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.

Congenital brain tumors: a review of 45 cases.

Forty-five pathologically proved cases of neonatal brain tumors (diagnosed in neonates within 60 days after birth) were reviewed from the neuroradiology archives dating back to 1964. CT was performed in 24 cases, MR in five, sonography in six, and angiography in seven. Two-thirds of the lesions were supratentorial. The most common histology was a tumor composed of primitive or poorly differentiated tissues: 12 teratomas and 12 primitive neuroectodermal tumors, four of which were typical medulloblastomas. In addition, there were nine astrocytomas (grades I-III); four cases of glioblastoma multiforme (astrocytoma grade IV); three choroid plexus papillomas; and single cases each of ependymoma, medulloepithelioma, germinoma, angioblastic meningioma, and ganglioglioma. The dominant CT appearance, regardless of histology, was a large heterogeneous lesion with associated hydrocephalus. Coarse calcification was a constant feature in the teratomas. Prognosis was poor overall, with the longest survival seen in choroid plexus papilloma and astrocytoma. Imaging studies are most valuable in identifying and distinguishing potentially curable lesions such as choroid plexus papillomas (variably sized intraventricular lesions with homogeneous enhancement) from rapidly fatal tumors such as teratomas (large heterogeneous lesions with coarse calcifications and associated hydrocephalus).

Giant-cell tumor of the tibia in a child presenting as an expansile metaphyseal lesion with fluid-fluid levels on MR.

Approximately two percent of giant-cell tumors (GCT) occur in the skeletally immature. The patient presented is four years old with a cystic giant-cell tumor of the tibial metaphysis. Fluid-fluid levels are demonstrated on CT and MR and likely represent the underlying pathophysiology.

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.

Congenital brain tumors: a review of 45 cases.

Forty-five pathologically proved cases of neonatal brain tumors (diagnosed in neonates within 60 days after birth) were reviewed from the neuroradiology archives dating back to 1964. CT was performed in 24 cases, MR in five, sonography in six, and angiography in seven. Two-thirds of the lesions were supratentorial. The most common histology was a tumor composed of primitive or poorly differentiated tissues: 12 teratomas and 12 primitive neuroectodermal tumors, four of which were typical medulloblastomas. In addition, there were nine astrocytomas (grades I-III); four cases of glioblastoma multiforme (astrocytoma grade IV); three choroid plexus papillomas; and single cases each of ependymoma, medulloepithelioma, germinoma, angioblastic meningioma, and ganglioglioma. The dominant CT appearance, regardless of histology, was a large heterogeneous lesion with associated hydrocephalus. Coarse calcification was a constant feature in the teratomas. Prognosis was poor overall, with the longest survival seen in choroid plexus papilloma and astrocytoma. Imaging studies are most valuable in identifying and distinguishing potentially curable lesions such as choroid plexus papillomas (variably sized intraventricular lesions with homogeneous enhancement) from rapidly fatal tumors such as teratomas (large heterogeneous lesions with coarse calcifications and associated hydrocephalus).

Typical, atypical, and misleading features in meningioma.

Meningiomas are the most common nonglial primary tumors of the central nervous system and the most common extraaxial neoplasms, accounting for approximately 15% of all intracranial tumors. They are usually benign neoplasms, with characteristic pathologic and imaging features. However, there are several important histologic variants of meningioma, and even a histologically typical meningioma can have unusual or misleading radiologic features that may not be suggestive of meningioma. The typical meningioma is a homogeneous, hemispheric, markedly enhancing extraaxial mass located over the cerebral convexity, in the parasagittal region, or arising from the sphenoid wing. Meningiomas may originate in unexpected locations such as the orbit, paranasal sinus, or ventricles or be entirely intraosseous (within the calvaria). Unusual imaging features such as large meningeal cysts, ring enhancement, and various metaplastic changes (including fatty transformation) can be particularly misleading. Because meningiomas are so common, the radiologist must be aware of their less frequent and uncharacteristic imaging features in order to suggest the correct diagnosis in cases that are atypical.

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.

Malignant vascular tumors of the liver: radiologic-pathologic correlation.

Although benign vascular tumors of the liver are extremely common (hemangioma is the most common), malignant vascular tumors of the liver are very rare. In the adult, these tumors are angiosarcoma, epithelioid hemangioendothelioma, and Kaposi sarcoma. All hepatic malignant vascular tumors share histologic characteristics, grow around and into vessels, and are grossly multifocal. They may be misdiagnosed histologically, particularly if only a biopsy sample is available. Although imaging findings are often non-specific, some features are suggestive or even characteristic of these neoplasms. Such features include previous exposure to thorium dioxide (Thorotrast) in cases of angiosarcoma, coalescence of multiple nodules into large peripheral masses in epithelioid hemangioendothelioma, and association between acquired immunodeficiency syndrome and cutaneous involvement in Kaposi sarcoma. Because hepatic malignant vascular tumors are often multiple, the main differential diagnosis is metastatic disease. There is no effective treatment for these tumors, and although survival time is variable, the prognosis is generally unfavorable.

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.

Diffuse disease of the liver: radiologic-pathologic correlation.

Cross-sectional imaging is playing an increasing role in diagnosis of diffuse liver diseases because it clarifies, in many cases, the overlap in clinical and laboratory manifestations often present in diffuse hepatic processes and thus may eliminate the need for a biopsy. Advances in cross-sectional imaging, particularly in magnetic resonance (MR) imaging, enable further characterization of hepatic parenchymal and architectural changes, allowing closer correlation with underlying pathologic changes. Advanced imaging techniques can be used to characterize a variety of metabolic, vascular, toxic, infectious, and neoplastic diffuse liver diseases. These include more common entities such as cirrhosis, Budd-Chiari syndrome, hemochromatosis, Wilson disease, fatty change, and diffuse neoplastic disease (hepatocellular carcinoma, metastasis, and lymphoma) and uncommon entities such as schistosomiasis, sarcoidosis, and amyloidosis. Correlation of computed tomographic and MR imaging findings with underlying pathologic features is helpful in understanding the gamut of diffuse diseases of the liver.

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.

Intramuscular myxoma: MR features.

Intramuscular myxoma is a benign mesenchymal lesion consisting of bland spindled cells embedded in an avascular myxoid stroma. On CT, intramuscular myxoma presents as a well-demarcated, homogeneous, low density mass situated within skeletal muscle. The attenuation of the lesion is slightly greater than water but less than that of the surrounding normal muscle, with typical values between +10 and +60 HU. There is scant magnetic resonance (MR) literature on the appearance of intramuscular myxoma; the few MR spin echo images that have been published characterize it as a homogeneous mass with signal intensity less than or equal to skeletal muscle on T1-weighted and brighter than fat on T2-weighted pulse sequences. We present two cases of intramuscular myxoma with imaging characteristics that differ from those previously reported.

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.

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.

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.

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.