A para-aortic malignant melanotic nerve sheath tumor mimicking a gastrointestinal stromal tumor: a rare case report and review of literature.

BACKGROUND: Malignant melanotic nerve sheath tumor (MMNST), formerly called melanotic schwannoma, is a rare tumor of neural crest derivation which most frequently arises from the region of spinal or autonomic nerves near the midline. Recent studies have reported malignant behavior of MMNST, and there still has no standard management guidelines. Intra-abdominal MMNST, which has never been reviewed as an entity, is even rarer. In this study, we present a rare case of a cystic MMNST arising from the para-aortic region and mimicking an intra-abdominal gastrointestinal stromal tumor (GIST), and review the literature regarding MMNSTs located in the abdominal cavity. CASE PRESENTATION: A 59-year-old female was incidentally found a tumor located in the left para-aortic area by non-contrast computed tomography. A Magnetic Resonance Imaging showed a cystic mass originated from the inferior mesenteric artery (IMA) territory. A GIST was initially diagnosed. The tumor was resected en bloc by laparoscopic surgery and was found between mesocolon and Gerota's fascia with blood supply of IMA. Grossly, dark brown materials were noted at the inner surface of the cystic wall. Microscopically, the tumor cells were melanin-containing, and no psammomatous bodies were present. Immunohistochemically, the tumor showed positivity for MART1, HMB45, collagen IV, and SOX10, and negativity for AE1/AE3. MMNST was favored over malignant melanoma, since the tumor was located near ganglia and had cells with less atypical cytology and a low mitotic rate, and subsequent adjuvant radiotherapy was performed. The patient was alive with no evidence of recurrent or metastatic disease 11 months after radiotherapy. CONCLUSIONS: Our review of abdominal MMNST cases showed a female predominance, with an average age of 54.8 years, and a trend toward being a larger tumor showing cystic or necrotic changes. Local recurrence and metastasis rate were reviewed, and both showed a low rate. Diagnosis of MMNST should combine all the available findings, and complete excision of the tumor should be performed, followed by long-term patient monitoring.

Reduced Expression of Metallothionein-I/II in Renal Proximal Tubules Is Associated with Advanced Chronic Kidney Disease.

Chronic kidney disease (CKD) is a commonly occurring complex renal syndrome that causes overall mortality in many diseases. The clinical manifestations of CKD include renal tubulointerstitial fibrosis and loss of renal function. Metallothionein-I/II (MT-I/II) is potentially expressed in the liver and kidney, and possesses antioxidant and metal detoxification properties. However, whether MT-I/II expression is associated with the prognosis of nephropathy remains unknown. In this study, we investigated the MT-I/II level in human CKD, using immunohistochemistry. MT-I/II is located on the proximal tubules and is notably reduced in patients with CKD. MT-I/II expression was significantly correlated with the functional and histological grades of CKD. In an aristolochic acid (AAI)-induced nephropathy mouse model, MT-I/II was abundantly increased after AAI injection for 7 days, but decreased subsequently compared to that induced in the acute phase when injected with AAI for 28 days. Furthermore, we found that ammonium pyrrolidinedithiocarbamate (PDTC) restored AAI-induced MT-I/II reduction in HK2 cells. The injection of PDTC ameliorated AAI-induced renal tubulointerstitial fibrosis and reduced the concentrations of blood urea nitrogen and creatinine in mouse sera. Taken together, our results indicate that MT-I/II reduction is associated with advanced CKD, and the retention of renal MT-I/II is a potential therapeutic strategy for CKD.

Expression of Nik-related kinase in smooth muscle cells attenuates vascular inflammation and intimal hyperplasia.

Inflammation of the vascular microenvironment modulates distinct types of vascular cells, and plays important roles in promoting atherosclerosis, stenosis/restenosis, and vascular-related diseases. Nik-related kinase (Nrk), a member of the Ste20-type kinase family, has been reported to be selectively expressed in embryonic skeletal muscle. However, whether Nrk is expressed in adult vascular smooth muscle, and if it influences intimal hyperplasia is unclear. Here, we found that Nrk is abundantly expressed in cultured vascular smooth muscle cells (VSMC) and mouse arterial intima. Treatment of mouse VSMCs with lipopolysaccharide (LPS) or platelet-derived growth factor significantly reduced Nrk expression. In addition, expression of Nrk was significantly reduced in regions of neointimal formation caused by guide-wire carotid artery injuries in mice, as well as in human atherosclerotic tissues, when compared to normal vessels. We identified that expression of matrix metalloproteinases (MMP3, MMP8 and MMP12) and inflammatory cytokines/chemokines (CCL6, CCL8, CCL11, CXCL1, CXCL3, CXCL5 and CXCL9) are synergistically induced by Nrk siRNA in LPS-treated mouse VSMCs. Moreover, we found that resveratrol significantly impaired LPS- and Nrk siRNA-induced expression of MMP3, CCL8, CCL11, CXCL3 and CXCL5. These results suggested that Nrk may play important roles in regulating pathological progression of atherosclerosis or neointimal- hyperplasia-related vascular diseases.

Masked pemphigus among pediatric patients with Castleman's disease.

AIM: Paraneoplastic pemphigus (PNP) is a mucocutaneous autoimmune disorder accompanied with a neoplasm. Castleman's disease (CD), although rare, is the most common cause of PNP in children. It can be life-threatening when pulmonary involvement occurs. Our study aimed to describe the features of PNP resulting from CD and to find clues for the early diagnosis in pediatric patients. METHOD: We report the case of a 13-year-old girl who initially presented with oral ulcers and lichen planus, with progression to respiratory failure. A literature review of PNP and CD in children between 1997 and 2016 was performed. The clinical manifestations, pathological findings, treatment, and outcome were analyzed. RESULTS: Thirty-two children were included in our study: 16 boys and 16 girls. Intractable mucocutaneous lesions developed early before CD was diagnosed. The clinical manifestations comprised oral ulcers (100%), polymorphous skin rash (86.7%) and genital (62.5%) erosion. Histopathological findings revealed lymphoplasmacytic cells infiltration (92%), vacuolar interface change (72%), acantholysis (68%), and keratinocytes necrosis (36%). Thirty patients underwent tumor resection. These patients mainly had unicentric CD, with the hyaline-vascular variant dominant. Twenty-six patients (81.2%) exhibited pulmonary involvement. The mortality rate was 70.0%. Among them, 90.5% exhibited pulmonary involvement, and 81.0% died of respiratory failure. CONCLUSION: Intractable mucocutaneous lesions with a concurrent tumor in children strongly indicate PNP resulting from CD. Because stomatitis or skin erosion may be the first presentation, mucocutaneous tissue biopsy and early detection of the underlying tumor are important. Earlier diagnosis is mandatory for the effective treatment of PNP and pulmonary involvement.

Can mixed pure hepatocellular carcinoma and germinoma arise together in the brain?

Intracranial germ-cell tumors (GCTs) represent 10-15% of all pediatric brain tumors in East Asia. There is a wide histopathological spectrum of intracranial GCTs. Germinomas and nongerminomatous GCTs are the two major classifications. It is difficult to distinguish different subtypes of intracranial GCTs based solely on imaging studies, however, some tumor markers, such as α-fetoprotein or ß-human chorionic gonadotropin, are helpful for diagnosis. In this study we present the case of a 13-year-old girl with an intracranial mixed GCT containing a hepatocellular carcinoma and germinoma without a primary liver tumor. Based on this unique pathological diagnosis, a series of treatments were applied, including surgery for gross tumor removal, adjuvant radiotherapy, and chemotherapy. Long-term follow up indicates fair disease control.