Description: The purpose of this study is to investigate the utility of the apparent diffusion coefficient (ADC) in differentiating benign and malignant uterine smooth muscle tumors classified by signal intensity (SI) on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI), and to determine the correlation between ADC and tumor cell density. This retrospective study reviewed 168 lesions in 134 cases with pathologically confirmed uterine smooth muscle tumors, including 6 leiomyosarcomas and 3 smooth muscle tumors of uncertain malignant potential, and preoperative magnetic resonance imaging examinations performed between October 2009 and November 2012. T2WI and DWI were also performed for each subject. Tumors were then classified according to SI on T2WI and DWI relative to myometrial SI. The correlation between ADC and tumor cell density was also determined. In Group 1 (high on both T2WI/DWI), mean ADC was significantly lower for leiomyosarcoma (0.91 × 10 −3  mm 2 /s) than for leiomyoma (1.30 × 10 −3  mm 2 /s; p  〈 0.05) and mean cell density significantly higher for leiomyosarcoma (42.9%) than for leiomyoma (22.4%; p  〈 0.05). A strong negative correlation was seen between ADC and tumor cell density in Group 1 (Spearman, R  = −0.72; p  〈 0.05). ADC may help to differentiate benign from malignant uterine smooth muscle tumors, particularly tumors with high SI on T2WI and DWI.

Description: Purpose: To evaluate the role of computed tomography (CT) texture analysis in assessing response of soft tissue sarcoma (STS) treated with neoadjuvant bevacizumab (BVZ) plus radiotherapy in comparison to tumor size, density, and perfusion. Methods: In the phase II clinical trial, 20 patients with STSs received BVZ alone for 2 weeks followed by BVZ plus radiotherapy for 6 weeks prior to surgery. All patients received CT perfusion at baseline, 2 and 8 weeks after the therapy, and tumor blood flow (BF) was measured. In contrast enhanced CT image at the arterial peak enhancement time, mean of positive pixels (MPP) was measured as a texture parameter using texture analysis software, and tumor size and density were also measured. The percent changes of these parameters were compared with pathological response on surgical specimen. Results: After 2 weeks of the therapy, MPP and BF decreased by 10.42% and 20.08%, while changes of tumor size and density were not obvious. After 8 weeks, MPP, BF, and density decreased by 29.2% ( p  = 0.03), 53.2% ( p  = 0.001), and 30.41% ( p  = 0.005), respectively, without a significant change in size. The percent change of MPP after 8 weeks had a significant correlation with tumor necrosis in surgical specimen ( r  = −0.801, p  〈 0.001), whereas those of size, density, and BF did not. The receiver-operating characteristic analysis demonstrated that the percent change of MPP 〈 −35.36% was an optimal cut-off value to differentiate pathological responders. Conclusion: The change of MPP is the best biomarker for the treatment response in STS.

Description: We report here a rare case of undifferentiated carcinoma of the pancreas mimicking main-duct intraductal papillary mucinous neoplasm. In an 80-year-old woman, an approximately 8-mm papillary mass was incidentally detected at the downstream edge of a dilatated main pancreatic duct lumen on CT and MRI. Main pancreatic duct dilatation in the pancreatic body and tail and parenchymal atrophy were observed in the upstream of the mass. Histopathologically, the tumor protruded into the downstream edge of the dilatated main pancreatic duct lumen in the pancreatic body. The tumor cells had highly atypical nuclei and abundant polymorphic structures, and showed positive staining for granulocyte colony-stimulating factor, which led to the diagnosis of undifferentiated carcinoma. A total of 13 cases of undifferentiated carcinoma with intraductal tumor growth have been reported to date. The case report by Bergmann et al. has been the smallest in histopathological specimen, and the present case is the smallest in size detected by radiological images. Since early undifferentiated carcinoma of the pancreas can resemble those of main-duct intraductal papillary mucinous neoplasm in cross-sectional images, we have to consider undifferentiated carcinoma in the differential diagnosis of the solitary and papillary mass with low contrast enhancement in early phase in the main pancreatic duct.

Description: A 50-year-old postmenopausal woman, who underwent ultrasonography at a periodic medical checkup, was found to have bilateral ovarian masses. Pelvic magnetic resonance imaging (MRI) showed bilateral multilocular cystic ovarian masses. The cyst walls and septal structure demonstrated contrast enhancement. She underwent bilateral salpingo-oophorectomy. Microscopic examination revealed that the cysts were lined with cuboidal or columnar epithelial cells, and some of the cells were ciliated. The final histopathological diagnosis was endosalpingiosis. Endosalpingiosis is defined as the presence of ectopic ciliated epithelium, resembling the normal endosalpinx, without endometrial stroma. It rarely presents as a tumor-like mass on MRI.

Description: Purpose Portacaval lymphadenopathy (PCLA) is common in cirrhosis and chronic viral hepatitis and is frequently an incidental finding on abdominal CT scans. We aimed to detect the incidence of malignancy in organs drained by portacaval nodes in patients with PCLA associated with cirrhosis or chronic viral hepatitis, or incidentally detected PCLA. Methods We searched CT reports from 2005 to 2007 for the phrases “periportal node” and “portacaval node.” MDCTs of patients with portacaval nodes ≥10 mm in maximal short-axis size on contrast-enhanced MDCTs, were included. Records were reviewed for presence of malignancy, liver metastases, chronic viral hepatitis, and cirrhosis. Clinical or imaging follow-up ≥6 months was performed to detect if malignancy developed in organs drained by portacaval nodes in patients with incidental PCLA, cirrhosis, or chronic viral hepatitis. Results 479 patients met inclusion criteria [298 males (62%), mean age 61.4 years]. In 285 (59.5%) patients, PCLA was explained by local pathology or systemic lymphadenopathy. PCLA was incidental in 146 (30.5%) patients. Of these, 112 (76.7%) had ≥6 months of follow-up (median 26 months). No patient with incidental PCLA developed malignancy in organs drained by these nodes. Cirrhosis or chronic viral hepatitis was present in 48 (10.0%) patients. Of these, 42 (87.5%) had ≥6 months follow-up (median 28 months), and only 1 patient developed cholangiocarcinoma (positive predictive value 2.4%). Conclusions Development of malignancy is rare in patients with PCLA, either incidental or secondary to cirrhosis or chronic viral hepatitis. Our study suggests that no follow-up of PCLA is required in these settings.

Description: Purpose Polypoid adenomyoma (PA) is an uncommon benign tumor of the uterus appearing as a submucosal polypoid mass, or rarely as a subserosal polypoid mass. PA should be differentiated from atypical polypoid adenomyoma or malignant uterine tumors. The purpose of our case series is to evaluate magnetic resonance (MR) manifestations of PA for the differential diagnosis. Methods Seven cases with surgically proven PA, five submucosal, and two subserosal, were evaluated. MR imaging findings including contrast enhancement in six cases (four cases with dynamic contrast-enhanced MR study), diffusion-weighted imaging (DWI) in five cases, and susceptibility weighted imaging (SWI) in two cases were retrospectively reviewed. Results All seven lesions exhibited isointensity compared with the myometrium and 4 of 7 lesions (57%) contained high signal intensity hemorrhagic areas on T1-weighted images. On T2-weighted images, signal intensity was variable and all seven lesions contained cysts. None of five lesions with DWI exhibited high signal intensity compared with the normal myometrium. All six lesions showed intense contrast enhancement similar to that of the myometrium on post-contrast T1-weighted images. Punctate low intensity areas reflecting blood contents were revealed in all two lesions with SWI. Conclusions Submucosal or subserosal polypoid masses containing hemorrhagic areas, and cysts reflecting functional endometrium and dilatation of endometrial glands are suggestive for PA. Intense contrast enhancement similar to that of the myometrium may be another characteristic finding for PA.

Description: Purpose To determine (1) the sensitivity for detection of small polyps with varying MR slice thicknesses using a resolution phantom; (2) reader confidence in polyp detection; and (3) image acquisition time. Methods A resolution phantom was created using a 3D printer. Polyp morphologies were sessile (height = diameter), flat (height = 1/2 diameter of the base), and pedunculated (stalk length = polyp diameter). Polyp diameters were 5, 7, 10, and 12 mm. Images were acquired with section thicknesses of 5, 3, and 1 mm. Images were independently reviewed by 4 board-certified radiologists who were blinded to phantom design and sequences parameters. Readers recorded maximal polyp diameter and confidence level that a polyp was present on a 1–100 point scale. Image acquisition time was also recorded. Results All polyps were detected by all 4 readers in the 5-mm-section thickness series. All polyps were detected by 3 readers in the 3- and 1-mm-section thickness series. The fourth reader identified 11/12 polyps in the 3- and 1-mm-section thickness series. Confidence levels were not statistically significantly different for the different section thicknesses ( p  = 0.28). Increasing the section thickness from 1 to 5 mm decreased image acquisition time from 3 min 54 s to 41 s. Conclusions Five-millimeter-section thickness was adequate for identification of 5–12 mm polyps regardless of shape. Pending further reduction in acquisition time, this prototype sequence holds promise for segmental imaging of the colon with MR colonography.

Description: Gastric-type adenocarcinoma (GAS) of the uterine cervix is a recently defined subtype of mucinous adenocarcinoma. GAS is proposed to include minimal deviation adenocarcinoma (MDA) as a very well-differentiated form and has been suggested to arise from lobular endocervical glandular hyperplasia (LEGH). We report the magnetic resonance imaging (MRI) findings of a GAS associated with LEGH. On MRI, the LEGH component was detected as multiple cystic lesions arranged in a “cosmos pattern”, while the GAS was depicted as a predominantly solid lesion containing obvious adenocarcinoma and MDA components, which appeared as mass-like and infiltrative components, respectively. The GAS exhibited tiny cysts on three-dimensional T2-weighted images, high intensity on diffusion-weighted images mostly due to T2 shine-through effect according to apparent diffusion coefficient (ADC) map, and reticular enhancement on dynamic contrast-enhanced MRI, which reflected numerous dilated glandular structures of the tumor. Low ADC was only observed at the deepest invasion front of the obvious adenocarcinoma component. Our case suggests that the MRI features of GAS vary depending on the tumor’s histological components, and it is important to be aware of these imaging features when evaluating LEGH on MRI.

Description: We present a rare case of testicular seminoma in persistent Mullerian duct syndrome (PMDS) with transverse testicular ectopia (TTE). A 42-year-old man noticed scrotal swelling a few weeks earlier and underwent magnetic resonance imaging (MRI) on suspicion of testicular tumor. MRI revealed a normal left testis on the left side of the left scrotum and a heterogeneous mass on the right side within the left scrotum. No right testis was found in the right scrotum. A blind-ending tubular structure with thickened wall showed a three-layer appearance on T2-weighted imaging and extended from the prostate through the left inguinal canal to the left scrotum. Findings during surgery suggested right testicular tumor associated with right TTE. The histopathological and immunohistochemical diagnoses of the testicular tumor and blind-ending tubular structure were seminoma and persistent Mullerian duct, respectively. Testicular tumor in PMDS with TTE is rare but may possess a characteristic appearance on imaging. Proper knowledge of these diseases will allow correct preoperative diagnosis.

Description: Purpose The purpose of this study is to compare the MRI features of intestinal and endocervical mucinous borderline ovarian tumors (MBOT). Methods Fifty seven and 17 patients with histologically proven intestinal ( n  = 62) and endocervical ( n  = 22) MBOT, respectively, underwent preoperative MRI which were reviewed by two radiologists blinded to histology. An array of MRI features and clinical factors (age, cancer antigen 125 [CA-125]) were compared between intestinal and endocervical subtypes using the t test and Chi-square test. Univariate and multivariate logistic regression analyses were performed to evaluate for significant predictors of subtype. Results There was no significant difference in patient age of intestinal and endocervical MBOT ( P  = 0.423). CA-125 levels were higher in endocervical MBOT ( P  = 0.022). Regarding MR features, intestinal MBOT was larger, had more septations, more frequently demonstrated honeycomb loculi, and signal intensity discrepancy while endocervical MBOT was more frequently bilateral with papillary projections ( P  〈 0.05). At multivariate analysis, higher CA-125 (odds ratio [OR] 1.015, P  = 0.034) and the presence of papillary projections (OR 11.441, P  = 0.024) were the only independent predictive factors of endocervical MBOT. Conclusion Intestinal and endocervical subtypes of MBOT demonstrated significantly different features on MRI. The presence of papillary projection was the only independent MRI feature predictive of endocervical MBOT.