Biomedical subjects

Angela D Levy

Publications and source records attributed to Angela D Levy.

26 records · Page 2Linked to original sources

PubMedDate not supplied

From the archives of the AFIP. Benign tumors and tumorlike lesions of the gallbladder and extrahepatic bile ducts: radiologic-pathologic correlation. Armed Forces Institute of Pathology.

A diverse spectrum of benign tumors and tumorlike lesions arises from the gallbladder and bile ducts, and despite their diversity, these lesions share common embryologic origins and histologic characteristics. Although these lesions are relatively uncommon, their importance lies in their ability to mimic malignant lesions in these locations. Benign neoplasms are derived from the epithelial and nonepithelial structures that compose the normal gallbladder and bile ducts. The epithelium gives rise to adenomas, cystadenomas, and the unusual condition of biliary papillomatosis. Granular cell tumors, neurofibromas, ganglioneuromas, paragangliomas, and leiomyomas are examples of benign tumors that may originate from nonepithelial structures. Tumorlike lesions are more commonly found in the gallbladder and include xanthogranulomatous cholecystitis, adenomyomatous hyperplasia, cholesterol polyps, and heterotopias. In the clinical setting of a patient with nonspecific abdominal complaints or symptoms of biliary obstruction, the discovery of a gallbladder or bile duct polyp or mass, gallbladder wall thickening, or biliary stricture is most often indicative of malignancy. However, the differential diagnosis should include benign tumors and tumorlike lesions. The preoperative determination of a benign lesion may significantly alter therapy and patient prognosis.

Bile Duct Diseases↗

PubMedDate not supplied

Emphysematous infections of the abdomen and pelvis: a pictorial review.

Emphysematous (gas-forming) infections of the abdomen and pelvis represent potentially life-threatening conditions that require aggressive medical and often surgical management. The initial clinical manifestation of these entities may be insidious, but rapid progression to sepsis will occur in the absence of early therapeutic intervention. Conventional radiography and ultrasonography are often the initial imaging modalities used to evaluate patients with abdominopelvic complaints. However, when a differential diagnosis remains, or if further localization or confirmation of tentative findings is needed, computed tomography (CT) should be considered the imaging modality of choice. CT is both highly sensitive and specific in the detection of abnormal gas and well suited to reliable depiction of the anatomic location and extent of the gas. Of equal importance may be the capability of CT to help reliably identify benign sources of gas, because treatment (if any) varies dramatically depending on the source. Knowledge of the pathophysiologic characteristics, common predisposing conditions, and typical imaging features associated with gas-forming infections of the gallbladder, stomach, pancreas, and genitourinary system will help make early diagnosis and successful treatment possible. In addition, such knowledge will aid in further diagnostic work-up, surveillance of potential complications, and evaluation of therapeutic response.

Aged↗

PubMedDate not supplied

Gastrointestinal stromal tumors: radiologic features with pathologic correlation.

Gastrointestinal stromal tumors (GISTs) are unique neoplasms that occur throughout the gastrointestinal tract, mesentery, omentum, and retroperitoneum. They are the most common mesenchymal neoplasm of the gastrointestinal tract and are defined by their expression of KIT (CD117), a tyrosine kinase growth factor receptor. The expression of KIT is important to distinguish GISTs from other mesenchymal neoplasms such as leiomyomas, leiomyosarcomas, schwannomas, and neurofibromas and to determine the appropriateness of KIT-inhibitor therapy. The series described herein was accumulated over 2 years and includes 64 pathologically proved GISTs (28 gastric, 27 small intestinal, six anorectal, one colonic, one esophageal, and one from the small bowel mesentery). Radiologic features of GISTs vary depending on tumor size and organ of origin. Since most GISTs arise within the muscularis propria of the stomach or intestinal wall, they most commonly have an exophytic growth pattern and manifest as dominant masses outside the organ of origin. Dominant intramural and intraluminal masses are less common radiologic manifestations. GISTs occurring in the gastrointestinal tract and mesentery characteristically have hemorrhage, necrosis, or cyst formation that appears as focal areas of low attenuation on computed tomographic images. Although the radiologic features of GISTs are often distinct from those of epithelial tumors, criteria to separate GISTs radiologically from other nonepithelial tumors have not yet been fully developed.

Diagnosis, Differential↗

PubMedDate not supplied

Primary neoplasms of the appendix: radiologic spectrum of disease with pathologic correlation.

Although uncommon, primary appendiceal neoplasms often result in clinical symptoms that may lead to abdominal imaging. Acute appendicitis from luminal obstruction is the most common manifestation for most tumor types. Other manifestations include intussusception, a palpable mass, gastrointestinal bleeding, increasing abdominal girth (from pseudomyxoma peritonei), and secondary genitourinary complications. Asymptomatic appendiceal neoplasms may be discovered incidentally. Mucoceles from either benign or malignant mucinous neoplasms represent the majority of appendiceal tumors detected at imaging but are the least likely to manifest as appendicitis. Pseudomyxoma peritonei is a common manifestation of mucinous adenocarcinoma. Colonic-type (nonmucinous) adenocarcinoma of the appendix is much less common than mucinous tumors and typically manifests as a focal mass without mucocele formation. Carcinoid tumor is the most common appendiceal neoplasm but is less often detected radiologically because it is typically small and relatively asymptomatic. Goblet cell carcinoid tumor and non-Hodgkin lymphoma of the appendix are rare and usually infiltrate the entire appendix. Cross-sectional imaging, particularly computed tomography (CT), is effective in the evaluation of these neoplasms. CT appears to be the modality of choice whenever an appendiceal mass is suspected. CT will help rule out or confirm an appendiceal tumor and may suggest a more specific diagnosis.

Appendiceal Neoplasms↗

PubMedDate not supplied

From the archives of the AFIP. Meckel diverticulum: radiologic features with pathologic Correlation.

Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract, occurring in 2%-3% of the population. It results from improper closure and absorption of the omphalomesenteric duct. Meckel diverticulum is the most common end result of the spectrum of omphalomesenteric duct anomalies, which also include umbilicoileal fistula, umbilical sinus, umbilical cyst, and a fibrous cord connecting the ileum to the umbilicus. The formation of Meckel diverticulum occurs with equal frequency in both sexes, but symptoms from complications are more common in male patients. Sixty percent of patients come to medical attention before 10 years of age, with the remainder of cases manifesting in adolescence and adulthood. Heterotopic gastric and pancreatic mucosa are frequently found histologically within the diverticula of symptomatic patients. The most common complications are hemorrhage from peptic ulceration, small intestinal obstruction, and diverticulitis. Although the clinical, pathologic, and radiologic features of the complications of Meckel diverticulum are well known, the diagnosis of Meckel diverticulum is difficult to establish preoperatively.

Adolescent↗

PubMedDate not supplied

From the archives of the AFIP: primary vascular neoplasms of the spleen: radiologic-pathologic correlation.

Primary vascular neoplasms of the spleen constitute the majority of nonhematolymphoid splenic tumors. The benign primary vascular tumors include hemangioma, hamartoma, and lymphangioma, whereas those of variable or uncertain biologic behavior include littoral cell angioma, hemangioendothelioma, and hemangiopericytoma. The primary malignant vascular neoplasm of the spleen is angiosarcoma. Peliosis is a rare lesion of unknown cause that is usually found incidentally in asymptomatic patients but may be associated with hematologic or metastatic disease. Although these vascular neoplasms of the spleen are uncommon, their importance lies in that they must be differentiated from the more common neoplastic disorders of the spleen, such as lymphoma and metastasis. The most common echogenic solid or complex cystic mass in an asymptomatic patient is splenic hemangioma. However, the imaging appearance of splenic hemangiomas may be complex, and differentiation of these lesions from malignant disease may not be possible. The diagnosis of splenic hamartoma may be suggested when findings of increased blood flow on color Doppler images are seen in association with a homogeneous solid echogenic mass. A large subcapsular solitary cystic abnormality discovered incidentally in a child in association with internal septations and tiny mural nodules favors the diagnosis of lymphangioma. Any invasion of the surrounding splenic parenchyma by a splenic lesion should indicate a more aggressive or malignant process. Evaluation of a focal splenic abnormality identified on sonograms should be followed up with computed tomography or magnetic resonance imaging with and without contrast material enhancement. Splenectomy may be required for definitive evaluation of a splenic mass with atypical features.

Adult↗

PubMedDate not supplied

From the archives of the AFIP: abdominal neoplasms in patients with neurofibromatosis type 1: radiologic-pathologic correlation.

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders. NF1 is a complex disease resulting from a spectrum of mutations that may occur at many locations along the large, complex NF1 gene, which is located on chromosome 17. Mutations of the NF1 gene lead to abnormal tumor suppression. Consequently, patients with NF1 have an increased prevalence of benign and malignant neoplasms throughout the body. There are five categories of NF1 tumors that occur in the abdomen: neurogenic, neuroendocrine, nonneurogenic gastrointestinal mesenchymal, embryonal, and miscellaneous. Many of these tumors are age related, occur at specific anatomic locations, and have unique imaging features. Notably, many patients have a variety of organs affected because there is a high prevalence of multiple tumors occurring in the same patient. Neurofibromas are the most common benign neoplasms and may occur in the retroperitoneum or visceral organs. Malignant peripheral nerve sheath tumor is an aggressive malignancy that is the most common malignant tumor of the abdomen in patients with NF1. Interpreting abdominal imaging studies in patients with NF1 can be challenging because of the wide spectrum and diverse nature of tumors that occur in this disease.

Abdominal Neoplasms↗

PubMedDate not supplied

From the archives of the AFIP: benign fibrous tumors and tumorlike lesions of the mesentery: radiologic-pathologic correlation.

Mesenteric fibromatosis, sclerosing mesenteritis, inflammatory pseudotumor, and extrapleural solitary fibrous tumor constitute a loosely associated group of benign fibrous tumors and tumorlike lesions of the mesentery. These lesions are linked histologically by the presence of fibroblasts or fibrosis and anatomically by their location within the mesentery. Although rare, and distinctly different in pathogenesis and biologic behavior, these fibrous lesions have pathologic and radiologic features that overlap with one another and with more common neoplastic and nonneoplastic lesions of the mesentery. Mesenteric fibromatosis is a locally aggressive, benign proliferative process that may occur sporadically or in association with familial adenomatous polyposis. It most frequently manifests as a focal mesenteric mass and may simulate lymphoma, metastatic disease, or a soft-tissue sarcoma. Sclerosing mesenteritis is a rare idiopathic disorder that most commonly produces a stellate mass within the mesentery and should be differentiated from metastatic disease, specifically metastatic carcinoid, because it frequently responds to conservative or medical management. Inflammatory pseudotumor (inflammatory myofibroblastic tumor) is a benign, chronic inflammatory disorder of unknown cause that manifests as a solid mesenteric mass, indistinguishable from malignancy. Extrapleural solitary fibrous tumor is a tumor of submesothelial origin that is identical to the solitary fibrous tumor of the pleura. When located in the mesentery or peritoneal cavity, extrapleural solitary fibrous tumor has an imaging pattern that must be differentiated from metastatic disease, soft-tissue sarcomas, and other benign and malignant neoplasms of the mesentery and peritoneum. Knowledge of this group of benign fibrous tumors and tumorlike lesions of the mesentery is important in the preoperative evaluation of a mesenteric mass.

Adult↗