Tumor-to-Tumor Metastasis of Medullary Thyroid Carcinoma to Paraganglioma in a Multiple Endocrine Neoplasia Type 2B Patient: A Case Report and Literature Review.

Tumor-to-tumor metastasis is a rare phenomenon in which primary tumor cells metastasize to other tumors. Herein, we report an extremely rare case of tumor-to-tumor metastasis of medullary thyroid carcinoma to a paraganglioma in a patient with multiple endocrine neoplasia type 2B. Based on genetic examination, a 36-year-old woman was diagnosed with multiple endocrine neoplasia type 2B when she was 24 years old. She had a history of total thyroidectomy for medullary thyroid carcinoma and bilateral adrenalectomy for pheochromocytomas, which were performed when she was 15 years and 29 years old, respectively. Follow-up computed tomography demonstrated a retroperitoneal tumor of 30 mm in diameter beside the left kidney and a liver tumor of 16 mm in diameter located in segment 6. The retroperitoneal and liver tumors were surgically resected and examined by a pathologist. Histological examination revealed the classic Zellballen pattern in the retroperitoneal tumor, rendering the diagnosis of a paraganglioma recurrence. Inside the tumor, a white nodule positive for carcinoembryonic antigen, weakly positive for calcitonin, and negative for tyrosine hydroxylase, was identified and diagnosed as a metastatic medullary thyroid carcinoma with high malignant potential. The liver lesion was diagnosed as a metastasis of the medullary thyroid carcinoma. This is the first report of tumor-to-tumor metastasis of medullary thyroid carcinoma to paraganglioma in a patient with multiple endocrine neoplasia type 2B twenty years after total thyroidectomy.

Ideal Duration of Pretreatment Using a Gelatin Hydrogel Nonwoven Fabric Prior to Subcutaneous Islet Transplantation.

Subcutaneous islet transplantation is a promising treatment for severe diabetes; however, poor engraftment hinders its prevalence. We previously revealed that a gelatin hydrogel nonwoven fabric (GHNF) markedly improved subcutaneous islet engraftment in comparison with intraportal islet transplantation. We herein investigated whether the duration of pretreatment using GHNF affected the outcome of subcutaneous islet transplantation. A silicone spacer with GHNF was implanted into the subcutaneous space of healthy mice at 2, 4, 6, or 8 weeks before transplantation, and then diabetes was induced 7 days before transplantation. Syngeneic islets were transplanted into the pretreated space. Blood glucose, intraperitoneal glucose tolerance, immunohistochemistry, inflammatory mediators, and gene expression were evaluated. The 6-week group showed significantly better blood glucose changes than the other groups (P < 0.05). The cure rate of the 6-week group (60.0%) was the highest among the groups (2-week = 0%, 4-week = 50.0%, 8-week = 15.4%). The number of von Willebrand factor (vWF)-positive vessels in the 6-week group was significantly higher than in the other groups at pre-islet and post-islet transplantation (P < 0.01 [vs 2-and 4-week groups] and P < 0.05 [vs all other groups], respectively). Notably, this beneficial effect was also observed when GHNF was implanted into diabetic mice injected with streptozotocin 7 days before GHNF implantation. The positive rates for laminin, collagen III, and collagen IV increased as the duration of pretreatment became longer and were significantly higher in the 8-week group (P < 0.01). Inflammatory mediators, including interleukin (IL)-1b, granulocyte colony-stimulating factor (G-CSF), and interferon (IFN)-γ, were gradually downregulated according to the duration of GHNF pretreatment and re-elevated in the 8-week group. Taken together, the duration of GHNF pretreatment apparently had an impact on the outcomes of subcutaneous islet transplantation, and 6 weeks appeared to be the ideal duration. Islet graft revascularization, extracellular matrix compensation of the islet capsule, and the inflammatory status at the subcutaneous space would be crucial factors for successful subcutaneous islet transplantation.

A gelatin hydrogel nonwoven fabric improves outcomes of subcutaneous islet transplantation.

Subcutaneous islet transplantation is a promising treatment for severe diabetes; however, poor engraftment hinders its prevalence. We previously reported that a recombinant peptide (RCP) enhances subcutaneous islet engraftment. However, it is impractical for clinical use because RCP must be removed when transplanting islets. We herein investigated whether a novel bioabsorbable gelatin hydrogel nonwoven fabric (GHNF) could improve subcutaneous islet engraftment. A silicon spacer with or without GHNF was implanted into the subcutaneous space of diabetic mice. Syngeneic islets were transplanted into the pretreated space or intraportally (Ipo group). Blood glucose, intraperitoneal glucose tolerance, immunohistochemistry, CT angiography and gene expression were evaluated. The cure rate and glucose tolerance of the GHNF group were significantly better than in the control and Ipo groups (p < 0.01, p < 0.05, respectively). In the GHNF group, a limited increase of vWF-positive vessels was detected in the islet capsule, whereas laminin (p < 0.05), collagen III and IV were considerably enhanced. TaqMan arrays revealed a significant upregulation of 19 target genes (including insulin-like growth factor-2) in the pretreated space. GHNF markedly improved the subcutaneous islet transplantation outcomes, likely due to ECM compensation and protection of islet function by various growth factors, rather than enhanced neovascularization.

A Gelatin Hydrogel Nonwoven Fabric Enhances Subcutaneous Islet Engraftment in Rats.

Although subcutaneous islet transplantation has many advantages, the subcutaneous space is poor in vessels and transplant efficiency is still low in animal models, except in mice. Subcutaneous islet transplantation using a two-step approach has been proposed, in which a favorable cavity is first prepared using various materials, followed by islet transplantation into the preformed cavity. We previously reported the efficacy of pretreatment using gelatin hydrogel nonwoven fabric (GHNF), and the length of the pretreatment period influenced the results in a mouse model. We investigated whether the preimplantation of GHNF could improve the subcutaneous islet transplantation outcomes in a rat model. GHNF sheets sandwiching a silicone spacer (GHNF group) and silicone spacers without GHNF sheets (control group) were implanted into the subcutaneous space of recipients three weeks before islet transplantation, and diabetes was induced seven days before islet transplantation. Syngeneic islets were transplanted into the space where the silicone spacer was removed. Blood glucose levels, glucose tolerance, immunohistochemistry, and neovascularization were evaluated. The GHNF group showed significantly better blood glucose changes than the control group (p < 0.01). The cure rate was significantly higher in the GHNF group (p < 0.05). The number of vWF-positive vessels was significantly higher in the GHNF group (p < 0.01), and lectin angiography showed the same tendency (p < 0.05). The expression of laminin and collagen III around the transplanted islets was also higher in the GHNF group (p < 0.01). GHNF pretreatment was effective in a rat model, and the main mechanisms might be neovascularization and compensation of the extracellular matrices.

Probable posttransplant lymphoproliferative disorder after pediatric living donor liver transplantation: Is a biopsy still needed?

Posttransplant lymphoproliferative disorder (PTLD) is a complication of solid organ transplantation and is associated with Epstein-Barr virus (EBV). Recently, EBV-related PTLD was defined as probable PTLD or proven PTLD. Probable PTLD involves significant lymphadenopathy, hepatosplenomegaly, or other end-organ manifestations, without a histological diagnosis, together with significant EBV DNAemia. Proven PTLD is the detection of EBV-encoded proteins in a tissue specimen, together with symptoms and/or signs originating from the affected organ. Probable PTLD after pediatric liver transplantation has not been well documented. Therefore, here, we aimed to describe cases of five pediatric patients with probable PTLD after liver transplantation, who were successfully treated with preemptive immunosuppression reduction with or without rituximab. All five patients (age range, 1-4 years; two girls and three boys) had EBV DNAemia. Three patients developed probable PTLD within 12 months of transplantation. Further, three patients had a significantly high EBV viral load, but the other two patients with lymphadenopathy and end-organ manifestation had a relatively low EBV viral load. Early onset pediatric PTLD with significant EBV DNAemia is almost universally EBV-related. Biopsy was not performed in any patient due to the relative inaccessibility of the lesion and young age of the patients. If the patient's symptoms are too mild, if excisional biopsy is too difficult to perform, or if the patient is too sick to undergo an invasive procedure, initiating preemptive treatment without a histological diagnosis could be the treatment option.

[A Case of Pancreatic Cancer That Was Radically Resected after Chemotherapy and Radiation Therapy, but Recurred Early and Followed a Rapid Course].

A 71-year-old man presented to our hospital with abdominal pain. He was diagnosed with acute pancreatitis and pancreatic cancer. Peritoneal washing cytology(CY)was positive, and laparotomy findings revealed severe inflammatory changes of pancreatitis, suggesting a high likelihood of the need for combined resection of other organs. Therefore, following the exploratory laparotomy, mFOLFIRINOX was initiated as chemotherapy. After 24 courses of mFOLFIRINOX, he developed drug-induced pneumonia. Therefore, chemotherapy was interrupted, and a steroid was started. Radiotherapy was administered during steroid tapering. There was no evidence of local progression or distant metastasis. A radical resection that included pancreaticoduodenectomy and right hemicolectomy was performed 23 months after the exploratory laparotomy. CY was negative and R0 resection was achieved. However, 5 months after the operation, he developed liver abscesses and cholangitis and was suspected to have liver metastasis. He underwent PTAD and PTCD, but died due to liver failure 8 months postoperatively. The early recurrence of this case might have been caused by the lack of postoperative chemotherapy due to his frailty. Surgical indications should be carefully judged if there is a high risk of recurrence after NAC and a high possibility that ACT cannot be performed after radical surgery.

KRP-203 Is a Desirable Immunomodulator for Islet Allotransplantation.

BACKGROUND: The current standard immunosuppressive regimens, calcineurin inhibitors, have diabetogenic and anti-vascularization effects on islet grafts. KRP-203, a sphingosine-1-phosphate functional antagonist, exerts its immunomodulatory function through lymphocyte sequestration. However, the effect of this antagonist on islets is unclear. We examined the effect of KRP-203 on the islet function and vascularization and sought a calcineurin-free regimen for islet allotransplantation. METHODS: KRP-203 was administered for 14 d to mice, then diabetogenic effect was evaluated by blood glucose levels and a glucose tolerance test. Static glucose stimulation, the breathing index, and insulin/DNA were examined using isolated islets. Islet neovascularization was evaluated using a multiphoton laser scanning microscope. After islet allotransplantation with either KRP-203 alone, sirolimus alone, or both in combination, the graft survival was evaluated by blood glucose levels and immunohistochemical analyses. A mixed lymphocyte reaction was also performed to investigate the immunologic characteristics of KRP-203 and sirolimus. RESULTS: No significant differences in the blood glucose levels or glucose tolerance were observed between the control and KRP-203 groups. Functional assays after islet isolation were also comparable. The multiphoton laser scanning microscope showed no inhibitory effect of KRP-203 on islet neovascularization. Although allogeneic rejection was effectively inhibited by KRP-203 monotherapy (44%), combination therapy prevented rejection in most transplanted mice (83%). CONCLUSIONS: KRP-203 is a desirable immunomodulator for islet transplantation because of the preservation of the endocrine function and lack of interference with islet neovascularization. The combination of KRP-203 with low-dose sirolimus may be promising as a calcineurin-free regimen for islet allotransplantation.

Novel technique for recanalization of severe hepaticojejunal obstruction using a transseptal needle in a pediatric liver transplant recipient.

BACKGROUND: Endoscopic and PTB interventions are common nonsurgical interventions for biliary anastomotic strictures that occur after liver transplantation. When these nonsurgical interventions fail, surgical re-anastomosis is considered; however, this is quite invasive and can cause additional injury that may lead to graft loss. We report a case in which conventional nonsurgical interventions failed, but a new method that involve the use of a transseptal needle-a device to create a transseptal left-heart access during cardiac catheter interventions-was successfully used in recanalization of the hepaticojejunal anastomotic obstruction. CASE: A 21-year-old man, who had received living-donor liver transplantation for biliary atresia at the age of 23 months presented with recurrent cholangitis and liver dysfunction due to a biliary anastomotic stricture of the hepaticojejunostomy. Therapeutic interventions for biliary stricture, including the PTB approach, double-balloon enteroscopic approach, and rendezvous approach failed. We then performed needle puncture of the anastomotic obstruction using a transseptal needle and succeeded in recanalizing the complete anastomotic obstruction. To perform the procedures safely, we evaluated the organ and needle positions using biplane fluoroscopy and placed a balloon in the afferent jejunal limb as a target for puncture. The 12 Fr catheter via the biliary route was removed 7 months after the procedure, without using a catheter, there was no recurrent stricture or cholangitis for 26 months. CONCLUSION: Using a transseptal needle to manage hepaticojejunal anastomotic obstruction can reduce the number of patients who need surgical re-anastomosis.

Living donor liver transplantation for Budd‒Chiari syndrome with right posterior segment graft and patch plasty using the superficial femoral vein: a case report.

BACKGROUND: In living donor liver transplantation (LDLT) for patients with Budd‒Chiari syndrome (BCS), there are several concerns about reconstruction of the inferior vena cava (IVC) and hepatic veins. Herein, we report the case of a patient with BCS who underwent LDLT with right posterior segment graft (RPSG) and patch plasty for reconstruction of the hepatic venous outflow, using the patient's own superficial femoral vein (SFV). CASE PRESENTATION: A 19-year-old man, who was diagnosed with primary BCS, underwent LDLT. His main hepatic veins were totally obstructed, and membranous stenosis was seen in the IVC. The LDLT donor was his mother; however, liver volumetric analysis showed that only her RPSG was appropriate. In the recipient surgery, 16 cm of the left SFV was harvested and was cut longitudinally and opened. The right hepatic vein (RHV) of the RPSG was anastomosed to the sidewall of the SFV graft. After explantation of native diseased liver was completed, the stenotic and thickened wall of the IVC was widely resected, and a large anastomotic orifice was created. Patch cavoplasty was performed with the RHV‒SFV graft patch. After portal reperfusion started, hepatic venous outflow was satisfactory, and there was no venous graft congestion. Both his postoperative course and his long-term course after discharge were uneventful. CONCLUSIONS: In LDLT for BCS patients, ingenuity is required for the reconstruction of venous outflow. The SFV patch can be safely harvested from liver transplant recipients and is suitable for venous reconstruction. In addition, RPSG is an alternative type of liver graft for LDLT if a conventional right- or left-lobe graft cannot be used.

Laparoscopic liver cyst fenestration with real-time indocyanine green fluorescence-guided surgery: a case report.

Laparoscopic fenestration (LF) has recently been considered a standard procedure for nonparasitic symptomatic liver cysts. Here, we report a case of LF that was safely performed using real-time indocyanine green (ICG) fluorescence-guided surgery. A 74-year-old woman presented with right upper abdominal pain and poor dietary intake. The patient was diagnosed with symptomatic liver cysts and underwent LF. One hour before surgery, ICG (2.5 mg) was intravenously administered to the patient. ICG fluorescence imaging clearly showed the biliary ducts and distinguished the cysts from the liver parenchyma. We could resect only the cyst walls as wide as possible under the guidance of both white light and fluorescence imaging. There were no signs of postoperative symptom recurrence. Detection of ICG fluorescence in the liver parenchyma is as important as ICG cholangiography for fenestration. Laparoscopic liver cyst fenestration with real-time ICG fluorescence-guided surgery is safe and can be used as a standard procedure.