CT findings of thoracic manifestations of primary Sjögren syndrome: radiologic-pathologic correlation.

Primary Sjögren syndrome is an immune-mediated exocrinopathy characterized by lymphoplasmacytic infiltration of the salivary and lacrimal glands. Various systemic extraglandular disorders are associated with primary Sjögren syndrome, and the thorax is commonly affected. The pulmonary manifestations of primary Sjögren syndrome may be categorized as airway abnormalities, interstitial pneumonias, and lymphoproliferative disorders; in each category, bronchiectasis or centrilobular nodules, nonspecific interstitial pneumonia, and lymphoid interstitial pneumonia are common. These manifestations do not usually occur in isolation; they are concomitantly seen with other types of lesions. Mucosa-associated lymphoid tissue (MALT) lymphoma and amyloidosis are key components of lymphoproliferative disorders, and MALT lymphoma should always be considered because its morphologic characteristics are similar to those of benign lymphoproliferative disorders. Amyloidosis is rare but important because it carries a risk for underlying MALT lymphoma or plasmacytoma, and it may lead to hemoptysis during biopsy. In addition, thin-walled air cysts are characteristic of primary Sjögren syndrome, irrespective of the main pulmonary manifestations. Lymphadenopathy and multilocular thymic cysts may be seen in the mediastinum. During the follow-up period, there is a risk for acute exacerbation of interstitial pneumonia and development of malignant lymphoma. Often, primary Sjögren syndrome is subclinical, but there are various underlying risks. Thus, imaging findings are important. In addition to the various types of interstitial pneumonia and airway abnormalities, air cysts and mediastinal manifestations may help diagnose primary Sjögren syndrome.

Retrospective analysis of contrast-enhanced computed tomographic findings related to obstructive shock due to ascending aortic dissection.

OBJECTIVE: The objective of this study was to evaluate contrastenhanced computed tomography findings related to obstructive shock due to ascending aortic dissection (AAD). METHODS: The computed tomography findings in 9 AAD patients with shock, 11 AAD patients without shock, and 18 control subjects were evaluated for (1) pericardial effusion, (2) diameter of the inferior vena cava, (3) periportal hypodensity, (4) retrograde reflux of contrast material, (5) aortic and visceral enhancement, and (6) other factors (peripancreatic edema, bowel thickening/dilatation). RESULTS: Patients with shock showed the highest ratio of pericardial effusion, periportal hypodensity, and retrograde reflux of contrast material; largest inferior vena cava diameter; stronger aortic enhancement in both the arterial and portal phases; lowered splenic and pancreatic enhancement in the arterial phase; and stronger visceral (especially adrenal) enhancement, except for the renal medulla in the portal phase. CONCLUSIONS: Computed tomography findings related to obstructive shock due to AAD reflected impaired diastolic filling, decreased cardiac output, and flow redistribution in visceral organs.

Aneurismal type of colorectal cancer: imaging characteristics of gastrointestinal endoscopy, computed tomography and magnetic resonance imaging.

BACKGROUND/AIMS: Only a few studies have investigated aneurismal large-intestinal malignant diseases. The present study reported five cases of aneurismal colon cancer that were experienced over 20 years. The present study aims to define the pathological and diagnostic imaging characteristics of aneurismal colon cancer. METHODOLOGY: A case series from a retrospective review of large-intestinal malignant tumors at Saga Medical School, Japan. Barium enema was performed in 876 patients with large-intestinal advanced cancer, which included five with aneurismal-type cancer. RESULTS: The characteristics of the 5 cases were as follows: (i) pathological findings were poorly differentiated adenocarcinoma without desmoplastic change or mucinous adenocarcinoma; (ii) a typical aneurismal type revealed by barium enema had a low elevated tumor edge without stenosis upon endoscopic examination; (iii) computed tomography showed low attenuation without enhancement of contrast material; and (iv) magnetic resonance imaging indicated high intensity in the T2-weighted images of mucinous adenocarcinoma. CONCLUSION: We revealed 5 cases of aneurismal colon cancer, which had characteristic pathological findings and diagnostic imaging, and poor prognosis.

High b-value diffusion-weighted MRI in differentiation between benign and malignant polypoid gallbladder lesions.

BACKGROUND: Several studies have reported the effectiveness of high b-value diffusion-weighted MR imaging (DWI) in the abdominal region, and have found that various malignant tumors may show high signal intensity on DWI, reflecting their high cellularity and/or their long relaxation time. The value of ADC measurement has also been documented for the diagnosis of several abdominal malignancies. PURPOSE: To retrospectively evaluate the usefulness of high b-value DWI in differentiating between benign and malignant polypoid gallbladder lesions. MATERIAL AND METHODS: The study population consisted of 10 benign (three hyperplastic polyps and seven adenomas) and 13 malignant (all adenocarcinomas) polypoid gallbladder lesions. DWI was evaluated by two observers. Qualitatively, the signal intensity of the lesions on DWI was visually evaluated and categorized as iso, high, or very high. Quantitatively, the ADC values of the lesions were measured from ADC maps. Statistical analysis was performed using a two-tailed Fisher's exact test and the Mann-Whitney test, respectively. RESULTS: Qualitative analysis revealed a statistical difference (P = 0.0041). Six of 10 benign lesions were categorized as iso, and the remaining four were categorized as high. In the 13 malignant lesions, one was categorized as iso, five as high, and seven as very high. The ADC values of the malignant lesions (1.34 ± 0.50 × 10(-3) mm(2)/sec) were significantly lower than those of the benign lesions (2.26 ± 0.44 × 10(-3) mm(2)/sec) (P = 0.00016). CONCLUSION: High b-value DWI may be useful for differentiating between benign and malignant polypoid gallbladder lesions by the visual assessment of DWI and ADC measurement.

Magnetic resonance imaging of large chromophobe renal cell carcinomas.

PURPOSE: The objective of this study was to clarify the magnetic resonance imaging (MRI) findings of large chromophobe renal cell carcinomas. MATERIALS AND METHODS: Five patients diagnosed pathologically with chromophobe renal cell carcinoma are included. MRI findings were retrospectively evaluated for the tumor contour, uniformity and hypointensity of the rim of the tumor on T2-weighted images, "microscopic fat," enhancement degree and pattern on dynamic study, and necrosis in the tumor, among other findings. RESULTS: The tumor size ranged from 4.8 to 13.7 cm (mean 7.9 cm). The tumor contour was well defined in four patients. All but one tumor showed a hypointensity rim, and all tumors had a heterogeneous appearance on T2-weighted images. "Microscopic fat" was detected in one case. All tumors demonstrated low enhancement compared to that of the renal cortex. All tumors showed heterogeneous enhancement on postcontrast images. Necrosis was seen in four. Hemorrhage and renal vein thrombosis was seen in one. CONCLUSION: Chromophobe renal cell carcinomas of large size tend to have a heterogeneous appearance on postcontrast and T2-weighted images, a well-defined tumor contour with a hypointensity rim on T2-wighted images, and lower enhancement than that of the renal cortex. Tumor necrosis is easily apparent, and "microscopic fat" may be observed.

Organotypic culture of human bone marrow adipose tissue.

The precise role of bone marrow adipose tissue (BMAT) in the marrow remains unknown. The purpose of the present study was therefore to describe a novel method for studying BMAT using 3-D collagen gel culture of BMAT fragments, immunohistochemistry, ELISA and real-time reverse transcription-polymerase chain reaction. Mature adipocytes and CD45+ leukocytes were retained for >3 weeks. Bone marrow stromal cells (BMSC) including a small number of lipid-laden preadipocytes and CD44+/CD105+ mesenchymal stem cell (MSC)-like cells, developed from BMAT. Dexamethasone (10 micromol/L), but not insulin (20 mU/mL), significantly increased the number of preadipocytes. Dexamethasone and insulin also promoted leptin production and gene expression in BMAT. Adiponectin production by BMAT was <0.8 ng/mL under all culture conditions. Dexamethasone promoted adiponectin gene expression, while insulin inhibited it. This finding suggests that dexamethasone, but not insulin, may serve as a powerful adipogenic factor for BMAT, in which adiponectin protein secretion is normally very low, and that BMAT may exhibit a different phenotype from that of the visceral and subcutaneous adipose tissues. BMAT-osteoblast interactions were also examined, and it was found that osteoblasts inhibited the development of BMSC and reduced leptin production, while BMAT inhibited the growth and differentiation of osteoblasts. The present novel method proved to be useful for the study of BMAT biology.

Irradiated fibroblast-induced bystander effects on invasive growth of squamous cell carcinoma under cancer-stromal cell interaction.

The irradiated fibroblast-induced response of non-irradiated neighboring cells is called 'radiation-induced bystander effect', but it is unclear in non-irradiated human squamous cell carcinoma (SCC) cells. The present study shows that irradiated fibroblasts promoted the invasive growth of T3M-1 SCC cells, but not their apoptosis, more greatly than non-irradiated fibroblasts, using collagen gel invasion assay, immunohistochemistry and Western blot. The number of irradiated fibroblasts decreased to about 30% of that of non-irradiated fibroblasts, but irradiated fibroblasts increased the growth marker ki-67 display of SCC cells more greatly than non-irradiated fibroblasts. Irradiated fibroblasts did not affect the apoptosis marker ss-DNA expression of SCC cells. Irradiated fibroblasts enhanced the display of the following growth-, invasion- and motility-related molecules in SCC cells more greatly than non-irradiated fibroblasts: c-Met, Ras, mitogen-activated protein kinase (MAPK) cascade (Raf-1, MEK-1 and ERK-1/2), matrix metalloproteinase-1 and -9, laminin 5 and filamin A. Irradiated fibroblasts, but not non-irradiated ones, formed irradiation-induced foci (IRIF) of the genomic instability marker p53-binding protein 1 (53BP1) and expressed transforming growth factor-beta1 (TGF- beta1). Irradiated fibroblasts in turn enabled SCC cells to enhance 53BP1 IRIF formation more extensively than non-irradiated fibroblasts. Finally, effects of irradiated fibroblasts on growth and apoptosis of another HEp-2 SCC cell type were similar to those of T3M-1. These results suggest that irradiated fibroblasts promotes invasion and growth of SCC cells by enhancement of invasive growth-related molecules above through TGF- beta1-mediated bystander mechanism, in which irradiated fibroblast-induced genomic instability of SCC cells may be involved.

Fitz-Hugh-Curtis syndrome. Radiologic manifestation.

OBJECTIVES: To clarify radiologic findings of Fitz-Hugh-Curtis syndrome (FHCS). METHODS: Thirteen women with right upper abdominal pain who were clinically diagnosed with FHCS were included. Biphasic helical computed tomography (CT) of the abdomen was performed in all patients. Posttherapeutic follow-up CT was available in 7 patients. Ultrasonography (US) was also performed in 12 patients. These imaging findings were reviewed retrospectively. RESULTS: On enhanced CT, hepatic and splenic capsular enhancement was identified in 13 and 4 patients, respectively. Hepatic capsular enhancement on the early phase, which was detected in all patients, disappeared after treatment. No adhesive band or fluid collection around the liver was evident. No enhancement of the "bare area" of the liver and spleen was seen. No definite abnormality of the liver or perihepatic region was detected by US. CONCLUSIONS: Hepatic and splenic capsular enhancement on abdominal enhanced CT may be characteristic of FHCS. Enhanced CT may be a useful and noninvasive modality to help a diagnosis of FHCS, especially in young women with right upper abdominal pain without significant findings on US and gastrointestinal endoscopy.