Primary non-Hodgkin's splenic lymphoma.

OBJECTIVES: To describe the imaging, clinical and pathological features of primary splenic lymphoma using a strict definition. METHODS: Of 21 cases, plain films were available in nine, sonograms in 10 and CT in 16. We categorized the spleen as either normal, enlarged with no focal defects (type 1), studded with miliary masses (type 2), containing multifocal masses of varying size (1-10 cm) (type 3) or containing a solitary large mass >5 cm without (type 4A) or with (type 4B) central hypodensity/anechoic areas. RESULTS: Clinical presentations were left upper quadrant pain, weight loss and/or fever. One case was found incidentally on CT. Fourteen were type 4A, three type 4B, four type 3 and none were type 1 or 2. Nine of 10 cases were hypoechoic. In 11/12 cases with enhanced scans, the lesions are hypodense relative to the splenic parenchyma, and in one case, the lesion was necrotic. Rim enhancement was seen in one case. CONCLUSION: Primary splenic lymphoma usually presents as a mass or masses rather than with splenomegaly alone. Splenectomy may be required for diagnosis.

Duodenal gangliocytic paraganglioma: CT, MR imaging, and US findings.

PURPOSE: To determine the imaging features of duodenal gangliocytic paraganglioma that can be used to differentiate this mass from other lesions. MATERIALS AND METHODS: Imaging, histopathologic, and surgical findings in five patients with proved gangliocytic paraganglioma were reviewed. The most common symptom at presentation was abdominal pain (n = 3). All patients underwent computed tomography (CT), two underwent ultrasonography (US), and one underwent magnetic resonance (MR) imaging. Imaging findings were correlated with findings from surgical resection specimens in all cases. RESULTS: All lesions were located around the second portion of the duodenum and were 3-13 cm in diameter (mean, 6.5 cm). Two extended laterally to the duodenum, two extended medially, and one was intraluminal. All appeared solid and homogeneous on US, CT, and MR images and had homogeneous contrast material enhancement on CT and MR images. All were solid, with a prominent vascular network, but no cystic hemorrhage or necrosis was noted at pathologic examination. CONCLUSION: The imaging features of gangliocytic paraganglioma are suggestive enough for the prospective diagnosis and differentiation of this benign mass from other lesions.

Undifferentiated (embryonal) sarcoma of the liver: pathologic basis of imaging findings in 28 cases.

PURPOSE: To correlate the imaging and pathologic features of undifferentiated (embryonal) sarcoma (UES) and account for the discrepancy between the solid appearance at ultrasound (US) and the almost cystlike appearance at computed tomography (CT) and magnetic resonance (MR) imaging. MATERIALS AND METHODS: The clinical, pathologic, and imaging findings in 28 patients (age range, 3-49 years) with pathologically proved UES were retrospectively reviewed. All patients underwent at least one cross-sectional imaging study to include CT (27 patients), US (21 patients), and MR imaging (six patients). Tumor size, gross morphology (n = 27), histologic features, and proportion of solid and cystlike components were evaluated and correlated to the imaging findings. RESULTS: The mean transverse diameter of the tumors was 14 cm (range, 10-25 cm). At gross examination, the tumors were predominantly solid (mean, 83% of tumor volume), and pathologic and US findings were concordant. Conversely, CT scans showed low attenuation (approximately that of water) in 88% of the tumor volume and T2-weighted MR images showed high signal intensity (approximately equal to that of cerebrospinal fluid) in 89% of the tumor volume. CONCLUSION: UES shows a misleading cystlike appearance at CT and MR imaging compared with US and pathologic findings. In a child or young adult with a liver tumor, this finding is useful in making a prospective diagnosis and avoiding misguided attempts at drainage.

Islet cell tumors of the pancreas: clinical, radiologic, and pathologic correlation in diagnosis and localization.

Islet cell tumors are rare pancreatic or peripancreatic neoplasms that produce and secrete hormones to a variable degree. These tumors are best divided on clinical grounds into those that produce a recognizable, clinically evident endocrine syndrome (ie, functioning) and those that exhibit no clinical evidence of hormone production (ie, clinically silent). Clinically silent tumors produce symptoms due to mass effect because of their large size. They are often partially cystic or necrotic. Functioning islet cell tumors usually manifest earlier in the course of the disease because of the distinctive signs and symptoms of the associated endocrine syndrome. Clinically silent and functioning tumors cannot be histologically distinguished reliably even with the use of immunohistochemical stains. Insulinoma and gastrinoma, the two most common functioning lesions, are typically small homogeneous masses. Other functioning islet cell tumors include glucagonoma, somatostatinoma, vipoma, and adrenocorticotropic hormone-producing tumor. Larger tumors are associated with calcification, cystic degeneration and necrosis, and a more aggressive behavior (local and vascular invasion as well as distant metastases). There are many different techniques for detection and characterization of these lesions that are usually chosen according to the radiologist's experience and preference. Treatment and prognosis of these lesions depend on the hormone produced, their size, and their behavior.

Meckel's enteroliths: clinical, radiologic, and pathologic findings.

OBJECTIVE: The objective of this study was to determine the clinical, radiographic, and pathologic findings of Meckel's enteroliths, a rare complication of Meckel's diverticulum. MATERIALS AND METHODS: Of 84 cases of Meckel's diverticulum, eight (10%) were found at surgery to contain enteroliths. Abdominal radiographs and barium studies of these eight patients were reviewed retrospectively. Medical and pathologic records were also reviewed. RESULTS: At the time of diagnosis, the median age of the eight patients with Meckel's enteroliths was 45 years old. Six patients were male, and two were female. All eight patients were symptomatic, but symptoms were chronic in six patients (75%). Meckel's enteroliths were seen on abdominal radiographs in seven patients (88%). The stones had an average diameter of 3 cm (range, 1-5 cm). Five patients had multiple opaque stones, and two patient had solitary stones (total number of stones, 18). Sixteen of the enteroliths were revealed as peripheral calcified stones with radiolucent centers; two were revealed as laminated stones. One patient had a Meckel's stone ileus due to extrusion of an enterolith into the lumen that subsequently caused small-bowel obstruction. Histologically, all Meckel's diverticula with enteroliths contained intestinal mucosa lining without ectopic gastric mucosa. CONCLUSION: Meckel's enteroliths are a rare complication of Meckel's diverticulum. Nevertheless, this entity should be included in the differential diagnosis of abdominal calcification when a peripheral calcified stone or, less commonly, a laminated stone is detected in the lower abdomen on radiographs of adults with chronic abdominal pain or gastrointestinal blood loss.

Non-Hodgkin lymphoma of the stomach: a cause of linitis plastica.

PURPOSE: To demonstrate the radiologic appearance of linitis plastica in non-Hodgkin lymphoma of the stomach and to correlate radiologic and pathologic findings. MATERIALS AND METHODS: Of 34 cases of non-Hodgkin lymphoma of the stomach in the radiologic archives of the Armed Forces Institute of Pathology, nine had a linitis plastica appearance at barium study. The radiologic, endoscopic, and pathologic findings of these cases were reviewed. RESULTS: All nine patients (six with primary gastric lymphoma, three with generalized lymphoma with stomach involvement) were symptomatic. Images from barium studies revealed a linitis plastica appearance with narrowing of the gastric antrum and/or body (n = 5), narrowing of the body and/or fundus (n = 3), and diffuse gastric narrowing (n = 1). On CT scans (n = 7), marked circumferential soft-tissue thickening (average thickness, 2.9 cm) of the gastric wall was seen. Patients were treated with subtotal gastrectomy and gastrojejunostomy (n = 5) or total gastrectomy and esophagojejunostomy (n = 4). In all cases, histopathologic specimens revealed a thickened gastric wall with lymphomatous cell infiltration. Wall thickening was associated with areas of fibrosis in only one case. CONCLUSION: Non-Hodgkin gastric lymphoma should be recognized as another cause of linitis plastica, especially in patients with a history of lymphoma or evidence of generalized lymphoma at presentation.

Leiomyosarcoma of the esophagus: radiographic findings in 10 patients.

OBJECTIVE: Leiomyosarcomas of the esophagus are rare malignant smooth-muscle tumors that have been described only anecdotally in the radiology literature. The objective of this study was to evaluate the clinical and radiographic findings of this unusual lesion. MATERIALS AND METHODS: A search of the radiology archives of the Armed Forces Institute of Pathology revealed 10 cases of esophageal leiomyosarcomas. Clinical and radiographic findings were reviewed retrospectively. RESULTS: All but one patient presented with dysphagia. The average duration of the dysphagia was 6.7 months, but five patients had dysphagia for 3 or fewer months. Frontal chest radiographs revealed a mediastinal mass in five patients. Barium studies revealed intramural lesions in six patients, intraluminal lesions in two, and infiltrative lesions in two. The intramural Lesions all had large exophytic components, and three contained ulceration or tracking. One of the intraluminal lesions appeared as a polypoid expansile mass and the other, as a smooth expansile sausage-shaped mass mimicking a fibrovascular polyp. CT revealed a mass involving the esophagus in five patients; three of these patients had heterogeneous lesions containing large exophytic components, central areas of low density, and extraluminal gas or contrast material within the tumor. In two patients, MR imaging revealed large masses that were isointense with skeletal muscle on T1-weighted images and hyperintense on T2-weighted images. CONCLUSION: Our experience suggests that esophageal leiomyosarcomas have radiographic findings similar to those of leiomyosarcomas elsewhere in the gastrointestinal tract. Esophageal leiomyosarcomas have a better prognosis than squamous cell carcinomas and are often amenable to surgical cure.

Inverted Meckel diverticulum: clinical, radiologic, and pathologic findings.

PURPOSE: To determine the clinical, radiologic, and pathologic findings of inverted Meckel diverticulum by retrospectively reviewing a large series of cases. MATERIALS AND METHODS: Among 84 cases of Meckel diverticulum, 18 (21%) were found at surgery to be inverted into the lumen of the bowel. Thirteen of these 18 (72%) cases were associated with small bowel intussusception and five (28%) were not. RESULTS: All 18 patients (median age at time of diagnosis, 32 years) were symptomatic, but the symptoms were subacute or chronic in 14 (78%). At barium examination in 15 cases, inverted diverticulum was depicted in 10 (67%) as a solitary, elongated, smoothly marginated, often club-shaped intraluminal mass in the distal ileum. At computed tomography (CT) in three cases, a central area of fat attenuation was surrounded by a thick collar of soft-tissue attenuation. At ultrasound (US) in two cases, a target-like mass contained a central area of increased echogenicity. At pathologic examination in all cases, the inverted sac contained mesenteric fat. CONCLUSION: Inverted Meckel diverticulum occurs more commonly than previously recognized and is associated with characteristic findings at barium examination, CT, and US.

Solid and papillary epithelial neoplasm of the pancreas: imaging-pathologic correlation on 56 cases.

PURPOSE: To evaluate the clinical, pathologic, and imaging findings of solid and papillary epithelial neoplasm (SPEN) of the pancreas and to correlate imaging and gross pathologic features. MATERIALS AND METHODS: A retrospective review was performed in 56 patients (53 female and three male patients aged 10-74 years [mean age at diagnosis, 25 years]) with pathologically proven SPEN of the pancreas. All patients underwent computed tomography (n = 49), ultrasonography (n = 31), or magnetic resonance (MR) imaging (n = 9). Tumor size, location, and imaging features were evaluated and correlated with gross pathologic and histologic features. RESULTS: Mean transverse diameter of these tumors was 9.0 cm (range, 2.5-17.0 cm). They were localized to the tail (n = 30), head (n = 18), and body (n = 8) of the pancreas. All tumors contained some degree of internal hemorrhage or cystic degeneration, and all were well encapsulated. Areas of hemorrhagic degeneration ranged from solid friable tumor to gelatinous or cystic cavities and therefore demonstrated variable imaging features. Calcification was noted in 16 patients. Fluid-debris levels were noted in 10 patients. CONCLUSION: Imaging studies of SPEN of the pancreas consistently demonstrate variable degrees of hemorrhagic degeneration. Calcification is common. Characteristic fluid-debris levels and signal intensities seen with MR imaging indicate blood products. In the appropriate clinical setting, these findings are useful in making a prospective diagnosis.

Small-cell carcinoma of the esophagus: radiographic findings.

PURPOSE: To determine the radiographic findings of small-cell carcinoma of the esophagus. MATERIALS AND METHODS: The authors retrospectively reviewed barium studies as well as medical and pathologic records for three cases of small-cell carcinoma of the esophagus contributed to the radiologic archives of the Armed Forces Institute of Pathology. RESULTS: Two patients presented with dysphagia and one with chest pain. In all three patients, barium studies revealed a smoothly marginated, sessile mass with a relatively flat central ulcer on the right postero-lateral wall of the midesophagus below the level of the carina. The masses all were 4-5 cm in diameter, and the ulcers were 2-3 cm in diameter. In all three patients, the results of endoscopy confirmed the presence of a sessile mass with central ulceration in the midesophagus. CONCLUSION: Small-cell carcinomas of the esophagus can have similar findings on barium studies. Although these findings are more likely to be caused by squamous-cell carcinoma, it is important to obtain endoscopic biopsy specimens, because preoperative histologic diagnosis of small-cell carcinoma can dramatically alter the management of these cases.

Esophageal leiomyomatosis.

PURPOSE: To reassess the clinical and radiologic findings in patients with esophageal leiomyomatosis. MATERIALS AND METHODS: A search of the authors' radiologic archives revealed six cases of esophageal leiomyomatosis in a 22-year period. The clinical findings and radiologic images were reviewed retrospectively. RESULTS: The average age of the patients was 10.8 years (range, 6-18 years). Five patients presented with slowly progressive dysphagia. Barium studies revealed smooth, tapered narrowing of the distal esophagus in five patients and characteristic defects on the superomedial aspect of the gastric fundus abutting the cardia, presumably due to bulging of this thickened mass of muscle into the stomach, in four patients. In two patients, computed tomography (CT) revealed marked thickening of the distal esophageal wall. CONCLUSION: Esophageal leiomyomatosis can be suggested in a pediatric patient with long-standing dysphagia in whom smooth, tapered distal esophageal narrowing is seen at barium study and circumferential esophageal wall thickening is seen at CT.

Fibrovascular polyps of the esophagus: clinical, radiographic, and pathologic findings in 16 patients.

OBJECTIVE: Fibrovascular polyps of the esophagus are rare benign nonneoplastic intraluminal masses. Most published reports of patients with these polyps have been anecdotal. The purpose of this study was to reassess the clinical, radiographic, and pathologic findings in a relatively large series of patients with this unusual tumorlike lesion. MATERIALS AND METHODS: A search of the radiologic archives of the Armed Forces Institute of Pathology revealed 16 cases of fibrovascular polyps of the esophagus. We reviewed the clinical, radiographic, and pathologic findings in these 16 cases. RESULTS: All 16 patients were symptomatic. Fourteen (87%) had dysphagia and four (25%) had respiratory symptoms. The average duration of symptoms was 17 months, but seven patients (44%) had symptoms for 6 or fewer months. Two patients (12%) had a history of regurgitating the tumor into the pharynx or mouth, but none had the known complication of asphyxiation due to occlusion of the larynx. Chest radiographs revealed a right-sided superior mediastinal mass and/or anterior tracheal bowing in seven patients (44%). Barium studies revealed smooth but variably lobulated intraluminal masses that originated in the lower cervical esophagus and had variable sizes and distal extents, with an average length of 15 cm. Depending on the amount of fat and fibrovascular tissue in the lesion, CT revealed a heterogeneous appearance in four patients, lesions of predominantly fat density in two, and lesions of predominantly soft-tissue density in two. CONCLUSION: Knowledge of the clinical and radiographic features of fibrovascular polyps of the esophagus is important because surgical removal of these lesions is warranted in most patients.

Focal nodular hyperplasia of the liver: radiologic-pathologic correlation.

Focal nodular hyperplasia (FNH) is a benign hepatic tumor that likely represents a local hyperplastic response of hepatocytes to a congenital vascular anomaly. It is most commonly seen in middle-aged women and is typically a solid mass measuring less than 5 cm in diameter. Most lesions have central scars that contain thick-walled vessels that provide excellent arterial blood supply; hemorrhage, necrosis, and infarction are, therefore, extremely unusual. Characteristic imaging features include a hypervascular homogeneous tumor with a central scar and with both hepatocellular and reticuloendothelial function. Ultrasonography, computed tomography, scintigraphy, and magnetic resonance imaging all offer different advantages in the detection and characterization of FNH. There is excellent correlation between the pathologic and imaging features of FNH. In many cases, it is possible to obtain a prospective imaging diagnosis of FNH; however, in some cases, the distinction between FNH and other primary hepatic neoplasms is not possible. In these latter cases, close imaging follow-up, needle biopsy, or even surgical resection may be necessary.

Intussuscepted colonic lipomas: loss of fat attenuation on CT with pathologic correlation in 10 cases.

BACKGROUND: To determine if infarction and necrosis is the cause of the confusing soft tissue density on CT within intussuscepting lipomas of the colon. METHODS: The clinical records, radiologic examinations, and pathologic specimens of all 13 cases of colonic lipomas collected from 1988 to 1994 studied by CT and surgically resected were retrospectively reviewed. Ten of these cases were associated with intussusception; the CT attenuation of the lead point was graded according to its relative fat/soft tissue density. Pathologic specimens were graded independently by a GI pathologist and graded according to the degree of infarction/fat necrosis. RESULTS: The lipomas ranged from 4 to 7 cm in diameter (mean = 5 cm). Only one case with intussusception, and all three cases without, demonstrated pure fat attenuation on CT and demonstrated pure fat histologically. One case demonstrated soft tissue attenuation and corresponded with the most severely infarcted specimen histologically; two cases with similar but less severe infarction/fat necrosis corresponded with less than 25% fat attenuation. These latter three cases were originally misinterpreted as malignancies rather than lipomas. Six cases maintained greater than 50% fat density and intermediate amounts of infarction/fat necrosis. CONCLUSION: Lipomas may have an atypical appearance when intussuscepted due to varying degrees of infarction/fat necrosis.

Islet cell tumors of the pancreas: pathologic-imaging correlation among size, necrosis and cysts, calcification, malignant behavior, and functional status.

OBJECTIVE: The purpose of our study was to correlate the imaging and pathologic features of islet cell tumors with regard to tumor size, necrosis and cysts, calcification, malignant behavior, and functional status. MATERIALS AND METHODS: We retrospectively reviewed the clinical, pathologic, and imaging features of all 133 cases of pathologically proved islet cell tumors of the pancreas seen at the Armed Forces Institute of Pathology. Clinical data, including the patients' symptoms and serologic characteristics, were used to distinguish hyperfunctioning tumors (those causing symptoms related to elevated serum polypeptide levels) from nonhyperfunctioning tumors; hyperfunctioning tumors were divided further into insulin-producing and non-insulin-producing types. All patients had at least one cross-sectional imaging study, including CT (n = 118), sonography (n = 42), or MR imaging (n = 22). Clinical, pathologic, and imaging features were evaluated and correlated with tumor size, necrosis and cysts, calcification, local invasion, vascular invasion, metastases, and functional status. RESULTS: Islet cell tumors with areas of necrosis or cystic change found pathologically and on imaging studies (56/133) were larger (8.4 cm in mean transverse diameter) than homogeneous solid lesions (2.9 cm in mean transverse diameter) and were predominantly non-insulin producing (48/56) and nonhyperfunctioning (36/56). Of the 43 insulinomas, 35 were small (2.2 cm in mean transverse diameter), solid, and homogeneous. Larger size also was associated with calcification and malignant behavior, including local invasion, vascular invasion, and distant metastases. CONCLUSION: Our findings show that cystic and necrotic islet cell tumors are usually non-insulin-producing and nonhyperfunctioning neoplasms and larger than the typically solid and small insulinomas. Calcification, local invasion, vascular invasion, and metastatic disease are more commonly seen with larger neoplasms.

Biliary cystadenoma and cystadenocarcinoma: clinical-imaging-pathologic correlations with emphasis on the importance of ovarian stroma.

PURPOSE: To evaluate cross-sectional imaging in the distinction of biliary cystadenoma from cystadenocarcinoma and in the determination of the presence of ovarian stroma. MATERIALS AND METHODS: In 34 patients, radiologic studies and specimen photographs and descriptions were reviewed retrospectively without knowledge of the patient group. Histologic features were reviewed without knowledge of the radiologic findings and analyzed for epithelial and stromal components. Correlation was made between the radiologic findings, gross morphologic features, internal fluid characteristics, and histologic features. RESULTS: The 34 patients had 27 biliary cystadenomas, 22 with ovarian stroma, and seven cystadenocarcinomas, four with ovarian stroma. Gross morphologic and imaging features suggestive of biliary cystadenocarcinoma included internal septation and nodularity. Septation without nodularity was seen only in biliary cystadenoma. Nonbilious fluid was the only feature associated with the presence of ovarian stroma but was not distinguishable on images. CONCLUSION: Imaging studies accurately reflect the nodularity and septation seen grossly to distinguish biliary cystadenoma and cystadenocarcinoma but do not allow distinction of the presence or absence of ovarian stroma.

Gastrointestinal manifestations of acquired immunodeficiency syndrome: radiologic-pathologic correlation.

Gastrointestinal diseases are common in patients with the acquired immunodeficiency syndrome (AIDS). In this review, the radiologic and pathologic findings of these diseases in AIDS patients are illustrated with cases from the archives of the Armed Forces Institute of Pathology. Diseases are categorized in two etiologic groups, opportunistic infections and AIDS-related neoplasms. Opportunistic infections include those caused by viral, fungal, protozoan, and bacterial pathogens. The AIDS-related neoplasms of primary importance are Kaposi sarcoma and non-Hodgkin lymphoma. The radiologic findings of these gastrointestinal diseases are frequently nonspecific. However, interpretation of the images with knowledge of the underlying pathologic entities and the level of compromise of the immune system helps narrow the differential diagnosis and often helps identify the presumptive diagnosis.

The hamartomatous polyposis syndromes: clinical and radiologic features.

Most radiologists are familiar with the clinical and radiologic features of the familial adenomatous polyposis syndromes [1]. The hamartomatous polyposis syndromes occur less frequently, however, and their radiologic and clinical manifestations are not as well known. This group of syndromes includes Peutz-Jeghers, multiple hamartoma, juvenile polyposis, Cronkhite-Canada, and Bannayan-Riley-Ruvalcaba. The predominant gastrointestinal lesion in these diseases is some form of hamartomatous polyp. The term hamartoma implies a nonneoplastic tumor or tumorlike condition composed of tissue elements normally present in the particular area [2]. In many of these syndromes, it is now recognized that hamartomatous polyps of the gastrointestinal tract coexist with adenomas and that adenomas may develop within hamartomatous polyps. Either situation may contribute to the frequent association of alimentary tract adenocarcinoma that occurs in most of these syndromes. Various types of benign mucocutaneous lesions are common and often lead to the correct diagnosis. Of greater importance is the frequent occurrence of other extraintestinal manifestations, including several forms of malignant disease. Because of this frequent association with both gastrointestinal and nongastrointestinal malignant tumors, early and accurate diagnosis of these syndromes is essential. Meticulously performed double contrast studies are the preferred radiologic procedures for the diagnosis of gastrointestinal polyps in all of these diseases.

Calcification and fibrosis in mesenteric carcinoid tumor: CT findings and pathologic correlation.

OBJECTIVE: The purposes of this study were to determine the frequency and characteristics of calcification and fibrosis in mesenteric carcinoid tumor as seen on CT scans and to evaluate their possible role in diagnosis. MATERIALS AND METHODS: The CT findings in 29 cases of proved mesenteric carcinoid tumor were analyzed retrospectively. Tumors were assessed for size, margin, density, radiating strands, calcification, and associated thickening of the small-bowel wall. Matching histologic sections were available for 21 of the cases. They were reviewed independently for histologic pattern, degree of fibrosis, degree of infiltration along neurovascular bundles, necrosis, lymph node architecture, and calcification or ossification within the mass. CT and pathologic findings were then assessed for possible relationships. RESULTS: Calcification was detected by CT in 70% (21 of 30) of mesenteric masses. Three patterns of calcification were noted: small, stippled calcification (n = 11); coarse, dense calcification (n = 7); and diffuse calcification (n = 3). All calcification was localized within areas of poorly cellular mature fibrous tissue. The degree of radiating strands detected by CT tended to increase with the degree of fibrosis seen histopathologically (p = .06). CONCLUSION: Calcification in mesenteric carcinoid tumors was observed by CT in most cases of this series. The triad of a calcified mesenteric mass, radiating strands, and adjacent bowel-wall thickening should be considered highly suggestive of carcinoid tumor.