Placenta accreta (PA) encompasses various types of abnormal placentation in which chorionic villi attach directly to or invade the myometrium. PA is a significant cause of maternal morbidity and mortality and is now the most common reason for emergent postpartum hysterectomy. Its prevalence has risen tenfold in the United States over the past 50 years, primarily due to the increasing percentage of pregnant patients undergoing primary and repeat cesarean sections. Placenta previa and previous cesarean section are the two most important known risk factors for PA. Accurate prenatal identification of affected pregnancies allows optimal obstetric management. Ultrasonography (US) remains the diagnostic standard, and routine US examination at 18-20 weeks gestation affords an ideal opportunity to screen for the disorder. Placental lacunae and abnormal color Doppler imaging patterns are the most helpful US markers for PA. In recent years, there has been increased interest in magnetic resonance (MR) imaging for the evaluation of PA, since it can provide information on depth of invasion and more clearly depict posterior placentas. The most reliable MR imaging findings are uterine bulging, heterogeneous placenta, and placental bands. Focal interruptions in the hypointense myometrial border may also be helpful. PA is a clinical and diagnostic challenge that is being encountered with increasing frequency. Clinicians should be aware of the clinical issues, risk factors, and imaging findings associated with PA to facilitate optimal case management.

Tumors and tumorlike conditions of the anus and perianal region originate from the anal canal and anal margin or result from direct extension of tumors from adjacent organs. The anatomy of the anal canal is complex, and its different histologic characteristics can lead to diverse pathologic conditions. The anal canal extends from the anorectal junction to the anal verge. The World Health Organization classification of anal canal tumors includes (a) anal intraepithelial neoplasia, the precursor of squamous cell carcinoma (SCC), and (b) invasive tumors. Invasive tumors are further classified on the basis of cell type as epithelial tumors (SCC, adenocarcinoma, mucinous adenocarcinoma, small cell carcinoma, and undifferentiated carcinoma), nonepithelial tumors, carcinoid tumors, melanoma, and secondary tumors (direct spread from rectal, cervical, or prostate carcinoma). The anal margin, or perianal skin, lies outside the anal verge and encompasses a radius of 5 cm from the anal verge. Tumors in the anal margin are classified according to the World Health Organization classification of skin tumors. Anal margin tumors include SCC, anal intraepithelial neoplasia, also known as Bowen disease, adenocarcinoma and its precursor Paget disease, basal cell carcinoma, and verrucous carcinoma (Buschke-Löwenstein tumor), which is a rare variant of SCC. Imaging plays an important role in the evaluation, staging, and follow-up of patients with anal and perianal tumors. However, because of the overlap in imaging features among these diverse entities, a definitive diagnosis is best established at histopathologic examination. Nevertheless, familiarity with the pathogenesis, imaging features, and treatment of these tumors can aid radiologic diagnosis and guide appropriate patient treatment. (©)RSNA, 2016.

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Background Adrenal cavernous hemangioma is a rare tumor with only 60 cases previously reported. The aim of this study was to determine the frequency and clinical significance of adrenal cavernous hemangioma at our institution. Methods A retrospective review of consecutive patients undergoing adrenalectomy from 1994 to 2018 was completed to determine the frequency of cavernous hemangioma, characterize the clinical presentation, imaging and pathologic features and review the operative management and outcome. Results Of 144 consecutive patients who underwent adrenalectomy by a single surgeon, 5 (3.5%) had an adrenal cavernous hemangioma. All were incidentally discovered, nonfunctional adrenal masses varying in size from 7 to 12 cm with imaging features that were indeterminate in differentiating a benign adenoma from an adrenal cortical carcinoma. Attenuation values for the adrenal masses on noncontrast computed tomography varied from 28 to 34 Hounsfield units. All adrenal cavernous hemangiomas were large, heterogeneous, complex masses with a variable presence of calcification, hemorrhage, and necrosis. These features, along with tumor enlargement were concerning for adrenal cortical carcinoma. During the operation, there was no local invasion and all adrenal tumors were successfully removed laparoscopically without tumor rupture or bleeding. All patients had an uneventful postoperative course without complications. Conclusion Adrenal cavernous hemangioma is a rare tumor that can grow to a very large size without causing symptoms, making it difficult to differentiate from adrenal cortical carcinoma clinically or radiographically. Despite its large size, adrenal cavernous hemangioma can be safely resected laparoscopically.