The clinical and radiologic manifestations of hemangiopericytoma

The clinical and radiologic findings in nine patients with hemangiopericytoma were reviewed. There were eight women and one man with a mean age of 46 years. Seven of the neoplasms, including two locally recurrent tumors, were in the pelvis and two were in the thigh. Conventional radiographs were available for all patients. Five patients were evaluated by sonography, four by CT, three by angiography, and two by MR imaging. There was evidence of compression of adjacent viscera by six of the seven pelvic tumors with associated hydronephrosis in one patient. One thigh lesion had focal areas of speckled calcification. All five neoplasms evaluated by sonography showed a well-circumscribed hypoechoic lesion and three had significant sound through-transmission. Hypervascularity was documented by contrast-enhanced CT or angiography in each of three patients in whom these procedures were performed. Surgical resection of the pelvic neoplasms was complicated by marked hemorrhage. Hemangiopericytoma should be considered in the differential diagnosis of well-circumscribed hypervascular tumors in a middle-aged patient.     

Radiation-induced sarcoma of bone: CT findings in 19 cases

We reviewed the CT findings in 19 cases of radiation-induced sarcoma of bone. The latent period before development of the sarcoma ranged from 5 to 50 years (mean, 17 years). In all 19 lesions, a soft-tissue extraosseous component was seen on CT, and 18 of them had associated bone destruction. Expansion of the affected bone and tumor-matrix mineralization each were present in 10 patients, but occurred together in only five patients. Periosteal reaction was seen in five patients, one of whom had an associated fracture. Radiation osteitis could not be identified on CT scans in the affected bone of any of the patients when tumor was present, but it was present in contiguous bone in two patients and had been shown 6 years before tumor became apparent in the affected bone in one other patient. Radiation-induced sarcoma of bone should be considered when bone destruction and an associated soft-tissue mass are shown on CT, or when changes occur in the appearance of previously stable irradiated bone.     

Alveolar soft-part sarcoma of the head and neck: clinical and imaging features in five cases

BACKGROUND AND PURPOSE: Alveolar soft-part sarcoma (ASPS) of the head and neck is an extremely rare malignancy. Although the clinical and imaging features of this tumor have been reported, a periodic review of unusual tumors is useful. The purpose of this study was to describe the clinical and imaging features of ASPS of the head and neck. METHODS: Between January 1990 and May 2004 at our institution, five head and neck ASPS were diagnosed in five patients (two male and three female patients; age range, 4-22 years). Clinical and imaging findings were reviewed retrospectively. Imaging studies consisted of contrast material-enhanced CT (in four patients), MR imaging (in four patients), and digital subtraction angiography (in two patients). RESULTS: The locations of the tumor were tongue in two cases, larynx in one case, buccal space in one case, and paravertebral space in one case. This tumor appeared as a large lobulating-contoured mass with high signal intensity and flow voids on T2-weighted images and showed strong enhancement on contrast-enhanced CT and MR images. Preoperative angiography showed high vascularity. Wide surgical excisions were performed in four cases. Mean follow-up periods were 16 months (range, 6-30 months), and no recurrence was noted except for the laryngeal case. CONCLUSION: ASPS should be included in the differential diagnosis of head and neck tumor when a slow-growing, large mass with high signal intensity and flow voids on T2-weighted images and strong enhancement on contrast-enhanced CT or MR image is seen, particularly in young female patients.     

Pulmonary Metastases of Alveolar Soft-Part Sarcoma: CT Findings in Three Patients

Alveolar soft-part sarcoma is a rare soft tissue sarcoma of young adults with unknown histogenesis, and the organ most frequently involved in metastasis is the lung. We report the CT findings of three patients of pulmonary metastases of alveolar soft-part sarcoma, which manifested as clearly enhanced pulmonary nodules or masses. On enhanced scans, some of the masses were seen to contain dilated and tortuous intratumoral vessels.     

Angiographic features of alveolar soft-part sarcoma]

The angiographic findings were analyzed in five patients with alveolar soft-part sarcoma. The angiographic appearance of the tumors was the same in all five cases: hypervascularity of the tumor including encasement, dilatation, tortuosity and displacement of feeding arteries, remarkable tumor stain and early venous filling. These angiographic findings are considered to be characteristic of alveolar soft-part sarcoma in the differential diagnosis of hypervascular soft tissue mass.     

MRI of alveolar soft-part sarcoma

Alveolar soft-part sarcoma (ASPS) is rare. We present a case of a 30-year-old woman with a 6-month history of a palpable mass in her left thigh. MRI showed an 8-cm mass and a satellite nodule at the left gluteus muscle. The main tumor exhibited an isointense signal on T1-weighted images and high-signal-intensity areas with low-signal-intensity scanty solid components on T2-weighted images. MR angiography showed dilated and tortuous veins around the tumor. Histologic findings were compatible with ASPS.     

Arterial embolization therapy for metastatic bone and soft-tissue tumors with microcatheter and microcoils

Transcatheter arterial embolization therapy was performed in fifteen patients with hypervascular metastatic bone and soft-tissue tumors (7 from renal carcinoma, 5 from hepatocellular carcinoma, and one each from breast, thyroid, and cholangiocarcinoma). Sites of metastasis were spine (7), pelvis (5), skull (2), paraspine (2), chest wall (1), and thigh (1). Five patients had not responded to previous radiation therapy and hyperthermia. Embolization of feeding arteries was performed superselectively with long tapered catheters or coaxial microcatheters. Emulsion of Lipiodol and anticancer agent, polyvinyl alcohol sponge, gelatin sponge, and microcoils were used as embolic materials in various combinations. Relief of pain was experienced in 14 of 15 patients. Two patients were operated following embolization with minimal blood loss. Change in tumor size was evaluated by CT or MRI in ten patients. Reduction of tumor size were more than 50% in five patients, from 25% to 50% in two, and no change in three patients. Especially, patients embolized with microcatheter and microcoils showed excellent long-term results. No serious complications were seen. In conclusion, superselective arterial embolization therapy with coaxial microcatheter and microcoils was proved to be an useful treatment for hypervascular metastatic bone and soft-tissue tumors.     

Imaging findings of vascular lesions in the head and neck

Vascular lesions of the head and neck include vascular neoplasms, vascular malformations, and hypervascular lesions, derived from nonvascular soft-tissue elements. We retrospectively evaluated magnetic resonance imaging and computed tomography images of vascular lesions located in the head and neck. Twelve patients (seven males, five females) aged 1–68 years (mean age, 35.25 years) were included in this study. Most of the vascular lesions in our study were histologically diagnosed. The lesions were as follows: a hemangioma located in the parotid space (n=1); a hemangioendothelioma located in the parotid space (n=1); a hemangiopericytoma located in the larynx (n=1); a juvenile angiofibroma located in the nasopharynx (n=1); a glomus tumor located in the carotid bifurcation (n=1); venous malformations located in the parapharyngeal space, the pterygoid area, the orbital space, and the larynx (n=4); lymphatic malformations located in the parotid space and the supraclavicular area (n=2); and an arteriovenous malformation located in the infratemporal fossa (n=1). We present rare vascular lesions of the head and neck, which have typical radiological findings.The International Society for the Study of Vascular Anomalies (ISSVA) classification system provides an approach based on histopathology, clinical course, and treatment (1). The ISSVA classification system divides vascular anomalies into two primary biological categories: vascular neoplasms and vascular malformations. Vascular neoplasms include infantile hemangioma, congenital hemangioma, hemangioendothelioma, tufted angioma, angiosarcoma, and dermatologic acquired vascular neoplasms. Vascular malformations include low-flow malformations (capillary, venous, and lymphatic), high-flow malformations (arterial malformation, arteriovenous malformation, and arteriovenous fistula), and combined malformations (i.e., venolymphatic malformation). Vascular neoplasms have increased endothelial cell turnover (i.e., they proliferate and undergo mitosis), whereas vascular malformations are structural abnormalities of the capillary, venous, lymphatic, and arterial system that grow in proportion to the child (1). There are also lesions, which demonstrate marked neovascularity despite being derived from nonvascular soft-tissue elements. These hypervascular lesions should be distinguished from the vascular endothelial cell-derived neoplasms existing in the ISSVA classification system.We retrospectively evaluated magnetic resonance imaging (MRI) and computed tomography (CT) images of vascular lesions located in the head and neck, between 2005 and 2008 in our institution. Twelve patients (seven males, five females) aged 1–68 years (mean age, 35.25 years) were included in this study. Informed consent was obtained from all patients. We identified two vascular neoplasms existing in the ISSVA classification sytem: a congenital hemangioma and a hemangioendothelioma. In addition, we identified a hemangiopericytoma, a juvenile angiofibroma, and a glomus tumor, which are hypervascular lesions derived from nonvascular soft-tissue elements. There are four venous malformations, two lymphatic malformations, and an arteriovenous malformation in our study. Most of these vascular lesions were histologically diagnosed. Examinations were performed by a 16-slice CT and a 1.5 Tesla magnetic resonance scanner.     

Synovial sarcoma in childhood

The clinical and radiologic findings in seven children with synovial sarcoma are described. The five boys and two girls had a mean age at presentation of 4.4 years. All seven had the lesion situated in an extremity. Plain radiographs in four revealed the presence of a soft-tissue mass with no calcification or bone and joint involvement. In two patients studied with computed tomography (CT), the primary lesions had peripheral irregular areas of enhancement with central areas of poor enhancement, reflecting the necrotic, cystic, and hemorrhagic changes found in the centers of these tumors. Although the exact margins of these lesions were difficult to define accurately even with intravenous contrast enhancement, CT is still recommended as the best imaging method for assessing the local extent of the primary tumor and is a useful tool in the planning of appropriate therapy as well as the gauging of tumor response to ongoing treatment.     

Alveolar soft-part sarcoma of the tongue

Alveolar soft-part sarcoma is a rare, aggressive malignancy of uncertain histologic origin with a propensity for vascular invasion and distant metastasis. This neoplasm may mimic benign vascular neoplasms or malformations but careful evaluation of the unique imaging features on CT scans, MR images, and angiograms lead to the correct diagnosis. We present a case of alveolar soft-part sarcoma of the tongue and emphasize its radiologic and clinical features.     

Elastofibroma: MR and CT appearance with radiologic-pathologic correlation.

OBJECTIVE. The purpose of our study was to determine the MR and CT appearances of elastofibroma and correlate the imaging features with the underlying pathologic findings. MATERIALS AND METHODS. We reviewed retrospectively the MR and CT findings in five cases of elastofibroma. All patients had a soft-tissue mass; one patient also complained of pain. The mean age of the patients was 71 years (range, 63-79 years). Four lesions occurred in the subscapular region, and one occurred in the thigh. In addition, we reviewed and compared the demographic data of 72 histologically proved cases for which we had archival data. RESULTS. Three of four lesions evaluated with spin-echo MR imaging were approximately isointense with skeletal muscle and contained areas with a signal intensity similar to that of fat; these corresponded to areas of dense collagen and interspersed fat, respectively. In the fourth case, the MR appearance was nonspecific. In one case, MR imaging with gadopentetate dimeglumine showed areas with and without enhancement. Three of four lesions evaluated with CT had variable margins, with tissue attenuation similar to that of the adjacent soft tissue as well as scattered areas of decreased attenuation, suggesting fat within the lesion. In one case, the lesion was well defined and relatively homogeneous with an attenuation less than that of skeletal muscle. CONCLUSION. The MR and CT features of elastofibroma are different from those of most other soft-tissue tumors, reflecting entrapped fat within a predominantly fibrous mass. Although these features are not pathognomonic, their presence in a subscapular lesion in an older patient suggests a presumptive diagnosis of elastofibroma.     

Granulocytic sarcoma of bowel: CT findings

PURPOSE: To evaluate retrospectively the computed tomographic (CT) findings of granulocytic sarcoma of the bowel. MATERIALS AND METHODS: The institutional review boards of all participating institutions approved this study and waived the requirement for informed consent. CT scans were retrospectively reviewed in eight patients (seven men, one woman; age range, 23-71 years; mean age, 46 years) with pathologically proved granulocytic sarcoma of the small and/or large bowel. CT findings were evaluated with regard to the sites, morphologic characteristics, and contrast material enhancement patterns of the lesions, along with other ancillary findings (ie, peritoneal and mesenteric infiltration, ascites, lymphadenopathy, bowel perforation, and obstruction). RESULTS: Eight patients had a total of 13 lesions in the bowel (of which eight were pathologically proved), involving the duodenum (n=1), jejunum (n=2), ileum (n=5), sigmoid colon (n=1), and rectum (n=4); multifocal bowel lesions were noted in four patients. The lesion varied in shape, with wall thickening alone in three of 13 lesions, an intraluminal polypoid mass in four, an exophytic mass in one, and a combination of findings in five. Contrast material enhancement, relative to the back musculature, showed isoattenuation in seven lesions, hyperattenuation in four, and hypoattenuation in two. Five of eight patients had multiple peritoneal masses with diffuse mesenteric or peritoneal infiltration. Ascites was present in six of eight patients; lymphadenopathy (especially in the mesentery), in five; bowel perforation, in two; and bowel obstruction, in one. CONCLUSION: Granulocytic sarcoma of the bowel is characterized by variability in shape and contrast enhancement and has a high predilection for mesenteric and peritoneal spread.     

Combined functional and morphological imaging consisting of gated myocardial perfusion SPECT and 16-detector multislice spiral CT angiography in the noninvasive evaluation of coronary artery disease: first experiences

INTRODUCTION: Appropriate diagnosis and therapy of coronary artery disease (CAD) frequently require information about both the functional and morphological status of the coronary artery tree. We hypothesized that the combination of multislice spiral CT (MDCT) angiography and myocardial perfusion SPECT (MPI) provides accurate allocation of perfusion defects (PD) to their determining coronary lesion. METHODS: Twenty patients (14 male, mean age 64+/-9.2 years) with known CAD were retrospectively studied. Gated MPI, CT angiography using a 16-detector CT scanner, and conventional coronary angiography (CCA) were performed in each patient. Reversible and fixed PD were subsequently allocated to their determining lesion separately by different observers for MDCT angiography and CCA. RESULTS: All patients showed significant CAD in CCA; six patients with one-, six with two-, six with three-, and two with four-vessel disease; three patients had bypass grafts; and five patients had prior myocardial infarction. Correct diagnosis of CAD was stated in 14 of 20 patients by MDCT angiography. Five reversible and five fixed PD were detected in 9 of 20 patients; one patient showed both reversible and fixed PD. Five of five reversible PD could be allocated to appropriate coronary artery stenoses in CCA. In MDCT angiography, five of five reversible PD were allocated to the same lesions; all lesions were rated as >/=50%. CONCLUSIONS: The preliminary results of the present study show high accuracy for multislice spiral CT angiography to allocate reversible perfusion defects in myocardial scintigraphy to their determining coronary artery lesions in a small patient collective with known coronary artery disease.     

Use of MR imaging to assess results of chemotherapy for Ewing sarcoma

MR imaging was used to monitor the results of initial chemotherapy of primary Ewing sarcoma of bone. The signal intensities of the soft-tissue and marrow components of the tumor were evaluated on T2-weighted images obtained in 10 patients (nine with responsive tumors) at presentation and during and immediately after completion of two cycles of chemotherapy. MR evidence of marrow and soft-tissue involvement was seen in all tumors at presentation. After treatment, the bone-marrow component of the nine drug-sensitive tumors showed an increase in signal intensity that in eight cases became comparable to that of water. Changes in signal intensity of the soft-tissue component were variable, consisting of increases in two of the responsive lesions, no change in three, a decrease in two, and complete resolution of the soft-tissue mass in two. There was no increase in signal intensity of either the bone-marrow or the soft-tissue component of the single nonresponsive tumor. All of the responsive tumors showed advanced healing, and abundant bony sclerosis was apparent on CT. Bone-marrow examinations, performed in seven of the nine patients with responsive lesions, disclosed no evidence of tumor in four. Two patients had residual extramedullary tumor; the nonresponsive lesion contained sheets of tumor cells. The increase in marrow signal intensity on T2-weighted images was associated with replacement of marrow elements by a loose, hypocellular myxoid matrix containing modest amounts of collagen, consistent with response to chemotherapy and eradication of disease. Therefore, an increase in the T2-weighted signal intensity of the bone-marrow component of Ewing sarcoma of bone reflected a favorable response to chemotherapy. MR signal changes, however, were not predictive of resolution of malignant disease within adjacent soft tissue.     

Synovial sarcomas of the head and neck: CT and MR imaging findings of eight patients

BACKGROUND AND PURPOSE: Synovial sarcomas are soft-tissue tumors that rarely occur in the head and neck. The purpose of this study was to evaluate their CT and MR imaging appearance and to show that they may have a surprisingly benign imaging appearance. METHODS: Eight patients with histologically proved synovial sarcoma underwent CT; additionally, MR imaging examinations were performed in five of the eight cases. Attenuation and signal intensity on CT scans and MR images, respectively, were studied by two radiologists. They analyzed the location, size, margins, homogeneity, presence of adenopathies and infiltrative signs, and enhancement after injection of contrast medium. RESULTS: Four tumors were located in the hypopharynx, two arose from the infratemporal fossa, one arose from the maxillary sinus, and one arose from the faucial tonsil. Tumor sizes ranged from 27 to 70 mm. On CT scans and MR images, six lesions were homogeneous and well defined, with smooth margins. The remaining tumors were heterogeneous. In two cases, adjacent tissues were invaded. Calcifications were observed in one case and adenopathy in two cases. In three cases, the lesions were isointense on T1-weighted MR images and hypointense on T2-weighted MR images, and in the other two cases in which MR imaging was performed, the lesions were both isointense and hypointense on both T1- and T2-weighted images. Only the two local recurrent lesions were multilocular. CONCLUSION: Synovial sarcomas are aggressive sarcomas that may appear "benign" in some cases. In a young man, a synovial sarcoma may be suspected when a well-demarcated, homogeneous lesion is found in the head and neck.     

CT检查中窗技术的合理应用对提高肝内病灶检出率的意义

目的评价在传统软组织窗基础上加用肝组织窗对提高肝内病灶检出率的意义。方法接受腹部CT增强扫描的859例患者的895张顺序编号的CT片是由两位有经验的放射学医师评价的。所有的肝脏成像均采用两种窗技术进行，即起初软组织窗和随后肝组织窗。逐例记录了两种技术检出的病灶数与符合率。确定了利用肝组织窗有新增病灶的患者比例。对两种窗技术在检出病灶数方面的差异进行了统计学分析。结果在859例中，205例（24％）患者在软组织窗和肝组织窗上有肝脏病灶，其中，40例（14．6％）患者随着肝组织窗的加用，检出的病灶数亦增多。这40例中的14例患者具有在软组织窗上看不见的新增病灶。两种窗技术的病灶检出率有统计学差异（P〈0．05）。结论 单一的软组织窗不足以全部发现肝内病灶，因此，有些病灶容易漏诊，而肝组织窗的加用，可有效提高肝脏病灶的检出率与诊断准确性。     

腺泡状软组织肉瘤的MRI表现

目的：探讨腺泡状软组织肉瘤的MRI表现。方法：9例手术病理证实的腺泡状软组织肉瘤,术前均进行MRI平扫,其中4例行增强扫描,2例行1H-MRS扫描。对肿瘤的发生部位、大小、肿瘤形态、肿瘤的强化和1H-MRS表现进行分析评价。结果：位于大腿4例,小腿2例,上臂2例,臀肌和髂腰肌1例,8例肿瘤位于深部肌群;肿瘤体积平均大小5.1 cm×7.8 cm;5例呈分叶状;3例肿瘤周围有软组织结节;7例肿瘤的信号均匀,呈中等T1长T2信号,2例有囊变坏死;4例增强扫描者,瘤实质明显强化;2例1H-MRS均表现为3.2 ppm出现明显的Cho峰。结论：腺泡状软组织肉瘤的MRI表现缺乏特异性,但在一定程度上能够反应肿瘤的恶性特点,对于术前肿瘤定性诊断和指导临床治疗具有一定价值。     

Tomographic renal cortical scintigraphy: correlation with intravenous urography, computed tomography, ultrasonography, angiography, and nuclear magnetic resonance imaging

This study evaluates single-photon renal tomoscintigraphy (SPECT) in the evaluation of renal masses and correlates this modality, where indicated, with computed tomography (CT), ultrasonography (US), angiography (ANGIO) and nuclear magnetic resonance imaging (NMR). Eight patients with renal cortical lesions detected on intravenous urography (IVP) were evaluated by SPECT and planar nuclear imaging using Tc-99m glucoheptonate (GH). Three of these patients were felt particularly likely to have renal tumors and were additionally evaluated with US, CT, ANGIO and NMR. The five patients with nodules on IVP that were not particularly suggestive of malignancy had functioning, benign, renal tissue accounting for their IVP lesions. Four of five were found by planar-GH nuclear imaging, five/five by SPECT-GH. In addition, SPECT-GH allowed better "confidence" in the normal renal tissue diagnosis in three/five cases. Of the three renal lesions that were highly suggestive of malignancy, two were hypernephromas and one was hypertrophied functioning cortical tissue. All three were correctly identified prospectively on SPECT-GH; however, one hypernephroma was missed on planar-GH. NMR, CT, and ANGIO detected only one of two hypernephromas prospectively (US detected both); all four modalities incorrectly diagnosed the hypertrophied tissue suggestive of malignancy.     

Langerhans' cell histiocytosis of the temporal bone in pediatric patients: imaging and follow-up

OBJECTIVE: The purpose of this study was to review the initial clinical and radiologic manifestations and the follow-up of pediatric patients with Langerhans' cell histiocytosis affecting the temporal bone. MATERIALS AND METHODS: We retrospectively studied 14 patients with Langerhans' cell histiocytosis affecting the temporal bone. All patients were examined initially and sequentially with CT. In six patients, MR imaging was also done. RESULTS: Temporal bone involvement was the initial form of presentation in 12 patients. In eight patients, temporal bone involvement presented as an isolated manifestation, and in four it was associated with multisystemic involvement. In the remaining two patients, temporal bone involvement appeared during the course of the Langerhans' cell histiocytosis. Bilateral involvement was seen in four patients. In two patients, the temporal bone was affected only at the petrous apex. CT showed destruction of bone in all 14 patients and an associated soft-tissue homogeneous mass after injection of i.v. contrast material in 12 patients. CT showed a heterogeneous appearance of the soft-tissue mass in two patients. The average period of follow-up was 5 years. In seven of the 14 patients, the disease had a satisfactory evolution in which the bony lesions of the temporal bone reossified and remodeled over the course of a year. CONCLUSION: In Langerhans' cell histiocytosis, involvement of the temporal bone is usually seen on radiographs as extensive lytic lesions associated with soft-tissue masses. The lesions that remit show early disappearance of the soft-tissue mass, followed by reossification and remodeling of the involved bone. Patients with limited initial involvement of the temporal bone have a better prognosis on long-term follow-up than do patients with the multisystemic form.     

Multiple imaging modalities in a case of hibernoma

Hibernoma is a rare hypervascular benign tumour that originate from brown fat. A case of hibernoma of the thigh, examined by xeroradiography, ultrasound, CT and angiography, is reported. The characteristics of this tumour are considered.