblastic tumors. Inflammatory myofibroblastic tumor (IMT) is a relatively rare soft tissue tumor. The reactive versus neoplastic pathogenesis of this tumor is unresolved. We found clonal chromosome aberrations involving 2p23 upon metaphase analysis of two IMTs. fluorescence in situ hybridization with a probe flanking the ALK gene at 2p23 demonstrated rearrangement of the probe in both of these cases and in a third case, and immunohistochemistry revealed ALK expression in all three cases. 2p22-24 involvement has been reported previously in four additional cases of IMT. We suggest that chromosomal rearrangements involving 2p23 near or within ALK are recurrent alterations in IMT and that ALK may have a novel role outside its previously recognized realm of lymphoid neoplasms. ( info) |
5/348. 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. ( info) |
6/348. Surgical aspects of iliopsoas compartment tumours. AIM: To demonstrate the pathological variety and highlight the surgical principles involved in the management of tumours of the iliopsoas compartment (IPC). methods: review of four clinical cases. RESULTS: Adequate surgical resection or palliation was achieved in each case. CONCLUSION: Resection of IPC tumours is feasible but access to the most superior part of the muscle may be impossible. An extraperitoneal approach is advocated. ( info) |
7/348. Pediatric inflammatory bladder tumors: myofibroblastic and eosinophilic subtypes. PURPOSE: Benign bladder tumors are rare in children. A number of descriptive terms have previously been used to describe inflammatory tumors with myofibroblastic proliferation or eosinophilic infiltration. We present our experience with these tumors and review the literature. MATERIALS AND methods: We retrospectively reviewed the records of all children presenting with a benign focal bladder mass during the last 5 years, including 2 girls and 3 boys 2 to 12 years old (mean age 7). RESULTS: Presenting symptomatology included irritative voiding symptoms, suprapubic pain and hematuria. All bladder masses were diagnosed by ultrasonography and all patients underwent transurethral resection. Three children who had an inflammatory bladder tumor with myofibroblastic features required open tumor excision with preservation of the bladder. In the 2 remaining children urine culture was positive preoperatively and the diagnosis was an inflammatory bladder tumor with eosinophilic infiltration. Transurethral resection of the mass was performed without partial cystectomy. CONCLUSIONS: Inflammatory myofibroblastic and eosinophilic tumors represent forms of focal cystitis with a tumefactive component. Differentiation from the malignant bladder neoplasms of childhood has important consequences for therapy. Management of these benign but aggressive inflammatory lesions involves local control by endoscopic or open surgery with bladder preservation. We encourage refined use of the terminology for inflammatory myofibroblastic and eosinophilic tumors. ( info) |
8/348. 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. ( info) |
9/348. 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. ( info) |
10/348. 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. ( info) |