The Rocky liver: radiologic-pathologic correlation of calcified hepatic masses.

Although relatively uncommon in daily clinical practice, calcification may be found in inflammatory hepatic lesions and in benign and malignant liver neoplasms. The most common source of calcified hepatic lesions is inflammatory conditions such as granulomatous diseases (e.g., tuberculosis). The calcification typically involves the entire lesion and appears as a dense mass that can produce artifacts on computed tomographic (CT) scans. Echinococcus cysts have curvilinear or ring calcification. Hemangiomas, especially large ones, may contain large, coarse calcifications that are centrally located in areas of fibrosis; these may be seen at CT (20% of cases) or radiography (10%). In hepatocellular adenoma, calcifications may be solitary or multiple and are usually located eccentrically within a complex heterogeneous mass. Calcifications in fibrolamellar carcinoma have been reported in 15%-25% of cases at CT and occur in a wide variety of patterns. Calcifications in intrahepatic cholangiocarcinoma are typically accompanied by a desmoplastic reaction and are visible at CT in about 18% of cases. Calcified hepatic metastases are most frequently associated with mucin-producing neoplasms such as colon carcinoma. Knowledge of the pathologic features of each entity helps radiologists to better recognize the shape, size, density, number, location, and distribution of hepatic calcifications seen on images and to narrow the differential diagnosis.

From the Archives of the AFIP. Mucinous cystic neoplasms of the pancreas: radiologic-pathologic correlation.

Mucinous cystic neoplasms of the pancreas are rare primary tumors. They have pathologic and clinical similarities to biliary cystadenomas of the liver and mucinous cystic tumors of the ovary. Mucinous cystic neoplasms of the pancreas typically affect middle-aged women and arise in the tail of the pancreas. Gross pathologic and imaging features usually are those of a large, multilocular cystic mass. There is, however, a spectrum of radiologic findings that overlaps with those of other entities including pancreatic pseudocyst, other primary epithelial and nonepithelial tumors of the pancreas, and metastases. In most cases, ultrasound and computed tomography are the mainstays for radiologic evaluation, with magnetic resonance imaging having a complementary role. All mucinous cystic neoplasms should be considered as mucinous cystadenocarcinomas of low-grade malignant potential. Complete surgical excision alone results in an excellent clinical outcome and disease-free survival, irrespective of histologic or radiologic parameters in over 90% of cases studied.

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.

MR imaging of the liver. Primary malignant neoplasms in the adult.

Primary malignant liver neoplasms of the adult are discussed with emphasis on hepatocellular carcinoma, the most common neoplasm. The clinical and pathologic aspects of the following neoplasms are correlated with imaging features: hepatocellular carcinoma, fibrolamellar carcinoma, intrahepatic cholangiocarcinoma, angiosarcoma, epithelial hemangioendothelioma, other sarcomas, and lymphoma. The complementary role of ultrasound, CT, and MR imaging in characterizing these lesions and determining resectability is highlighted.

Imaging of pediatric liver tumors.

Primary pediatric liver tumors are a unique group of neoplasms. The age at presentation, clinical sigma symptoms, and imaging characteristics provide helpful clues in making a prospective diagnosis and in tailoring a differential diagnosis. The role of imaging is fourfold: characterization, localization, determination of resectability, and follow-up use. MR is usually complementary to ultrasound and CT.

Pancreatic neoplasms: MR imaging and pathologic correlation.

Magnetic resonance (MR) imaging can aid in the detection and characterization of many pancreatic neoplasms. The MR imaging appearances of common pancreatic neoplasms such as ductal adenocarcinoma are well-known. However, MR imaging features of more unusual pancreatic neoplasms are not well understood. Such tumors include mucin-hyper-secreting carcinoma, serous microcystic neoplasm, mucinous macrocystic neoplasm, solid and papillary epithelial neoplasm, multiple cysts associated with von Hippel-Lindau disease, acinar cell carcinoma, pancreaticoblastoma, and endocrine neoplasms (eg, nonfunctioning islet cell tumors, insulinoma, and gastrinoma). In general, pancreatic neoplasms demonstrate high signal intensity on T2-weighted images; the signal intensity on T1-weighted images is more variable but is often intermediate or low. Gadolinium enhancement is often helpful in further characterizing pancreatic neoplasms. The gross and histologic features of pancreatic neoplasms are also not well-known. Correlation with the underlying pathologic features enhances understanding of the MR imaging characteristics of both common and unusual pancreatic neoplasms.

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.

Pancreatic mucinous cystic neoplasm with sarcomatous stroma: a report of three cases.

Three patients with pancreatic mucinous cystic neoplasms having a sarcomatous stroma are reported. The tumors occurred in two women and one man, aged 48, 66, and 67 years, respectively. Symptoms included epigastric pain or a palpable abdominal mass or both. Radiographically, all the tumors were large, multicystic, and located in the tail of the pancreas. Histologically, the cystic component was lined by mucin-producing, columnar to cuboidal epithelium composed of benign to atypical to overtly malignant cells (cystadenocarcinoma). Immunohistochemistry showed the epithelial component of all three tumors to be positive with cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and the pancreatic epithelial mucin antibodies CA 19-9 and DUPAN 2. In all three cases, an undifferentiated malignant spindle cell (sarcomatous) stroma was intimately associated with the epithelial component. The sarcomatous component showed variable reactivity with vimentin (all three cases), muscle-specific and smooth-muscle actin (all three cases), S-100 protein (1/3), Leu-7 (one case), and estrogen and progesterone receptors (in two cases). Two patients died with widespread abdominal disease within 15 months of diagnosis, one of whom had an omental metastasis entirely composed of the sarcomatous stroma. The third patient was alive and free of disease at 16 months after diagnosis. Our findings document the existence of a sarcomatous component in pancreatic mucinous cystic neoplasms; this component appears to be responsible for the highly malignant behavior of the tumors.

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.