MRI findings of epithelial–myoepithelial carcinoma of the parotid gland with radiologic–pathologic correlation

Purpose This study aimed to describe the MRI findings of epithelial-myoepithelial carcinoma (EMC) of the parotid gland. Materials and methods Seven patients (four males and three females) aged 40–86 years (mean age, 64 years) with histologically proven EMC of the parotid gland who underwent surgical resection after preoperative MRI were enrolled. MRI images were retrospectively reviewed and contrasted with pathological findings. Results Five patients (71%) had predominantly solid lesions, and two (29%) had predominantly cystic lesions. All seven lesions had well-demarcated margins and capsules without the invasion of adjacent structures. The capsules were incomplete in five lesions (71%) and complete in two (29%). Four lesions (57%) exhibited a multinodular structure with internal septa. Cystic components were observed in three lesions (43%). On T1-weighted images, the solid components were frequently homogeneous (5/7, 71%), and demonstrated isointensity in five lesions (71%) and hypointensity in two (29%) relative to the spinal cord. On T2-weighted images, the solid components were usually heterogeneous (6/7, 86%), and demonstrated hyperintensity in five lesions (71%) and isointensity in two (29%) relative to the spinal cord. The mean apparent diffusion coefficient value of the solid components was 0.967 × 10−3 mm2/s. Conclusion Parotid gland EMCs usually appeared as predominantly solid lesions with well-demarcated margins and capsules. A multinodular structure with internal septa was characteristics of EMCs.

A Comparative Assessment of MR BI-RADS 4 Breast Lesions With Kaiser Score and Apparent Diffusion Coefficient Value

ObjectivesTo investigate the diagnostic performance of the Kaiser score and apparent diffusion coefficient (ADC) to differentiate Breast Imaging Reporting and Data System (BI-RADS) Category 4 lesions at dynamic contrast-enhanced (DCE) MRI.MethodsThis was a single-institution retrospective study of patients who underwent breast MRI from March 2020 to June 2021. All image data were acquired with a 3-T MRI system. Kaiser score of each lesion was assigned by an experienced breast radiologist. Kaiser score+ was determined by combining ADC and Kaiser score. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of Kaiser score+, Kaiser score, and ADC. The area under the curve (AUC) values were calculated and compared by using the Delong test. The differences in sensitivity and specificity between different indicators were determined by the McNemar test.ResultsThe study involved 243 women (mean age, 43.1 years; age range, 18–67 years) with 268 MR BI-RADS 4 lesions. Overall diagnostic performance for Kaiser score (AUC, 0.902) was significantly higher than for ADC (AUC, 0.81; p = 0.004). There were no significant differences in AUCs between Kaiser score and Kaiser score+ (p = 0.134). The Kaiser score was superior to ADC in avoiding unnecessary biopsies (p < 0.001). Compared with the Kaiser score alone, the specificity of Kaiser score+ increased by 7.82%, however, at the price of a lower sensitivity.ConclusionFor MR BI-RADS category 4 breast lesions, the Kaiser score was superior to ADC mapping regarding the potential to avoid unnecessary biopsies. However, the combination of both indicators did not significantly contribute to breast cancer diagnosis of this subgroup.

Differentiation of uterine low-grade endometrial stromal sarcoma from rare leiomyoma variants by magnetic resonance imaging

The purpose of this study is to evaluate utility of MRI in differentiation of uterine low-grade endometrial stromal sarcoma (LGESS) from rare leiomyoma variants. This multi-center retrospective study included consecutive 25 patients with uterine LGESS and 42 patients with rare leiomyoma variants who had pretreatment MRI. Two radiologists (R1/R2) independently evaluated MRI features, which were analyzed statistically using Fisher’s exact test or Student's t-test. Subsequently, using a five-point Likert scale, the two radiologists evaluated the diagnostic performance of a pre-defined MRI system using features reported as characteristics of LGESS in previous case series: uterine tumor with high signal intensity (SI) on diffusion-weighted images and with either worm-like nodular extension, intra-tumoral low SI bands, or low SI rim on T2-weighted images. Area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of the two readers’ Likert scales were analyzed. Intra-tumoral low SI bands (p < 0.001), cystic/necrotic change (p ≤ 0.02), absence of speckled appearance (p < 0.001) on T2-weighted images, and a low apparent diffusion coefficient value (p ≤ 0.02) were significantly associated with LGESS. The pre-defined MRI system showed very good diagnostic performance: AUC 0.86/0.89, sensitivity 0.95/0.95, and specificity 0.67/0.69 for R1/R2. MRI can be useful to differentiate uterine LGESS from rare leiomyoma variants.

Primary pharyngeal synovial sarcoma in a pediatric patient: A case report

BackgroundSynovial sarcoma is a rare malignant tumor that typically originates from the soft tissue of the extremities. The occurrence of primary pharyngeal synovial sarcoma (PPSS) is even rarer, and few studies have reported its radiological features. Here, we report a case of pediatric PPSS and describe the conventional and advanced magnetic resonance imaging (MRI) findings with pathologic correlation.Case presentationAn 11-year-old girl presented to the otolaryngologic clinic with dysphagia. Laryngoscopy revealed a large mass in the oropharynx. MRI revealed a well-defined soft tissue mass with a maximal diameter of approximately 5 cm originating from the submucosal space of the oropharynx. The mass was primarily solid and showed homogeneous contrast-enhancement. The mass was hypointense on T1-weighted images and hyperintense on T2-weighted images. The mass showed a homogeneously low apparent diffusion coefficient value on diffusion-weighted imaging, which indicated high tumor cellularity. Dynamic contrast-enhanced MRI revealed a hypovascular tumor with low values of the volume transfer constant between the extracellular extravascular space and blood plasma and blood plasma volume per unit tissue volume. Amide proton transfer-weighted MRI revealed a relatively high amide proton transfer signal in the tumor, indicating a high protein/peptide component. The patient underwent surgical resection of the tumor, and the diagnosis of biphasic synovial sarcoma was confirmed on postoperative pathological examination. The patient was started on chemotherapy with vincristine, ifosfamide, doxorubicin, and etoposide, and the patient is still under follow-up.ConclusionSynovial sarcoma should be considered in the differential diagnosis of pediatric oropharyngeal submucosal tumors. Multimodal MRI may aid diagnosis, although the final diagnosis should be based on the postoperative pathological examination findings.

In prostatic transition zone lesions (PI-RADS v2.1): which subgroup should be biopsied?

Background The study aimed to compare the diagnostic performance of T2-weighted imaging (T2WI) score 3 transition zone (TZ) lesions between Prostate Imaging and Reporting Data System (PI-RADS) v2.1 and modified PI-RADS v2.1-B. Results Among TZ lesions (n = 78), 47 (60.0%) had T2WI score of 3, and 16 of the 47 (34.0%) were malignant. The rate of malignancy was 8.8% in PI-RADS category 3A, 100% in PI-RADS category 3B, and 100% in PI-RADS category 4. The apparent diffusion coefficient value of PI-RADS category 3B (0.934 ± 0.158 × 10−3 mm2/s) showed significant difference with that of PI-RADS category 3A (1.098 ± 0.146 × 10−3 mm2/s) but none with PI-RADS category 4 (0.821 ± 0.091 × 10−3 mm2/s). There was no significant difference in the sensitivity and negative predictive value of PI-RADS v2.1 and PI-RADS v2.1-B. Specificity and positive predictive value of modified PI-RADS v2.1-B were much higher than those of PI-RADS v2.1 for both readers (p < .001). The area under the receiver operating characteristic curve tended to be higher with PI-RADS v2.1-B than with PI-RADS v2.1. Conclusion Biopsy for PI-RADS 3B lesion is necessary due to its superior malignancy potential than that of PI-RADS 3A lesion.

Nomograms of Combining Apparent Diffusion Coefficient Value and Radiomics for Preoperative Risk Evaluation in Endometrial Carcinoma

ObjectivesTo evaluate the value of nomogram models combining apparent diffusion coefficient (ADC) value and radiomic features on magnetic resonance imaging (MRI) in predicting the type, grade, deep myometrial invasion (DMI), lymphovascular space invasion (LVSI), and lymph node metastasis (LNM) of endometrial carcinoma (EC) preoperatively.MethodsThis study included 210 EC patients. ADC value was calculated, and radiomic features were measured on T2-weighted images. The univariate and multivariate logistic regressions and cross-validations were performed to reduce valueless features, then radiomics signatures were developed. Nomogram models using ADC combined with radiomic features were developed in the training cohort. The receiver operating characteristic (ROC) curve was performed to estimate the diagnostic efficiency of nomogram models by the area under the curve (AUC) in the training and validation cohorts.ResultsThe ADC value was significantly different between each subgroup. Radiomic features were ultimately limited to four features for type, six features for grade, six features for DMI, four features for LVSI, and eight features for LNM for the nomogram models. The AUC of the nomogram model combining ADC value and radiomic features in the training and validation cohorts was 0.851 and 0.867 for type, 0.959 and 0.880 for grade, 0.839 and 0.766 for DMI, 0.816 and 0.746 for LVSI, and 0.910 and 0.897 for LNM.ConclusionsThe nomogram models of ADC value combined with radiomic features were associated with the type, grade, DMI, LVSI, and LNM of EC, and provide an effective, non-invasive method to evaluate preoperative risk stratification for EC.

Low diffusion level within a fibroadenoma as the sole sign of ductal carcinoma in situ: A case report

We present a case of ductal carcinoma in situ within a fibroadenoma. Breast cancer arising within fibroadenoma incidence ranges from 0.125% to 0.02%, and ductal carcinoma in situ is not the most frequent malignancy that can be found within a fibroadenoma. Dynamic contrast-enhanced magnetic resonance imaging showed an oval mass with circumscribed margins and dark internal septations, suspicious for fibroadenoma. According to European Society of Breast Radiology diffusion-weighted imaging consensus, mean apparent diffusion coefficient value obtained by drawing a small region of interest on the lesion apparent diffusion coefficient map showed a low diffusion level. Therefore, ductal carcinoma in situ within a fibroadenoma was diagnosed at final pathology after surgical excision.

Gastrointestinal Stromal Tumor of the Small Bowel Complicated by Torsion: A Case Report

Background: Gastrointestinal stromal tumor (GIST) is a mesenchymal tumor originating in the wall of the gastrointestinal tract, and 20-30% of these tumors originate from the small intestine. The clinical manifestations of GIST of the small intestine generally include a palpable mass, distention, and abdominal pain and sometimes include acute abdomen due to ileus, bleeding, perforation, and intussusception at onset. Here, we describe a rare case of a pedunculated GIST of the small intestine complicated by torsion.Case presentation: A 69-year-old woman was referred for lower abdominal pain. Abdominal contrast-enhanced computed tomography showed a 73×62×57-mm tumor in the pelvic cavity with an enhanced margin and reduced contrast effect inside of it. T2-weighted magnetic resonance imaging showed a hyperintense, demarcated, lobulated tumor. The diffusion-weighted image showed hyperintensity, and the apparent diffusion coefficient value revealed diffusion restriction, indicating malignancy. T1-weighted images showed a low intensity tumor; contrast-enhanced images showed hypointensity inside of the tumor and slight hyperintensity around its edges. It was presumed that the tumor had caused hemorrhagic infarction. Emergency laparotomy was performed, and the pedunculated tumor was found to be twisted 360 degrees clockwise at the pedicle with hemorrhage and necrosis due to torsion. We performed partial resection of the small intestine including the tumor. Histopathology revealed tightly arranged spindle-shaped cells with hemorrhage, congestion, and inflammatory cell infiltration. Immunohistochemical staining showed positivity for CD34, CD117, and DOG1.Conclusions: The present report describes a very rare case in which pedicle torsion of an extra luminal expanding GIST of small intestine, although there were some reports of small intestine volvulus caused by GIST of small intestine as a rare condition. The torsion of pedunculated GIST of small intestine should be recognized as an emergency condition of GIST, and we report that characteristic findings of this condition were acquired with CT and MRI which was possibility useful for the diagnosis.