Retroperitoneal bronchogenic cyst: a case report

A 46-year-old woman presented with a 1-year history of progressive left-arm numbness. A cyst below the left hemidiaphragm was discovered incidentally when a CT scan was performed to examine the thymus for a suspected tumor. A thymic mass was found. MRI indicated that the cyst contained proteinaceous fluid. The thymoma was approached through a median sternotomy and resected, but the cyst was found to be infradiaphragmatic. A separate, left paraspinal incision was made to access the retroperitoneum, and the cyst was resected. Histologic examination showed that the cyst was bronchogenic in origin. Retroperitoneal bronchogenic cysts are very rare, and only four cases have been reported in the English-language literature.     

Effects of home-based combined resistance training and walking on metabolic profiles in elderly Japanese

Background: To evaluate the effects of home‐based combined resistance training and walking on metabolic profiles in elderly Japanese subjects. Methods: Two hundred and forty‐four elderly Japanese participants were divided into two groups (184 training group and 60 controls). Each exercise training session consisted of one set of 10 repetitions of 11 different resistance exercises, and the training lasted 12 weeks. Fasting blood samples were obtained for measurements of serum levels of total cholesterol, high‐density lipoprotein cholesterol (HDL‐C), triglycerides, hemoglobin A_1c, insulin and plasma glucose, before and after the training period. We estimated insulin resistance using the homeostasis model assessment. Five subjects further underwent a two‐step hyperinsulinemic‐euglycemic clamp to evaluate insulin action directly before and after the training. Results: Training resulted in a significant increase in HDL‐C (60 ± 1–62 ± 1 mg/dL, mean ± SE, P < 0.01) and a significant decrease in triglycerides (115 ± 5–106 ± 4 mg/dL, P < 0.05), while no significant changes were observed for total cholesterol, plasma glucose, insulin, homeostasis model assessment or hemoglobin A_1c. Glucose infusion rates during the hyperinsulinemic‐euglycemic clamp increased by 30% (P < 0.05) at the 40 mU/m² per min infusion rate, from 5.4 ± 0.9 to 7.0 ± 1.1 mg/kg per min and by 15% (P < 0.01) at the 400 mU/m² per min infusion rate, from 9.4 ± 1.0 to 10.8 ± 1.2 mg/kg per min. In the control group, no significant changes were noted except for a significant decrease in HDL‐C. Conclusions: Our home‐based exercise program for elderly is safe and effective for improving metabolic profiles.     

Concurrent occurrence of allergic granulomatous angiitis and temporal arteritis: a case report and review of the literature

Allergic granulomatous angiitis (AGA) is a disease entity that was first distinguished from classical polyarteritis nodosa by Churg and Strauss in 1951, and is characterized by the clinical features of allergic rhinitis or bronchial asthma, eosinophilia, and vasculitis. Allergic granulomatous angiitis has been described to mainly involve small vessels. We herein describe a case of Churg–Strauss syndrome which demonstrated the clinical and laboratory findings supporting a diagnosis of AGA and was also associated with the clinical and pathological findings for temporal arteritis, which was characterized by eosinophil infiltration and granuloma formation of the temporal artery (middle-sized vessel).     

Difference in the distribution of tumor-infiltrating CD8+ T cells and FOXP3+ T cells between micronodular thymoma with lymphoid stroma and micronodular thymic carcinoma with lymphoid stroma

Micronodular thymoma with lymphoid stroma (MNT) is a rare thymic epithelial neoplasm subtype characterized by a micronodular tumor cell growth pattern and abundant lymphoid stroma. Micronodular thymic carcinoma with lymphoid stroma (MNCA) is considered as a malignant counterpart of MNT and exhibits a growth pattern similar to that of MNT but has histologic features reminiscent of thymic squamous cell carcinoma, such as cytologic atypia and CD5 and CD117 immunoexpression. Although both MNT and MNCA are characterized by abundant lymphoid stroma, it remains unknown whether there are differences in infiltrating lymphocytes between MNT and MNCA. We analyzed the immune microenvironment profile in eight MNT and three MNCA cases. The cell density of CD8-positive T cells was significantly higher in MNT than in MNCA, whereas that of FOXP3-positive T cells was significantly higher in MNCA than in MNT. There was no significant difference in the cell density of programmed death protein 1-positive T cells and programmed death ligand 1 expression between the MNT and MNCA cases. Our findings indicated that the immune microenvironment of MNCA differed from that of MNT and, compared with the T-cell profile of MNT, that of MNCA was more suppressive to patients′ antitumor immune response.     

Notch-Hes1 signaling activation in Caroli disease and polycystic liver disease

The Notch signaling pathway plays a key role in the morphogenesis of the biliary tree, but its involvement in cystic biliary diseases, such as Caroli disease (CD) and polycystic liver disease (PLD), has yet to be determined. Immunostaining was performed using liver sections of CD and PLD, and the results were compared with those of congenital hepatic fibrosis (CHF) and von Meyenburg complex (VMC). The expression of Notch receptor 1 (Notch1) was increased in the nuclei of biliary epithelial cells in all cases of CD and PLD, whereas it remained at a low level in CHF and VMC. In addition, Notch2 and Notch3 were preferably expressed in the nuclei of biliary epithelial cells of PLD. Accordingly, the Notch effector Hes1 was highly expressed in biliary epithelial cells of CD and PLD, and the cell proliferative activity was significantly higher in CD and PLD. The expression of the Notch ligand Delta-like 1 was significantly increased in biliary epithelial cells of CD and PLD, which may be causally associated with the nuclear overexpression of Notch1 and Hes1. These results indicate that aberrant activation of the Notch-Hes1 signaling pathway may be responsible for the progression of biliary cystogenesis in CD and PLD.     

Nontuberculous mycobacteria‐associated spindle cell pseudotumor of the nasal cavity: A case report

Mycobacterial spindle cell pseudotumor (MSP) is a rare mass‐forming lesion caused by mycobacterial infection, mostly in immunocompromised patients. Since it is composed of a proliferation of spindle‐shaped fibrohistiocytic cells without forming epithelioid cell granulomas, histological distinction from other spindle cell lesions is often difficult and its pathophysiology is poorly understood. MSP arising in the nasal cavity is extremely rare, and only two cases have been reported previously. Here we report a case of MSP of the nasal cavity in an 83‐year‐old man with no evidence of immunodeficient state. The resected tumor consisted of spindle cells, which contained numerous acid‐fast bacilli in the cytoplasm. By polymerase chain reaction and sequencing using DNA extracted from the paraffin sections, the bacilli were identified as Mycobacterium intracellulare. Immunohistochemistry revealed that the spindle cells were positive for CD68, CD11c and S100 protein, confirming the histiocytic nature of these cells. They were also positive for CD163 and CD204, suggesting that they showed a phenotype similar to alternatively activated (M2) macrophages and the phenotype might contribute to the maintenance of mycobacterial infection despite apparent immunocompetence of the host.     

Low contrast dose protocol involving a 100 kVp tube voltage for hypervascular hepatocellular carcinoma in patients with renal dysfunction

Purpose

To evaluate the feasibility of a 20 % reduced contrast dose hepatic arterial phase (HAP) CT for hypervascular hepatocellular carcinoma (HCC) with 100 kVp.

Materials and methods

The study included 97 patients with hypervascular HCC who underwent dynamic CT, including HAP scanning. The 54 patients had an estimated glomerular filtration rate (eGFR) of ≥60 were scanned with our conventional 120 kVp protocol. The other 43 patients (eGFR < 60) underwent scans using a tube voltage of 100 kVp and a 20 % reduced contrast dose. We compared the estimated effective dose, image noise, tumor-liver contrast (TLC), and contrast-to-noise ratio (CNR) in the hepatic arterial phase between the two groups using the Student’s t test.

Results

Estimated effective dose and image noise were not significantly different between these groups (p = 0.67 and p = 0.20, respectively). The TLC and CNR were significantly higher for the 100 kVp protocol than for the 120 kVp protocol (52.2 HU ± 17.4 vs 40.8 HU ± 18.6, p < 0.01 and 6.8 ± 2.6 vs 5.5 ± 2.4, p = 0.01, respectively).

Conclusion

For hepatic arterial phase CT of hypervascular HCC, 100 kVp scan allows a 20 % reduction in the contrast dose without reduction in image quality compared with a standard 120 kVp CT protocol.