membranous type has a high recurrence rate of 25%–37%, prob- ably because of its tendency to be multilobulated and unencap- sulated. 5 Therefore, the membranous type of BCA should be clas- sified separately from other BCAs. In our study, only one case was membranous type, which showed stronger enhancement than the other types of the tumors. Size, morphology, and SI could not distinguish this type and the other subtypes. This enhancement behavior might be one characteristic MR finding for the mem- branous type (Fig 1).
This series included 16 women (72.8%) and 6 men (27.2%), aged between 32 and 73 years (mean 51.5 years, SD 10.2 years). In 4 patients, the tumor was found during an incidental healthy examination. Seventeen patients presented with a pal- pable mass without tenderness, while 1 patient had slight pain. The CT and sonography characteristics of the tumors are summarized in the On-line Table. All 22 cases were single lesions. Fifteen tumors were on the left parotidgland, while the remaining tumors were located on the right side. The tu- mors were located in the superficial lobe in 19 patients (type 1 ⫽ 11; type 2 ⫽ 8) and in the deep lobe (type 3) in 3 cases. On CT, 21 cases showed well-defined borders (Fig 1), while 1 case (case 14, a type 2 tumor) showed heterogeneous enhancement with ill-defined borders (Fig 2). On sonography, all 20 cases showed a round or oval nodule, and 19 cases displayed well- defined borders. The CT attenuation of the soft-tissue portion of the tumors on unenhanced CT was 38.6 ⫾ 9.5 HU (mean ⫾ SD). The soft-tissue components showed early intense en- hancement after contrast injection; the postcontrast CT atten- uation was 103 ⫾ 19.4 HU (mean ⫾ SD) and the CT attenu- ation increase was 64.5 ⫾ 19 HU (mean ⫾ SD).
The differential diagnosis includes benign and malignant parotid tumors, especially Warthin tumors and adenoid cystic carcinomas, which may also have a solid cystic appearance. These tumors rarely occupy the total gland parenchyma. In particular, Warthin tumors are bilateral in up to 10% of cases reported. They present as well-circum- scribed, partly cystic and partly solid lesions on MRI and are often located in the tail of the parotidgland. Adenoid cystic carcinoma usually presents as an infiltrating mass with a high propensity for perineural invasion. On MRI adenoid cystic carcinoma has an irregular contour, poorly defined margins, and a strong enhancement after the administration of contrast medium .
each of these patients. CT showed a well- defined round mass, with an average maximum diameter of 19.8 ± 8.5 mm. Heterogeneous enhancement was also observed. Only two of the eight tumors (25%) showed cystic degener- ation (Table 1). In these patients, the surgical treatment included dissection of the facial nerve and excision of the tumor and superficial lobe of the parotidgland. Three of the eight patients (37.5%) underwent preoperative fine needle aspiration biopsy (FNAB). The FNAB examination revealed a BCA in one patient (12.5%), while in the other two (25%) patients, it indicated the presence of benign tumors. The other five tumors were diagnosed on pathologi- cal examination. No facial nerve injury and no postoperative tumor recurrence occurred in this group (Table 2; Figure 2A, 2B).
by the neck (especially the parotid region), mediastinum, retroperitoneum, and groin [4, 9]. The presence of stranding of cutaneous fat adjacent to the primary site of the MCC on CT scans may suggest the presence of edema from lymphatic invasion . Furthermore, imaging work-up of soft tissue lesions is best performed with magnetic resonance imaging (MRI). However, there are only a few studies describing the MRI findings in such cases, which have reported the presence of inhomogeneous signal intensities on T1 and T2 weighted images . 18 F-FDG-PET has an important role in diagnostic imaging of MCC, and 18 F-FDG-PET/CT may also provide more accurate anatomic localization of tumors [4, 6]. Peloschek et al. reported that 18 F-FDG-PET has a sensitivity of 85.7% and a specificity of 96.2% compared with those of 95.5% and 89.1% for conventional imaging modalities, respectively . Based on the above mentioned findings, 18 F- FDG-PET, US, CT, or MRI may be useful in patients with suspected metastatic MCC.
weighted images, with more frequent cystic change. The basalcelladenoma is sometimes mistaken for adenoid cystic carcinoma. There are two features that help to distinguish these lesions. One is the circum- scription of the basalcelladenoma, which contrasts with the invasive pattern of adenoid cystic carcinoma. The other is the lack of vascularity in the microcystic areas of adenoid cystic carcinoma, which contrasts with the numerous endothelial-lined channels in basalcelladenoma. Although basalcell adenocarcinoma is an epithelial neoplasm that has the cytological char- acteristics of basalcelladenoma (10), it is character- ized by invasive and destructive morphologic growth, in contrast to the noninvasive appearance of basalcelladenoma. Even in the multinodular forms of mem-
Our study suggests that no one MR finding distinguished pleomorphic adenomas from other parotidgland tumors. None of the signs evaluated had perfect sensitivity and specificity. However, tumors that had a complete capsule, lobulation, and high signal on T2-weighted im- ages were most likely pleomorphic adenomas. Only benign tumors had both lobulation of the contour and a complete capsule. Well-defined margins were also a good predictor of a benign tumor. Tumor margins and capsule are better defined on T2-weighted than T1-weighted im- ages. Because contrast enhancement improves the demonstration of the capsule on T1- weighted images, intravenous contrast medium may be useful, especially in cases with clinical signs and symptoms of malignancy (pain or facial nerve paralysis).
PURPOSE: To compare six MR sequences (plain and gadolinium-enhanced fat suppressed T1- weighted spin echo, T2-weighted standard spin echo, fat-suppressed and non–fat-suppressed T2-weighted fast spin echo, and inversion-recovery T2-weighted fast spin echo) in their ability to detect, delineate, and characterize lesions of the parotidgland. METHODS: Fifty-eight parotidgland lesions imaged on 47 examinations were retrospectively evaluated by three blinded observ- ers. Several outcome-related variables were compared by the above six sequences: imaging time, image quality, anatomic sharpness of parotid space, subjective lesion conspicuity, detected ab- normality volume, number of individual lesions or discrete lobulations, conspicuity of invasion into adjacent boundaries and structures, and overall diagnostic value. RESULTS: Differences in the above outcome variables between sequences did not correlate with MR scanner software upgrade level, coil type, or lesion-dependent characteristics. Fat-suppressed fast spin-echo T2-weighted and inversion-recovery fast spin-echo T2-weighted sequences resulted in significantly higher scores for lesion conspicuity, detected abnormality volume, and overall diagnostic value. T1- weighted images resulted in the next highest scores, whereas gadolinium-enhanced T1-weighted and standard spin-echo T2-weighted sequences performed poorly for most parotid lesions. CONCLUSION: MRimaging of the parotidgland should include fat-suppressed, long-repetition- time, fast spin-echo T2-weighted, and T1-weighted sequences. Gadolinium-enhanced images need not be obtained routinely.
Classification of MPGT is controversial. In 1996, Seifert and Donath reviewed the nomenclature of these tu- mors with regard to their localization, classifying them as: bilateral parotid tumours, unilateral multifocal parotid tumours and the combination of bilateral parotid tumours with unilateral multifocal parotid tumours . As re- gard the chronology, classification is not clear; some authors indicate an interval of 6 months or more from the diagnosis of the first tumor, to define a second tumor as metachronous . However, this parmeter presents some problems related to the diagnosis because the identification of a lesion depends on dimensions and local- ization of the tumor (superficial or deep lobe of the gland), and on presence or not of symptoms. For example, early tumors, with no symptoms, located in the salivary gland deep lobe can go unnoticed.
Salivary gland tumors, includ- ing malignancy, represent a he- terogeneous group of patholo- gy, so it is difficult to under- stand their molecular patho- genesis and genetic altera- tions. As is well known, PA is the most common benign tu- mor of the parotidgland, and the World Health Organization classification reported that 3-4% of all pleomorphic adenomas become malig- nant . Carcinoma ex-pleomorphic adenoma (CXPA) is defined as a carcinoma arising from a primary or recurrent PA [8, 32]. Unlike PA, Warthin’s tumor presents less than a 1% risk of malignant transformation . We collected 32 surgically treated salivary tumors and analyzed their clinicopathologic and molecular biologic Figure 2. Scatter plot of telomere length (A), PIK3CA amplification (B), and
The affected spinal cord segments identified by MRimaging (n ⫽ 8), were grayish in color, had a nodular appearance, and were gritty during surgical excision. The hypointense signals detected in two cases were correlated with areas of attenuated fibrosis (Fig 3B). Intramedullary nodular contrast enhancement was cor- related to multiple schistosomiasis microtubercles found in histopathologic sections of all patients. Schistosoma ova were seen surrounded by granulomatous chronic inflammatory cells: eosinophils, lymphoplasma cells, and macrophage histiocytes. The peripheral enhancing lesions in MRimaging were correlated to thickened infested leptomeninges at surgery and in pathology. The leptomeninges showed the chronic granulomatous in- flammatory cells, as well as the presence of schistosoma eggs. The resected nerve roots in the four MR-positive cases were thickened by a chronic granulomatous in- flammatory process surrounding schistosoma eggs.
parotid ultrasound and the clinical features, including clinical symptoms, laboratory tests, and pathology, were analyzed. The results showed that the proportion of patients with SS with ultrasound changes (Elke’s simplification score ≥ 1) was as high as 95.8%, especially in primary Sjögren’s syndrome, but in patients with other rheumatisms, the positive rate of SGUS was low, which suggests that the speci- ficity of parotid ultrasound in the diagnosis of primary Sjögren’s syndrome is better (P < 0.05). A previous study reported that parotid ultra- sound has a higher value in pSS, but there are few studies on the difference between pSS and sSS. A study by Cornec et al. showed that the positive rate of parotid ultrasound was 62.8% and 12.5% in pSS and sSS patients, respec- tively. In this study, with reference to the cur- rently accepted ultrasound standard, the boundary value of SS was 2. The results showed that the positive rate of SGUS in pSS was 65.0%, and the positive rate in sSS was 41.6%. Although our data is different from the counter- part report of Cornec , the conclusion that SGUS is more sensitive than sSS in pSS is consistent. Hence, we believe that the sputum
This retrospective study was reviewed and approved by our institu- tional review board. The study included 10 patients (9 men and 1 woman; mean age, 58 years; age range, 17–76 years) with clinically proved UE who had abnormalities on brain imaging when examined between May 2005 and December 2014. Eleven potential patients were identified by a search of the imaging archive at our institution for patients who had the LFS on MRimaging. Imagingfindings and medical records of these 11 patients were reviewed. Two of the pa- tients were excluded because of other toxic/metabolic diseases, such as extrapontine myelinolysis. One additional patient who underwent MRimaging after a clinical diagnosis of UE was subsequently iden- tified and included. UE diagnoses in patients were clinical and sup- ported by laboratory findings showing deterioration of renal func- tion and typical neurologic complications. Other possible causative
Microscopic examination of incisional biopsy specimen showed principally basaloid cells arranged in clumps with hyperchromatic nuclei and increased nu- clear-cytoplasmic ratio. A probable diagnosis of benign monomorphic adenoma of salivary gland was made. Surgery was planned and tumor was excised along with a safe margin after ligating greater palatine vascular bundle and the defect was repaired by buccal fat pad (BFP). The excised pathology was submitted to the de- partment of Oral and Maxillofacial Pathology where the routine tissue processing was carried out. The histo- pathological examination of the excised specimen re- vealed well-encapsulated tumormass which was com- posed of monomorphic basaloid cells arranged in the form of solid nests and trabeculae pattern in the loose connective tissue stroma. The peripheral cuboidal cells
pressive therapy, 9 had enhancing dural or parenchymal le- sions that were T2-hypointense relative to gray matter. One of these patients is illustrated in Fig 5. Therefore, we performed a subanalysis to determine whether T2-hypointense lesions were less likely to improve than other imaging abnormalities. Thirteen of 27 patients who had follow-up data had ⱖ 1 en- hancing lesion that was T2-hypointense relative to gray mat- ter. Only 4 of these 13 (31%) patients with enhancing T2- hypointense lesions showed significant improvement during follow-up compared with 10 of 14 (72%) patients who did not have such lesions (P ⫽ .05). In terms of clinical improvement with immunosuppressive therapy (after excluding patients who received only symptomatic treatment), 4 of 7 (57%) pa- tients with T2-hypointense lesions reported significant relief in their symptoms versus 12 of 13 (92%) patients without such lesions.
hypointense on T2WI), amelanotic pattern (hypointense or isointense on T1WI and hyperintense or isontense on T2WI), indeterminate or mixed pattern (MRimaging characteristics not conforming to the first 2 categories), and hematoma pat- tern (MRimaging exhibiting only hematoma characteris- tics). 27 In our study, cases with ⬎10% of melanin-containing cells showed a melanotic pattern, while case 2 did not have typical MRimaging and was then proved to have ⬍10% melanin-containing cells by histopathology.
It is reasonable to consider that the MRimaging pattern may reflect the chronic and acute nature of the obstruction. In this context, type I patients are those with relatively acute and incomplete obstruc- tion associated with secondary infection. Type II patients are those with chronic and complete ob- struction, but this obstruction is not associated with secondary infection. Type III patients are those with a nonobstructing or partially obstructing sial- olith without secondary infection. On the other hand, involvement of the sublingual gland, as evi- denced by MRimaging (patients 1 and 5), was as- sociated with pus discharge from the orifice of the gland. A sialolith located near the orifice was not always associated with sublingual gland involve- ment and pus discharge from the orifice, or vice versa. Furthermore, a patient with pus discharge (patient 3) had a stone in the middle part of the main duct yet he did not have any abnormal MRimaging features of the sublingual gland on MR.
ules were well circumscribed with smooth margins. On MRimaging, marked hyperintensity on T2-weighted images was noted in 18/21 (85%) patients (Figs 1 and 2). Three patients had lesions that were iso- to hypointense on T2-weighted im- ages relative to the normal parotid tissue. There was a variable pattern of enhancement, ranging from peripheral enhance- ment (9/21 patients) (Fig 3) to solid enhancement (2/21 pa- tients) to mixed heterogeneous solid and peripheral enhance- ment (6/21 patients) (Fig 4B). There was no enhancement in 3/21 patients. Gadolinium-enhanced images were nondiag- nostic in 1 patient. Five patients had large infiltrative mul- tiloculated T2 hyperintense lesions, of which 3 demonstrated peripheral enhancement and 2 demonstrated both peripheral and solid enhancement (Fig 4). The 3 patients who underwent enhanced CT imaging demonstrated marginated solidly en- hancing lesions. Recurrent nodules in the subcutaneous tissue were seen in 14/24 patients (Figs 1A and 5). Several of the lesions were tiny, ranging from 2 to 6 mm (13/24 patients) (Figs 1 and 2). Lesions were not confined to the parotid but were seen in areas distant from the operative bed, including the postauricular region, the masticator space, the parapha- ryngeal space, and inferior to the parotid tail along the carotid sheath (7/24 patients) (Figs 1B and 6).