1/38. Solitary fibrous tumor of the oral cavity: an uncommon location for a ubiquitous neoplasm.Solitary fibrous tumor is an uncommon soft tissue tumor initially reported in the pleura but recently described in other sites of the body. To date, only 5 examples of oral solitary fibrous tumor have been reported. Here, we describe 2 additional cases of this tumor in the oral cavity. The tumors were composed of small to medium-sized spindle cells with bland cytologic features; these cells were haphazardly arranged in highly cellular sheets or ill-formed fascicles as well as in hypocellular areas with hyalinized blood vessels. Both tumors contained blood vessels with a hemangiopericytomalike appearance and expressed vimentin, CD34, and CD99. One case was also strongly positive for bcl-2. The diagnosis of solitary fibrous tumor may be difficult inasmuch as it shares a number of histologic features with other soft tissue tumors. awareness of its occurrence in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided.- - - - - - - - - - ranking = 1keywords = hemangiopericytoma (Clic here for more details about this article) |
2/38. Fine-needle aspiration cytology of hemangiopericytoma: A report of five cases.BACKGROUND: hemangiopericytoma (HPC) is a relatively rare neoplasm, accounting for approximately 2.5% of all soft tissue tumors. Its histopathology has been well documented but to the authors' knowledge reports regarding its fine-needle aspiration (FNA) cytology rarely are encountered. In the current study the authors report the cytologic findings in FNA specimens from nine confirmed cases of HPC and attempt to correlate the cytologic features with the biologic outcomes. methods: FNA was performed with or without radiologic guidance. Corresponding sections of tissue were reviewed in conjunction with the cytologic preparations. RESULTS: Nine FNAs were performed in 5 patients (3 men and 2 women) with an age range of 38-77 years (mean, 56 years). Two lesions were primary soft tissue lesions arising in the lower extremities; seven were recurrent or metastatic lesions from bone (one lesion), kidney (one lesion), pelvic fossa (one lesion), lower extremities (two lesions), trunk (one lesion), and breast (one lesion). All aspirates were cellular and were comprised of single and tightly packed clusters of oval to spindle-shaped cells aggregated around branched capillaries. basement membrane material was observed in 6 cases (67%). The nuclei were uniform and oval, with finely granular chromatin and inconspicuous nucleoli in all cases except one. No mitotic figures or areas of necrosis were identified. A correct diagnosis of HPC was made on one primary lesion and all recurrent or metastatic lesions. CONCLUSIONS: HPCs show a spindle cell pattern in cytologic preparations and must be distinguished from more common spindle cell lesions. The presence of branched capillaries and abundant basement membrane material supports a diagnosis of HPC. immunohistochemistry and electron microscopy performed on FNA samples may be helpful in the differential diagnosis. FNA is a useful and accurate tool with which to confirm recurrent or metastatic HPC; however, prediction of the biologic behavior of HPC based on cytologic features is not feasible. Cancer (Cancer Cytopathol) copyright 1999 american cancer society.- - - - - - - - - - ranking = 4keywords = hemangiopericytoma (Clic here for more details about this article) |
3/38. color and duplex Doppler sonography of hemangiopericytoma.We report the color Doppler sonographic features in a case of hemangiopericytoma of the thigh in a 52-year-old woman. color Doppler sonography demonstrated the vascularity of the tumor, and spectral analysis showed waveform changes that suggested the presence of intratumoral arteriovenous shunting. The color Doppler findings correlated well with angiographic findings. color Doppler sonography can demonstrate intratumoral arteriovenous shunting in hemangiopericytoma and may be used to help avoid profuse bleeding when performing a preoperative biopsy.- - - - - - - - - - ranking = 6keywords = hemangiopericytoma (Clic here for more details about this article) |
4/38. Glomangiopericytoma causing oncogenic osteomalacia. A case report with immunohistochemical analysis.A 47-year-old woman suffered from gait disturbance due to back pain and muscle weakness. Laboratory data showed serum hypophosphatemia, elevated alkaline phosphatase, and a normal level of ionized calcium. Radiological examinations revealed multiple pathologic fractures in the ribs and pubic rami. She had had no episode of familial or any other notable disorder, and so she was initially treated with medication for adult-onset osteomalacia. However, 19 years later (when she was 66 years old), she noticed a soft-tissue tumor in her buttock. The tumor was excised. The histological features were those of glomangiopericytoma characterized by both glomus tumor-like and hemangiopericytoma-like structures. After removal of the tumor, her symptoms disappeared immediately. Laboratory data normalized 8 months later. To our knowledge, this is the first report of oncogenic osteomalacia caused by glomangiopericytoma.- - - - - - - - - - ranking = 1keywords = hemangiopericytoma (Clic here for more details about this article) |
5/38. Fibrous spindle cell lipoma: report of a new variant.Spindle cell lipoma is a benign tumor characterized by mature fatty tissue alternating with short fascicles of small spindle cells in a stroma that varies from fibrous to myxoid. The variable proportion of these elements among different examples of the neoplasm confers to spindle cell lipoma a variable microscopic appearance that can make the diagnosis difficult. Furthermore, in some instances, spindle cell lipoma may resemble liposarcoma, hemangiopericytoma, neurilemmoma, and other neoplasms representing a histopathologic pitfall. We report on two cases of spindle cell lipoma with abundant fibrous stroma reminiscence of fibroma and fibrolipoma. The name fibrous spindle lipoma is proposed for this tumor.- - - - - - - - - - ranking = 1keywords = hemangiopericytoma (Clic here for more details about this article) |
6/38. PNET-like features of synovial sarcoma of the lung: a pitfall in the cytologic diagnosis of soft-tissue tumors.Fine-needle aspiration (FNA) cytology of soft-tissue tumors is evolving. As more experience is gained, we are becoming aware of potential pitfalls. We describe 2 cases of synovial sarcoma of the lung, primary and metastatic, in patients who had FNA biopsy performed on a lung mass. The cytologic smears showed extremely cellular groups of malignant small round cells, intersected by small blood vessels, with numerous loose single cells, in a background of macrophages and mature lymphocytes. The tumors displayed monomorphic cells forming rosettes and displaying occasional mitoses. A diagnosis of neuroendocrine tumor/primitive neuroepithelial tumor (PNET) was suspected. Furthermore, this suspicion was supported by immunohistochemical stains, which showed positivity for a neuroendocrine marker, Leu 7 (case 1), and for a neural marker, CD 99 (O 13 or HBA 71) (both cases); and negativity for cytokeratins (case 1). The resection specimen of case 1 had mostly tightly packed small round cells, with occasional rosettes, similar to the FNA biopsy, and focal areas composed of spindle cells, organized in a focal fibrosarcoma-like and hemangiopericytoma-like pattern. A balanced translocation between chromosomes X and 18, demonstrated by both karyotyping and fluorescent in situ hybridization (FISH), enabled us to make a diagnosis of synovial sarcoma, which was histologically classified as poorly differentiated. Case 2 was a metastatic biphasic synovial sarcoma of the arm, with a prominent epithelial component. Synovial sarcoma, when composed mainly of small round cells on cytologic smears, is a great mimicker of neuroendocrine/PNET tumors, with light microscopic and immunohistochemical overlap. awareness of this potential pitfall may aid in preventing a misdiagnosis. Its recognition is of major concern, especially for the poorly differentiated variant, because it is associated with a worse prognosis.- - - - - - - - - - ranking = 1keywords = hemangiopericytoma (Clic here for more details about this article) |
7/38. Ten-year-old boy with hemangiopericytoma and human immunodeficiency virus infection.This report documents the first case of hemangiopericytoma in an hiv-infected child who is most likely a case of vertical transmission of hiv with slow progression to AIDS. We also raise the possibility that there is a causal relationship between hiv and hemangiopericytoma.- - - - - - - - - - ranking = 6keywords = hemangiopericytoma (Clic here for more details about this article) |
8/38. Regression of congenital fibrosarcoma to hemangiomatous remnant with histological and genetic findings.We report a rare case of congenital fibrosarcoma (CFS) showing regression during the course of disease, in which the histological and genetic alterations were investigated. This CFS, located on the patient's right hand, was a hemangiopericytomatous hypervascular tumor showing frequent mitosis and necrosis. Small lymphocytes, predominantly cytotoxic T cells and natural killer cells, infiltrated the tumor. At the age of 3 months, the patient received a partial resection of the tumor. At the age of 1 year, the hemangiopericytomatous tumor with a dilated vascular lumen remained, although most of the tumor cells exhibited focal necrosis with calcification and no mitotic activity. lymphocytes increased in number and intermingled with the tumor cells. At the age of 4 years, vascular tissue consisting of inner endothelial cells and surrounding pericytomatous actin-positive cells remained at the previous tumor locus. With reverse transcription-polymerase chain reaction analysis, ETV6-NTRK3 fusion transcripts were detected in tumor samples at 3 months and at 1 year, but not from those at 4 years of age. These genetic and histological changes suggest that the CFS either completely disappeared by apoptosis or showed mature transformation to hemangiomatous tissue with aging.- - - - - - - - - - ranking = 2keywords = hemangiopericytoma (Clic here for more details about this article) |
9/38. Myopericytoma of the thoracic spine: a case report.STUDY DESIGN: A case of myopericytoma of the thoracic spine is reported. OBJECTIVE: To report a recently described and extremely rare soft tissue neoplasm in the previously unreported location of the thoracic spine. SUMMARY OF BACKGROUND DATA: Myopericytoma is a recently described soft tissue neoplasm with perivascular myoid differentiation. All cases have been reported in the subcutaneous and superficial soft tissues of the extremities. This represents the first reported case of this unusual lesion in the spine. methods: A patient with a 3-month history of progressive weakness of the arms and legs was found to have a lytic lesion of T3. The lesion was surgically treated by curettage followed by a course of radiation. Presenting symptoms, imaging studies, histologic findings, and related literature are reviewed in this study. RESULTS: Histologic evaluation of sections of the surgically removed lesion revealed a concentric, periluminal proliferation of cells with prominent positive smooth muscle actin immunoreactivity. These findings are consistent with the diagnosis of a myopericytoma, a lesion not previously reported in the spine. CONCLUSIONS: This study shows the presence of a lesion in the thoracic spine only previously described in the soft tissue of the extremities. The diagnosis of myopericytoma should be included, along with hemangiopericytoma, in the differential diagnosis of lytic lesions of the spine.- - - - - - - - - - ranking = 1keywords = hemangiopericytoma (Clic here for more details about this article) |
10/38. Fine-needle aspiration smears from lipomatous hemangiopericytoma need not be confused with myxoid liposarcoma.Lipomatous hemangiopericytoma (LHPC) is a rare benign soft tissue tumor that may mimic soft tissue sarcoma clinically. Despite the fact that LHPC shares most of the histologic features with solitary fibrous tumor, it may be occasionally misdiagnosed as myxoid liposarcoma or some other type of spindle-cell sarcoma. While some studies have addressed the histological features and origin of LHPC, no reports of cytological findings have been published. The author describes the cytological features of LHPC in two patients with correlations to histological and clinical findings. One of aspirates was misdiagnosed as being myxoid liposarcoma, while the other one was correctly diagnosed by a combination of FNAB and core needle biopsy (CNB). Cytological evaluation of LHPC can be problematic due to its rarity and to its similarity with other spindle-cell or fatty tumors. Correct diagnosis requires an awareness of cytologic features of this rare tumor and the use of ancillary studies.- - - - - - - - - - ranking = 5keywords = hemangiopericytoma (Clic here for more details about this article) |
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