Najla Fasih

Leiomyomas beyond the Uterus: Unusual Locations, Rare Manifestations

Uterine leiomyomas affect 20%-30% of women older than 35 years. Extrauterine leiomyomas are rarer, and they present a greater diagnostic challenge: These histologically benign tumors, which originate from smooth muscle cells, usually arise in the genitourinary tract (in the vulva, ovaries, urethra, and urinary bladder) but may arise in nearly any anatomic site. In addition, unusual growth patterns may be seen, including benign metastasizing leiomyoma, disseminated peritoneal leiomyomatosis, intravenous leiomyomatosis, parasitic leiomyoma, and retroperitoneal growth. In the presence of such a pattern, a synchronous uterine leiomyoma or a previous hysterectomy for removal of a primary uterine tumor may be indicative of the diagnosis. However, some extrauterine leiomyomas may mimic malignancies, and serious diagnostic errors may result. The most useful modalities for detecting extrauterine leiomyomas are ultrasonography, computed tomography, and magnetic resonance (MR) imaging. The superb contrast resolution and multiplanar capabilities of MR imaging make it particularly valuable for characterizing these tumors, which usually show low signal intensity similar to that of smooth muscle on T2-weighted images. The radiologists recognition of this and other characteristic features may help steer the clinician toward timely, appropriate management and away from unnecessary, potentially harmful treatment.

A clinical and radiologic review of uncommon types and causes of pancreatitis.

Acute pancreatitis is one of the most common conditions for which emergent imaging is indicated. Alcohol consumption and cholelithiasis are the most common causes of acute pancreatitis in adults, whereas the majority of cases in children are idiopathic or secondary to trauma. A wide variety of structural and biochemical abnormalities may also cause pancreatitis. Although in some cases it is difficult to identify the specific cause of the disease radiologically, certain uncommon types of acute or chronic pancreatitis may have unique imaging features that can help the radiologist make an accurate diagnosis. These unusual types include autoimmune pancreatitis, groove pancreatitis, tropical pancreatitis, hereditary pancreatitis, and pancreatitis in ectopic or heterotopic pancreatic tissue. Pancreatitis may occasionally be seen in association with cystic fibrosis or pancreas divisum, or secondary to worm infestation of the pancreaticobiliary tree (eg, by Ascaris lumbricoides). In addition, primary pancreatic and duodenal masses may occasionally manifest as acute or recurrent acute pancreatitis. Knowledge of the classic imaging findings of these entities allows prompt recognition of the relevant pathologic condition, thereby preventing misdiagnosis and subsequent inappropriate or delayed management.

Histologic, Molecular, and Cytogenetic Features of Ovarian Cancers: Implications for Diagnosis and Treatment

Ovarian epithelial carcinoma (OEC), the most common ovarian malignancy, is a heterogeneous disease with several histologic subtypes that show characteristic cytogenetic features, molecular signatures, oncologic signaling pathways, and clinical-biologic behavior. Recent advances in histopathology and cytogenetics have provided insights into pathophysiologic features and natural history of OECs. Several studies have shown that high- or low-grade serous, endometrioid, and clear cell carcinomas are characterized by mutations involving the TP53, K-ras/BRAF, CTNNB1, and PIK3CA genes, respectively. High-grade serous carcinomas, the most common subtype, often manifest with early transcoelomic spread of disease beyond the ovaries, whereas low-grade serous and mucinous carcinomas commonly manifest with early-stage disease, with a resultant excellent prognosis. On the basis of pathogenetic mechanisms, recent findings suggest a dualistic model of ovarian carcinogenesis consisting of types I and II. Type I (low-grade serous, mucinous, and endometrioid) cancers commonly arise from well-described, genetically stable precursor lesions (usually borderline tumors); manifest as large adnexal masses with early-stage disease; and have a relatively indolent clinical course, with an overall good prognosis. In contrast, type II carcinomas (high-grade serous, endometrioid, mixed, and undifferentiated variants) originate de novo from the adnexal epithelia, often demonstrate chromosomal instability, and have aggressive biologic behavior. Better knowledge of hereditary ovarian cancer syndromes and associated cytogenetic abnormalities has led to increased interest in novel biomarkers and molecular therapeutics. Genetic changes, pathologic features, imaging findings, and natural histories of a variety of histologic subtypes of OEC are discussed in this article.

Benign Biliary Strictures: A Current Comprehensive Clinical and Imaging Review

OBJECTIVE There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities. CONCLUSION Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.

Clinical syndromes associated with ovarian neoplasms: A comprehensive review

Functional ovarian neoplasms have unique clinical manifestations related to hormone overproduction and may give rise to a broad spectrum of clinical syndromes. Sex cord-stromal tumors, the most common functional ovarian neoplasms, are associated with either hyperestrogenism (as in granulosa cell tumor and thecoma) or hyperandrogenism (as in Sertoli-Leydig cell tumor and Leydig cell tumor). Other, less common ovarian neoplasms that may have endocrine or nonendocrine syndromic manifestations include germ cell tumors associated with the excessive production of human chorionic gonadotropin (eg, choriocarcinoma, dysgerminoma), monodermal teratomas (eg, carcinoid tumor, struma ovarii) associated with carcinoid syndrome and hyperthyroidism, and primary epithelial ovarian cancers associated with paraneoplastic syndromes. The application of diagnostic algorithms based on patient demographic information, clinical manifestations, laboratory findings, and cross-sectional imaging features may help identify ovarian neoplasms in complex clinical settings.

Current concepts in the imaging of uterine sarcoma

Recent advances in genetics and pathology have improved our understanding of diagnosis and staging of uterine sarcomas. The major types of uterine sarcomas include leiomyosarcoma, low-grade endometrial stromal sarcoma, undifferentiated endometrial sarcoma, adenosarcoma and carcinosarcoma. The distinctive biological behavior and poor overall survival of uterine sarcoma create challenges in the management of these tumors. We herein present a comprehensive review of taxonomy, epidemiology, pathology, imaging findings and natural history of a wide spectrum of uterine sarcomas.

Unusual imaging appearances of endometriosis

OBJECTIVE Endometriosis is defined as tissue resembling the endometrium occurring outside the uterus. The purpose of this article is to familiarize the radiologist with the wide spectrum of pelvic endometriosis and to review the distinctive imaging findings. Infrequent manifestations of endometriosis, including malignant degeneration, scar endometriosis, association with ascites, and invasive endometriosis, are described. CONCLUSION The manifestations of endometriosis commonly present a challenge to the gynecologist and radiologist. Familiarity with its varied presentations may allow accurate diagnosis.

Uncommon Primary Pelvic Retroperitoneal Masses in Adults: A Pattern-based Imaging Approach

There is a broad spectrum of primary pelvic retroperitoneal masses in adults that demonstrate characteristic epidemiologic and histopathologic features and natural histories. These masses may be classified into five distinct subgroups using a pattern-based approach that takes anatomic distribution and certain imaging characteristics into account, allowing greater accuracy in their detection and characterization and helping to optimize patient management. The five groups are cystic (serous and mucinous epithelial neoplasms, pelvic lymphangioma, tailgut cyst, ancient schwannoma), vascular or hypervascular (solitary fibrous tumor, paraganglioma, pelvic arteriovenous malformation, Klippel-Trénaunay-Weber syndrome, extraintestinal GIST [gastrointestinal stromal tumor]), fat-containing (lipoma, liposarcoma, myelolipoma, presacral teratoma), calcified (calcified lymphocele, calcified rejected transplant kidney, rare sarcomas), and myxoid (schwannoma, plexiform neurofibroma, myxoma).Cross-sectional imaging modalities help differentiate the more common gynecologic neoplasms from more unusual masses. In particular, the tissue-specific multiplanar capability of high-resolution magnetic resonance imaging permits better tumor localization and internal characterization, thereby serving as a road map for surgery.

Imaging of Acute Abdomen in Pregnancy

The approach to imaging in pregnancy is unique, as it is essential to minimize radiation exposure to the fetus. Ultrasonography and magnetic resonance imaging are the chief modalities for evaluation of the pregnant patient with abdominal pain. Use of computed tomography should not be delayed when there is a need for early diagnosis. This article discusses test selection and underlying reasoning, with a description of common imaging features of different causes of acute abdominal pain in pregnancy. Also discussed are current evidence-based recommendations for the use of iodinated and gadolinium-based contrast agents and the importance of patient counseling.

Ultrasound, Computed Tomography, and Magnetic Resonance Imaging of Ovarian Vein Thrombosis in Obstetrical and Nonobstetrical Patients

Ovarian vein thrombosis is an uncommon clinical entity, most familiar to radiologists as a source of postpartum sepsis, which, if unrecognized and left untreated, has the potential for septic shock, pulmonary thromboembolism, and death. Ovarian vein thrombosis also occurs with other common inflammatory and malignant conditions in the nonobstetrical patient. This article reviews the pathophysiology, predisposing conditions, clinical findings, imaging features on ultrasonography, computed tomography, and magnetic resonance imaging of acute and chronic ovarian vein thrombosis and its appropriate clinical management.