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Gastrointestinal Imaging |
1 From the Department of Radiology, Duke University Medical Center, Erwin Rd, Box 3808, Durham, NC 27710 (W.M.T.); Departments of Radiologic Pathology (A.D.L.) and Hematopathology (N.S.A.), Armed Forces Institute of Pathology, Washington, DC; Department of Radiology and Nuclear Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md (A.D.L., R.M.A); Department of Radiology, La Paz University Hospital, Madrid, Spain (L.G.); and Department of Radiology, University of Maryland Medical Center, Baltimore, Md (R.M.A.). From the 2003 RSNA Annual Meeting. Received February 18, 2004; revision requested April 26; revision received May 25; accepted June 28. Address correspondence to W.M.T. (e-mail: thomp132@mc.duke.edu).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
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MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required. Records of 12 cases of proved angiosarcoma of the spleen were accessed from the files of the Armed Forces Institute of Pathology. Clinical, pathologic, and imaging findings were reviewed. Presenting signs and symptoms were recorded, and the pathologist confirmed the diagnosis and determined gross and microscopic morphologic findings in each spleen. Radiologists reviewed available images to determine the size of the spleen and mass, amount of splenic involvement by the tumor (if enhanced at computed tomography [CT] and magnetic resonance [MR] imaging), and amount of nonviable tumor determined as decreased echogenicity at ultrasonography (US) and lack of enhancement at CT and MR imaging. Imaging and pathologic findings were compared. Five US, 10 CT, three MR, and two angiographic images were reviewed by two experienced abdominal radiologists.
RESULTS: There were seven men and five women (age range, 36–86 years; mean, 55 years). The most common symptom was upper abdominal pain in eight (67%) patients: Pain was acute for 24 hours prior to admission in one patient and chronic (range, 1–6 months) in seven patients. At imaging, the spleen was enlarged (>12 cm in length) in nine patients. The most common finding, seen in seven (58%) patients, was a complex mass or masses in an enlarged spleen. Four of these patients had evidence of metastases and one had intraperitoneal hemorrhage. Two patients had solitary hypervascular tumors and liver metastases. One patient had a normal-sized spleen with multiple lesions that ranged 2–3 cm in size, as well as metastases to the spine. The 11th patient had two small lesions, with small calcifications in the periphery of one lesion. The 12th patient had intraabdominal hemorrhage around the spleen and no obvious mass at CT. Tumor necrosis was confirmed at histologic evaluation in nine patients.
CONCLUSION: The most common clinical finding was upper abdominal pain. Angiosarcoma of the spleen could be suggested in the majority of cases (83%) by using the imaging features of splenic mass with evidence of metastatic disease.
© RSNA, 2005
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
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In most reported cases, ultrasonographic (US) images show splenomegaly with heterogeneous masses that are echogenic and have increased vascularity at Doppler evaluation (3,6,7). Computed tomographic (CT) scans have been reported to show splenomegaly, evidence of recent or remote hemorrhage within the tumor, and tumoral enhancement (3,4,7,9,11,13). Calcification has been reported in some cases (10). The reported magnetic resonance (MR) imaging features include masses of low signal intensity on T1-weighted images, heterogeneously high signal intensity on T2-weighted images, and hyperintense contrast enhancement following intravenous administration of gadopentetate dimeglumine. The purpose of our study was to retrospectively evaluate the clinical, pathologic, and imaging features of primary splenic angiosarcoma in a series of 12 patients and to compare our findings with those in the current literature. To our knowledge, our access to information for 12 patients would allow us to report results for the largest imaging series to date.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
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Clinical Data and Histopathologic Review
Clinical data were available in all cases and were reviewed by two experienced abdominal radiologists (W.M.T., 30 years in practice, and A.D.L., 10 years in practice) for patient age, sex, and presenting signs and symptoms. All patients underwent splenectomy. Histopathology records were available for all patients, and an experienced hematopathologist (N.S.A., 17 years in practice) reviewed all the pathologic material. The hematoxylin-eosin–stained slide material was reviewed by the hematopathologist in 11 cases to confirm the morphologic diagnosis of angiosarcoma. The slide material for the 12th case could not be located, but records indicated that a pathologist at the Armed Forces Institute of Pathology had previously confirmed the diagnosis of angiosarcoma. After reviewing the histopathologic findings, the hematopathologist reviewed the gross pathologic findings.
Photographs of gross pathologic specimens were available for 10 patients. The pathology records for each patient were reviewed to establish the splenic size and the size of each tumor, as well as to determine the presence or absence of hemorrhage, fibrosis, and necrosis on gross pathologic slices of the tumor.
Imaging Review
Two abdominal radiologists (A.D.L. and W.M.T.) retrospectively reviewed all the images before reviewing the imaging reports for the 12 patients. Only the histopathologic diagnosis in each patient was known at the time of the image interpretation. Final diagnosis was made by consensus. The interpreting radiologists did not know the clinical data and gross pathologic results at the time of initial interpretation. All of the images had been digitized and were reviewed by using a computer workstation. The images were available with soft-tissue window settings. CT workstation functionality to adjust window and level settings was available in only one of the 12 cases. All criteria for each study were reviewed by both authors at the same time, and a consensus was reached for each finding.
There were five US images, 10 CT scans, three MR images, and two angiograms available for review. For five patients, both CT and US images were available for review. For one patient, US, CT, and MR images were available. The patient records included reports from all the imaging studies. There were reports from two US studies and one CT study for which there were no images, so these three studies were not included in the image evaluation. Because our patients are referred from many different institutions, the images were obtained by using a variety of equipment models and protocols. Therefore, the acquisition techniques and injection protocols were not standardized. In addition, in some cases, only a limited number of images from the US and MR examinations were available for review.
The splenic size was determined on the basis of the length of the spleen, as determined from the images, when possible, and subsequently from the reports from the institutions submitting the cases. A spleen with a craniocaudal dimension greater than 12 cm was considered enlarged (14–16).
All images were evaluated for evidence of metastases. Lymph nodes larger than 1 cm in the mesentery and retroperitoneum were considered to indicate positive findings. The liver, lower thoracic spine, and lumbosacral spine were evaluated, but we could not evaluate the lungs because images with the appropriate window setting were not available for review.
US images.—The five US images were reviewed to determine the size of the spleen; presence of a focal mass or diffuse masses; mass echogenicity (hyper- or hypoechoic relative to the adjacent normal splenic parenchyma) and homogeneity (homogeneous or heterogeneous); whether there were hypoechoic regions within the spleen that suggested necrosis; and vascularity, as assessed at spectral Doppler evaluation (increased or decreased vascularity relative to the adjacent normal splenic parenchyma). A spleen that was longer than 12 cm was considered enlarged (14).
CT scans.—The CT techniques were not standardized because the studies were performed at 10 different institutions over a 19-year period. Eight of the CT studies were performed after 1999. All 10 CT studies were performed after administration of intravenous contrast material, and in four of the patients, both pre- and postcontrast studies were performed. With hepatic enhancement patterns used as a guide, it was determined that seven of 10 studies were performed during the early portal venous phase and three were performed during the late portal venous phase only. The early portal venous phase was defined on the images as enhancement of the portal veins that was greater than that of the adjacent nonenhancing liver parenchyma. The late portal venous phase was defined on the images as mild enhancement of the liver with respect to the portal veins (17,18). There were five CT scans (50%) that included the entire spleen, but CT reports were available for all cases, so splenic length could be determined in each of the 10 cases.
The name of the manufacturer of the equipment used was listed for only one of the US studies, and the probe frequency was listed for only two US studies. A state-of-the-art Siemens system with a 2–8-MHz probe was used in one case. A 4-MHz probe was used in another case. Three of the CT studies were performed by using 10-mm-thick contiguous sections, but no manufacturer name was listed on the CT scans obtained. Five CT studies were performed by using scanners made by GE Medical Systems (High-Speed Advantage scanner used in two cases, LightSpeed scanner used in three cases), and the section thicknesses used in these studies ranged from 2.5 to 10.0 mm. Two CT studies were performed by using Somatom Plus (Siemens) scanners; a section thickness of 8 mm was used in both of these studies. All 10 CT studies were performed only in the portal venous phase after intravenous administration of contrast material. All three MR studies were performed by using 1.5-T imagers from GE Medical Systems. In each patient, MR imaging was performed before and after contrast enhancement in the portal venous phase.
The 10 CT scans were reviewed to determine the splenic size and the presence or absence of a mass or of multiple masses. If present, the number of masses was determined along with size (visually assessed, smallest and largest number measured), shape (round, oval, or irregular), and margins (well defined or ill defined); attenuation and enhancement patterns (homogeneous or heterogeneous) were compared with those of the adjacent splenic parenchyma. The masses were also evaluated for the presence or absence of a capsule, calcification, or extensive infiltrative growth that replaced normal splenic parenchyma. The scans were evaluated for secondary findings such as intraperitoneal hemorrhage, liver metastases, adenopathy, and other possible metastatic lesions.
MR images.—All three MR studies were performed with T2- and T1-weighted imaging before and after intravenous administration of gadopentetate dimeglumine (Magnevist; Berlex, Wayne, NJ). In all three patients who underwent MR imaging, additional imaging sequences were performed, but images from these additional sequences were not analyzed because of the substantial differences in the techniques and the small number of cases.
The additional sequences included T2-weighted coronal single-shot fast spin-echo imaging, T1-weighted transverse gradient-echo in-phase and opposed-phase imaging, and T2-weighted transverse fast spin-echo imaging with fat saturation. The pulse sequences varied from study to study, and, thus, the results obtained from these studies were not included because they did not add to the findings seen on T2- and T1-weighted images obtained with and without gadolinium enhancement.
Three MR images were reviewed to determine the splenic size, presence of a mass or of masses, tumor vascularity determined on the basis of contrast enhancement, signal intensity characteristics of the tumor, and presence of areas with abnormal signal intensity suggesting tumor necrosis. The liver and upper abdomen were evaluated for metastases.
Angiograms.—The two angiograms were reviewed to determine the vascular appearance of the tumor—specifically, neovascularity and puddling of contrast material.
Data Comparison
After review of the images, comparison between the imaging findings and the clinical data, pathology reports, and photographs of the resected gross specimens (n = 10) was performed by the one of the two interpreting radiologists (W.M.T.). The appearance of the lesion on photographs of gross specimens (size, shape, margin, and capsule formation) was compared with the imaging appearance of the lesion. The photographs were also evaluated for evidence of hemorrhage or necrosis within the lesions.
The small number of cases did not allow for any statistical analysis to be performed.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
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All of the patients underwent splenectomy. In two cases, splenectomy was performed as a surgical emergency: One patient had life-threatening hemorrhage into the peritoneal cavity, and the other patient had substantial hemorrhage after a percutaneous CT-guided splenic biopsy was performed. In another patient, results of fine-needle aspiration biopsy of the spleen were positive for the diagnosis of angiosarcoma; biopsy was performed successfully without complications. Vertebral body metastases were found at CT-guided biopsy in two patients, and their spleens were then removed to resect the primary tumor. The rest of the patients underwent splenectomy because of imaging findings of a possible splenic malignancy.
Pathologic Findings
The diagnosis was confirmed in all 12 cases; diagnosis was confirmed in 11 cases by the hemopathologist at retrospective slide review and in one case by another pathologist (report review) at the Armed Forces Institute of Pathology. At gross examination, the mean splenic weight was 879 g (range, 120–3000 g). The normal weight of the spleen is 120–150 g, and only one patient in this series had a normal-sized spleen according to weight (1,2). Solitary masses were present in two patients, discrete multiple masses were present in three patients, and diffuse splenic infiltration with replacement of most of the spleen was present in six patients. In one patient who had splenic rupture at clinical presentation, no dominant mass was found; in this patient, hemorrhage and multiple nodules were found in an enlarged spleen.
Results of histologic evaluation confirmed areas of necrosis within the tumor in nine patients (Figs 1–3), hemorrhage in one patient, and no evidence of necrosis in two patients. In the latter two patients, areas of solid and cystic change without necrosis were reported.
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Imaging Findings
US images.—Findings at US are presented in Table 1. Four of the US studies were performed to evaluate abdominal pain, and the fifth was performed for localization during percutaneous aspiration. In two of the patients, there was Doppler information available.
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CT scans.—Findings at CT are presented in Table 2. The most common CT finding, found in six (60%) patients, was an enlarged spleen that contained a large heterogeneous complex mass or masses that almost completely replaced the spleen (Figs 2–4). In two of these patients, there was substantial contrast enhancement (Fig 3), and in the other four patients, there was only minimal contrast enhancement, with areas of decreased attenuation suggesting necrosis (Figs 2, 4). One of these patients had intraperitoneal hemorrhage from rupture of the lesion (Fig 4), and one patient had three tiny (<1 mm in size) calcifications in the periphery of the lesion.
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The 10th patient had diffuse enlargement of the spleen with a substantial amount of intraperitoneal fluid suggesting a ruptured spleen and a vague hypovascular mass with very poor margins present in the inferior aspect of the spleen.
Pre- and postcontrast CT scans were available for only four patients. On two precontrast CT scans, there was increased attenuation in the spleen owing to hemorrhage (Fig 4). CT scans in three patients showed relatively poor contrast enhancement (Fig 5), and the CT scan in the other patient showed no substantial contrast enhancement of the tumor.
Calcification was demonstrated in the tumor in one patient previously described (Fig 5), and, in one additional patient, calcifications were present as tiny (1–2 mm in size) areas of punctate density in the periphery of a very large lesion.
Areas of low attenuation on contrast material–enhanced CT scans, which indicated possible necrosis, were found in six (60%) of 10 patients (Figs 1–6). Evidence of intraperitoneal fluid indicating splenic rupture was found in two patients (Fig 4).
In six (60%) patients, there was CT evidence of liver metastases; in only one patient was presence of liver metastases definitely proved at biopsy (Figs 1, 3). These lesions were hypervascular in five patients (Figs 1, 3) and hypovascular in the other patient. Biopsy-proved metastases were found in the spines of two patients. Pathologically sized lymphadenopathy was present in one patient. The presence of metastatic disease within these lymph nodes was not confirmed at biopsy.
MR images.—Findings at MR imaging are presented in Table 3. Splenomegaly was present in all three patients who underwent MR imaging. In one patient, there was a solitary 6-cm mass that had a 1-cm-thick rim of decreased signal intensity and a central portion of high signal intensity on T1-weighted images (compared with the signal intensity of the adjacent splenic parenchyma) (Fig 7). On T2-weighted images, the rim and the center of the lesion showed higher signal intensity than that of the normal spleen (Fig 7). With the administration of gadopentetate dimeglumine, there was contrast enhancement in the rim of the lesion and no contrast enhancement in the center. Marked splenomegaly was present on images obtained in the other two patients, and the tumors virtually replaced the spleen (Fig 3). On T1-weighted images, there was mainly decreased signal intensity (compared with the signal intensity in normal spleen) with multiple small areas of increased signal intensity that ranged 1–4 cm in size (Fig 3). On T2-weighted images, these lesions showed high signal intensity with a few areas of decreased signal intensity. On images obtained after contrast agent administration, there was substantial contrast enhancement of viable tumor in all three patients (Fig 3). Only the rim of the lesion was enhanced in the one patient with a solitary lesion (Fig 7). Diffuse tumor nodules were seen to enhance in the other two patients (Fig 3).
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Angiograms.—Angiograms were obtained in only two of the 12 patients. In both patients, angiograms showed hypervascular masses with some neovascularity and puddling of contrast material.
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
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Splenic angiosarcoma has a very poor prognosis; the majority of the patients die within 12 months of diagnosis (1,2). Distant metastases occur most frequently in the liver (70% of cases), lung, pleural lymph nodes, bone, and brain (1,2). Similar to the results reported in the literature, the majority of our patients, eight (67%), had evidence of liver metastases at initial presentation.
Although ours is a small series, to our knowledge it represents the largest reported number of radiologic cases of splenic angiosarcoma. While there is fairly wide variation in the imaging findings reported in our series, the clinical findings in our patients are similar to those in previous clinical reports. The most common symptoms reported in the literature are abdominal pain (80%), fever (10%), malaise, and weight loss (1–3). Spontaneous splenic rupture is a frequent complication and is reported in the literature in up to 30% of patients (1–3). In most cases, as in our series, the spleen is enlarged and typically contains hemorrhagic nodules of varying size. Frequently, there is associated hemorrhage, infarction, and necrosis. In our study, there was imaging and pathologic evidence of hemorrhage and necrosis in the majority (83% [10 of 12]) of patients.
The reported US features of splenic angiosarcoma are splenomegaly and cystic and solid masses with mixed echogenicity (6,7,11). These are similar to the features seen on images in three of the five patients who underwent US in our series.
Similar to our results, previous CT reports have demonstrated solitary or multiple nodular masses of heterogeneous low attenuation in an enlarged spleen. Some of these masses show peripheral enhancement, and the margins of the lesions are often irregular or poorly marginated. On precontrast CT scans, the tumors may appear hyperattenuating, which corresponds to acute hemorrhage. On dynamic contrast-enhanced CT scans, the lesions may exhibit substantial peripheral contrast enhancement similar to that of hepatic hemangiomas (3,4,7,9,11,13).
The reported MR imaging features include nodular hypointense (relative to the normal adjacent splenic parenchyma) masses on both T1- and T2-weighted images; large masses with increased signal intensity on both T1- and T2-weighted images that are likely related to subacute hemorrhage, as well as tumor necrosis; and areas of decreased signal intensity within the tumor, owing to chronic hemorrhage with hemosiderin deposition. The patterns of contrast enhancement have been reported to be intense and multinodular with focal areas of nonenhancement related to tumoral hemorrhage and necrosis (8,9,11–13).
When findings from all imaging modalities were compiled, images in seven (58%) of the 12 patients showed splenomegaly and evidence of a large mass (or masses) in the spleen. A diagnosis of malignant tumor could be suggested in six of these patients, as there was evidence of liver metastases in four patients, metastases to the spine in one patient, and huge masses that replaced the spleen in one patient. In a seventh patient, there was evidence of hemorrhage into both the spleen and the peritoneal cavity. In both patients with solitary lesions, there was evidence that the lesions were hypervascular and that the patients also had liver metastases. In one of the two patients with multiple lesions (too numerous to count) in the spleen, there was evidence of metastases to the spine. Therefore, a diagnosis of a primary malignant splenic tumor, made on the basis of the imaging findings, could be suggested in 10 (83%) of the 12 patients. Angiosarcoma would have been included high on the list of differential diagnoses in these cases (Table 4).
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Splenic hemangioma is the most common type of benign primary neoplasm of the spleen (3,9,20,21). Splenic hemangiomas are typically hypoattenuating masses on CT scans that may show a contrast enhancement pattern similar to that of hepatic hemangiomas, with a pattern of mottled contrast enhancement on delayed-phase CT scans (3,9,13,20). On occasion, calcification, cyst formation, and fibrosis may be present within the hemangioma. Diffuse involvement of the spleen (hemangiomatosis) is rare (3,9,13,20). The MR imaging appearance of splenic hemangioma is similar to that of hemangioma of the liver. The lesion will be hypo- or isointense (compared to signal intensity of normal spleen) on T1-weighted MR images and hyperintense on T2-weighted MR images. T2-weighted images may show heterogeneous signal intensities, which represent mixed cystic and solid components of a hemangioma. T1-weighted images obtained after contrast administration may demonstrate a difference between the cystic and solid components. Subacute hemorrhage or proteinaceous fluid will have high signal intensity on T1-weighted MR images (3,13,21).
Littoral cell angiomas are splenic vascular tumors that could mimic the findings of relative hypovascular angiosarcomas (2,22,23). On CT scans, the most common finding reported is splenomegaly with innumerable splenic masses that range in size from 0.2 to 6 cm (22). In the published report of one case, CT scans demonstrated contrast enhancement with complete filling in of the masses, so that on the late portal venous phase scans, the masses were indistinguishable from the normal spleen (22). The signal intensity of the lesions on MR images is characteristic, showing markedly low signal intensity on both T1- and T2-weighted images. This classic appearance is due to the presence of hemosiderin because of the hematophagocytic capacity of the neoplastic cells (3,23).
Lymphangioma could mimic a relatively avascular splenic angiosarcoma of the spleen. On US images, lymphangiomas have been described as well-defined hypoechoic masses that may contain septations and intralocular echogenic debris. CT findings include sharply marginated thin-walled single or multiple areas of low attenuation that do not show enhancement on postcontrast images. Small, linear, peripheral calcifications may be present (3). On MR images, lymphangiomas resemble cysts, with homogenous low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Areas of high signal intensity on T1-weighted images may be caused by large amounts of proteinaceous fluid in association with internal hemorrhage (3).
Hemangiopericytomas are rare vascular tumors that have a high rate of local recurrence and most commonly metastasize to the lung (3,9). Reported CT findings have included a large multilobulated mass with numerous other smaller lesions disseminated throughout the entire spleen. Postcontrast CT scans demonstrate contrast enhancement of the solid portions and internal septation of the tumor (3,9). These findings are similar to those for an angiosarcoma of the spleen.
Another rare benign splenic tumor that could mimic an angiosarcoma is hemangioendothelioma. Patients with this tumor have clinical symptoms similar to those of patients with angiosarcoma. Spontaneous rupture occurs in approximately one-third of the patients with epithelioid vascular tumors (3,24,25). On CT scans, these lesions appear as focal round or irregular areas of heterogeneous low attenuation. Occasionally, cystic or necrotic areas have been demonstrated (3,24). Results of MR imaging studies have shown, on both T1- and T2-weighted images, a mass with well-defined borders, a heterogeneous texture, and hypointense radial streaks, which represent fibrosis (25).
Lymphoma and metastatic disease frequently affect the spleen and could mimic a relatively avascular angiosarcoma. Splenomegaly is found in up to 80% of patients with lymphoma of the spleen (3). The CT appearance includes homogenous enhancement without a discrete mass, a solitary mass, multifocal lesions, and diffuse infiltration. The masses generally do not enhance and have lower attenuation than that of the surrounding splenic parenchyma (3,13). Enlarged abdominal lymph nodes may help in the diagnosis of lymphoma, as splenic angiosarcoma rarely metastasizes to abdominal lymph nodes. Some authors have reported that while splenic metastases are uncommon (4%–7% of cases), almost one-half of all metastases to the spleen are from melanoma; breast (21%) and lung (18%) are the next most common sites of primary tumor (3). While lesions can be solitary or multiple, other than the rare instance in melanoma, there are almost always widespread metastases to the liver and throughout the abdomen when there are splenic metastases (3). Thus, even though metastatic splenic lesions could mimic a relatively avascular angiosarcoma, the presence of other metastatic lesions in a patient with a known primary lesion is usually not a problem.
The diagnosis of splenic angiosarcoma can be made on the basis of results of fine-needle aspiration biopsy, as shown in this series. Successful fine-needle aspiration biopsy has been reported for littoral cell angioma (26). Preoperative knowledge of a diagnosis of angiosarcoma of the spleen may be useful in the treatment of those patients who do not have clinically important hypersplenism. Percutaneous imaging-guided biopsy of the spleen is often avoided, since the spleen is a highly vascular organ. Also, percutaneous biopsy of a vascular lesion such as an angiosarcoma in the spleen might increase the complication rate. However, in two recently published reviews (27,28) on imaging-guided percutaneous biopsy of the spleen, successful diagnosis was reported in 89% of patients in one review and in 91% of patients in the other. A higher complication rate (10.3%) has been reported among patients with refractory thrombocytopenia and vascular splenic neoplasms (27). To our knowledge, none of our patients had specific thrombocytopenia, but we did not have complete laboratory data for most of the patients. However, thrombocytopenia has been reported in over 15% of patients with angiosarcoma of the spleen (1). Therefore, a careful assessment of clotting function should be made prior to attempting to perform biopsy of a vascular tumor of the spleen such as an angiosarcoma.
There was an inherent limitation to our study that was based on the nature of the patients in a referral population. Our patients were examined at a number of different institutions over a 19-year period, although eight of the patients were examined after 1999. So, while the majority of our imaging studies were performed with reasonably modern US, CT, and MR equipment, there was still a lack of standardization, in terms of imaging protocols, for all modalities. Only two of the five patients examined with US underwent Doppler evaluations, and there was not a uniform technique for the intravenous administration of contrast material at CT or MR examinations. Seven of the 20 CT scans and all three MR examinations, but not all studies for which intravenous contrast material was administered, were performed during the late arterial or early portal venous phase. This was very important because our study involved a vascular neoplasm in a highly vascular organ. One additional limitation was that we had complete US, CT, or MR studies for only six of the 12 patients. For the other patients, a set of key images was available that allowed us to perform our analysis, but our interpretations were limited without the complete records. The final limitation of our study was the lack of modern CT workstation functionality for window settings in all but one case. It is possible that subtle splenic and liver lesions could have been overlooked without the ability to alter window and level settings. We had the ability to overcome these limitations because we were able to review complete clinical, pathologic, and surgical data in all patients to ensure our imaging interpretations were correct. In addition, we had correlative photographs of gross specimens in 10 patients.
In conclusion, the clinicopathologic features seen in our series of patients with angiosarcoma are consistent with those in the current medical literature. The most common cross-sectional imaging feature demonstrated in our study was an aggressive mass that diffusely infiltrated and enlarged the spleen. Metastases are frequently present at the time of diagnosis. The diagnosis of angiosarcoma can be suggested at imaging in 83% of patients.
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FOOTNOTES |
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The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Departments of the Army or Defense.
Author contributions: Guarantor of integrity of entire study, W.M.T.; study concepts and design, W.M.T.; literature research, W.M.T.; clinical studies, W.M.T., N.S.A., A.D.L.; data acquisition and analysis/interpretation, W.M.T., A.D.L.; manuscript preparation, W.M.T., A.D.L., L.G.; manuscript definition of intellectual content, W.M.T.; manuscript editing and revision/review, all authors; manuscript final version approval, W.M.T., A.D.L.
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTS DISCUSSIONREFERENCES |
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