Prolapsed Uterine Smooth Muscle Tumor of Uncertain Malignant Potential: A Case Report and Review of Radiologic Findings.

INTRODUCTION: Uterine smooth muscle tumor of uncertain malignant potential (STUMP) is a rare tumor that arises in the myometrium of the uterus. It is regarded as an intermediate malignant tumor according to the recent World Health Organization classification. Few studies have reported the radiologic findings of STUMP, and the differentiation of STUMP from leiomyoma remains controversial. CASE DESCRIPTION: A 42-year-old nulliparous female presented at our institution with massive vaginal bleeding. Radiological studies, including ultrasonography, computed tomography (CT), and magnetic resonance imaging, revealed an oval-shaped mass with well-defined margins in the uterus protruding into the vagina. The patient underwent a total abdominal hysterectomy, and the final pathology was confirmed as STUMP. CONCLUSION: Distinguishing STUMP from leiomyomas based solely on radiological findings can be challenging. However, if the uterine mass appears as a single mass lacking acoustic shadowing on ultrasound and demonstrates diffusion restriction with high T2 signal intensity on magnetic resonance imaging, consideration of STUMP may be necessary for proper patient management, given the poor prognosis associated with this tumor.

Huge Primary Clear Cell Hepatocellular Carcinoma: a Case Report and Review of Radiologic Findings.

INTRODUCTION: Clear cell hepatocellular carcinoma (HCC) is a rare subtype of HCC. Histologically, clear cell HCC is characterized by the cytoplasmic accumulation of glycogen with a clear cell appearance, constituting > 80% of tumor cells. Radiologically, clear cell HCC demonstrates early enhancement and washout similar to conventional HCC. Occasionally, enhancing capsule and intratumoral fat are accompanied by clear cell HCC. CASE DESCRIPTION: A 57-year-old male presented to our hospital with right upper quadrant abdominal pain. Ultrasonography, computed tomography, and magnetic resonance imaging revealed a large mass with a well-defined margin in the right hemiliver. The patient underwent a right hemihepatectomy, and the final histopathology revealed clear cell-type HCC. CONCLUSION: Distinguishing clear cell types from other types of HCC solely based on radiological findings is challenging. If hepatic tumors exhibit encapsulated margins, enhancing rims, intratumoral fat, and arterial phase hyperenhancement/washout pattern despite their large size, consideration of clear cell subtypes in the differential diagnosis list will aid patient management, implying better prognosis than not-otherwise-specified HCC.

Value of threshold growth as a major diagnostic feature of hepatocellular carcinoma in LI-RADS.

BACKGROUND & AIMS: The Liver Reporting and Data System (LI-RADS) version 2018 simplified the definition of threshold growth to '≥50% size increase in a mass in ≤6 months'. However, the diagnostic value of threshold growth for hepatocellular carcinoma (HCC) remained unclear. We evaluated the value of threshold growth, as defined by LI-RADS v2018, in diagnosing HCCs. METHODS: Patients who underwent preoperative gadoxetate disodium-enhanced MRI because of the presence of LI-RADS category 2, 3, or 4 rather than category 5 on prior CT/MRI between January 2017 and December 2020 were retrospectively evaluated. Pathologic or clinical diagnoses were used as reference standards. Imaging features were evaluated by three readers according to LI-RADS v2018. The frequency and diagnostic odds ratio of threshold growth were calculated. The diagnostic performance of LI-RADS category 5 was separately evaluated when threshold growth was and was not considered a major feature, and results were compared using generalized estimation equations. Subgroups of patients who underwent CT/MRI during the previous 3-6 months were analyzed. RESULTS: Analysis of 340 observations in 243 patients found that the frequency of threshold growth was 18.8% and it gradually increased over time. Threshold growth was significantly associated with HCC (diagnostic odds ratio 5.2; 95% CI 2.1-12.7; p <0.001). Use of threshold growth as a major feature significantly increased sensitivity in both the overall (66.4% vs. 57.3%, p <0.001) and subgroup (73.4% vs. 58.2%, p <0.001) cohorts, but had no effect on specificity in either the overall (97.5% vs. 98.3%, p = 0.319) or subgroup (95.9% vs. 98.0%, p = 0.323) cohorts. CONCLUSION: The revised threshold growth of LI-RADS v2018 was significantly associated with HCC. Use of threshold growth as a major diagnostic feature of HCC can improve the sensitivity of LI-RADS v2018. IMPACT AND IMPLICATIONS: We found that the revised threshold growth in the Liver Imaging Reporting and Data System version 2018 (LI-RADS v2018) was a significant predictor of hepatocellular carcinoma (HCC). The use of threshold growth as a major imaging feature of HCC significantly increased the sensitivity of LI-RADS v2018, especially small HCCs (≤3.0 cm), compared with its non-use. Because these small HCCs are eligible for curative treatments, the additional detection of small HCCs is clinically meaningful.

Simplified LI-RADS for Hepatocellular Carcinoma Diagnosis at Gadoxetic Acid-enhanced MRI.

Background Although various modifications to the Liver Imaging Reporting and Data System (LI-RADS) at gadoxetic acid-enhanced MRI have been suggested, LI-RADS shows suboptimal sensitivity for hepatocellular carcinoma (HCC) and is perceived to be too complex. Purpose To evaluate clinical usefulness of a simplified LI-RADS for diagnosing HCCs of 30 mm or smaller at gadoxetic acid-enhanced MRI. Materials and Methods Patients who underwent gadoxetic acid-enhanced MRI examination and subsequent resection, transplantation, or biopsy for focal solid nodules of 30 mm or smaller between January 2019 and December 2020 at a single tertiary referral institution were retrospectively analyzed. Two strategies for simplified LI-RADS using one size criterion (≥10 mm) were evaluated (strategy A, using classifications for nodules of 10-19 mm for nodules both 10-19 mm and ≥20 mm; strategy B, using classifications for nodules ≥20 mm for nodules both 10-19 mm and ≥20 mm). Multivariable analysis was performed to determine significant ancillary features for HCC. Generalized estimating equations were used to compare diagnostic performance for LR-5 (definite HCC) between LI-RADS version 2018 and simplified LI-RADS. The time required for LI-RADS category assignment was compared between the two systems with use of a paired t test. Results A total of 645 nodules from 510 patients (mean age ± SD, 60 years ± 10; 393 men) were evaluated. Compared with strategy A, strategy B had a higher sensitivity of 74% (347 of 470 nodules [95% CI: 70, 78]) vs 73% (342 of 470 nodules [95% CI: 69, 77]) (P = .02) with the same specificity of 96% (168 of 175 nodules [95% CI: 92, 98]) vs 96% (168 of 175 nodules [95% CI: 92, 98]) (P > .99). In strategy B, transitional phase hypointensity was an independent ancillary feature for HCC (P = .04) in LR-4 of at least 10 mm with arterial phase hyperenhancement and no other major features. In all 645 nodules, simplified LI-RADS with use of both strategy B and transitional phase hypointensity had a higher sensitivity of 82% (387 of 470 nodules [95% CI: 79, 86]) vs 73% (343 of 470 nodules [95% CI: 69, 77]) (P < .001) than LI-RADS version 2018, without lower specificity (94%, 165 of 175 nodules [95% CI: 90, 97] vs 96%, 168 of 175 nodules [95% CI: 92, 98], P = .08). Compared with LI-RADS version 2018, simplified LI-RADS reduced the time for LI-RADS category assignment (44 seconds ± 23 vs 74 seconds ± 22, P < .001). Conclusion A simplified Liver Imaging Reporting and Data System was found to be clinically useful for diagnosing hepatocellular carcinomas of 30 mm or smaller at gadoxetic acid-enhanced MRI. © RSNA, 2022 Online supplemental material is available for this article.

Uterine Angiolipoleiomyoma with US, CT, and MRI Findings: A Case Report.

INTRODUCTION: Angiolipoleiomyoma (ALLM) is a rare hamartomatous tumor of mesenchymal origin composed of smooth muscle, mature adipose tissue, and blood vessels in various proportions. Because of its histologic similarity to renal Angiomyolipoma (AML), it is also called uterine angiomyolipoma. Preoperative diagnosis of uterine ALLM is very challenging due to its uncommon incidence and absence of established characteristic imaging findings. CASE PRESENTATION: A 50-year-old multiparous female patient visited our institution for gynecologic screening. Transvaginal Sonography (TVS), Abdominopelvic Computed Tomography (CT), and pelvic Magnetic Resonance Imaging (MRI) revealed large well-defined masses involving the posterior uterine wall with rectal indentation. The patient underwent a total abdominal hysterectomy for this tumor and the histopathological diagnosis was uterine ALLM. CONCLUSION: This report would contribute to understanding and establishing the radiologic findings of the uterine ALLM. Considering the benign characteristics and favorable prognosis of this rare tumor, familiarity with its imaging findings by radiologists will guide clinicians in better patient management and prevention of unnecessary radical surgery.

Gangliocytic Paraganglioma of the Gastrointestinal Tract: A Case Report of Cecal Origin.

INTRODUCTION: Gangliocytic paraganglioma is an extremely rare tumor that is composed of epithelioid, ganglion, and spindle cells. It has a predilection site in the duodenum, especially the periampullary region. The clinical course is usually benign, but a few cases of metastasis to lymph nodes or distant sites have been noted. Several case reports or small series reviews of gangliocytic paraganglioma have been published, but so far, cecal gangliocytic paraganglioma has not been described. CASE DESCRIPTION: A 61-year-old man underwent an abdominal Computed Tomography (CT) scan for known GB stones, which revealed an incidental cecal mass. The patient underwent wedge resection of the cecum for diagnostic and therapeutic purposes. Histopathological examination of the cecal mass identified a gangliocytic paraganglioma. There was no evidence of metastasis in the dissected regional lymph nodes. No additional treatment, such as adjuvant chemotherapy or radiotherapy, was administered, and the patient underwent regular follow-up without any complications. CONCLUSION: The most common radiologic finding in gangliocytic paraganglioma is a circumscribed, enhancing subepithelial mass. Herein, we report an uncommon case of cecal-origin gangliocytic paraganglioma. With knowledge of the radiologic and histologic characteristics of gangliocytic paraganglioma, appropriate management can be provided without unnecessary radical resection.

Embolization of Inferior Pancreaticoduodenal Artery Aneurysm with Celiac Stenosis or Occlusion: A Report of Three Cases and a Review of Literature.

True pancreaticoduodenal artery aneurysms are relatively rare, approximately 50% of which are associated with stenosis or occlusion of the celiac axis. It is imperative to treat the condition immediately after diagnosis, considering that its rupture has a mortality rate of approximately 50%. The current most commonly used method to treat pancreaticoduodenal artery aneurysms is transcatheter arterial embolization. Here, we report three cases of embolization of inferior pancreaticoduodenal artery aneurysm with celiac stenosis or occlusion along with a literature review.