Risk classification system using the detailed positive surgical margin status for predicting biochemical recurrence after robot-assisted radical prostatectomy.

AIM: This study aimed to evaluate the risk classification system using the detailed positive surgical margin (PSM) status to predict biochemical recurrence (BCR) after robot-assisted radical prostatectomy (RARP). METHODS: We retrospectively analyzed 427 patients who underwent RARP between January 2016 and March 2020. We investigated risk factors for BCR using univariate and multivariate Cox proportional hazard regression models. The biochemical recurrence-free survival (BRFS) rate was assessed using the Kaplan-Meier method. RESULTS: The median follow-up period was 43.4 months and 99 patients developed BCR. In the multivariate analysis, maximum PSM length > 5.0 mm and the International Society of Urological Pathology grade group (ISUP GG) at the PSM ≥3 were predictive factors for BCR in patients with a PSM. In the multivariate analysis, these factors were also independent predictive factors in the overall study population, including patients without a PSM. We classified the patients into four groups using these factors and found that the 1-year BRFS rates in the negative surgical margin (NSM) group, low-risk group (PSM and neither factor), intermediate-risk group (either factor), and high-risk group (both factors) were 94.9%, 94.5%, 83.1%, and 52.9%, respectively. The low-risk group showed similar BRFS to the NSM group (p = 0.985), while the high-risk group had significantly worse BRFS than the other groups (p < 0.001). CONCLUSION: Maximum PSM length > 5.0 mm and ISUP GG at the PSM ≥3 were independent predictive factors for BCR after RARP. Risk classification for BCR using these factors is considered to be useful and might help urologists decide on additional treatment after RARP.

Distribution of osteoprotegerin in unruptured intracranial aneurysms in humans: association with aneurysm wall protective remodeling.

OBJECTIVE: Aneurysm wall inflammation is associated with lesion instability in unruptured intracranial aneurysms (UIAs). However, most UIAs remain unruptured during lifelong follow-ups because of simultaneous protective remodeling against the inflammatory response. The protective effects of osteoprotegerin (OPG) in intracranial and abdominal aortic aneurysms have been suggested using rodent models; however, the role of this protein in UIAs in humans remains unclear. Herein, the authors examined the relationship between OPG expression and aneurysm wall integrity in intraoperatively resected UIAs by using immunohistochemical and immunofluorescence staining. METHODS: Sixteen UIA wall tissue specimens resected between 2017 and 2022 were analyzed. Aneurysm growth was defined as an enlargement > 1 mm or an obvious morphological change over the course of more than 6 months. Three high-power fields were randomly selected from areas expressing high and low levels of OPG within the same aneurysm. To clarify the role of OPG in the human aneurysm wall, the authors compared averaged values for the following pathological features between the 2 OPG expression groups: aneurysm wall thickness, collagen, macrophages, smooth muscle cells, and transforming growth factor beta 1 (TGF-ß1). Immunohistochemical staining within the entire tissue area was also analyzed to determine the relationships between OPG expression and different aneurysm growth patterns. Pathological findings were compared between high and low OPG expression levels using the Wilcoxon signed-rank test. RESULTS: The heterogeneous expression of OPG was detected in the walls of UIAs. Lesions expressing high OPG levels had thicker aneurysm walls (327 vs 180 µm, p = 0.002) and higher expression levels of TGF-ß1 (8.5% vs 5.4%, p = 0.002) than those expressing low OPG levels. The expression of TGF-ß1 was colocalized with that of OPG mainly in the tunica media. Furthermore, lesions expressing high OPG levels had larger α-SMA+ areas (25% vs 13%, p = 0.002). Aneurysm growth was observed in 6 of 9 UIAs with available data: whole sac expansion in 4 and secondary aneurysm formation in 2. Among the 6 UIAs with aneurysm growth, OPG expression was relatively higher in the UIAs with an internal elastic lamina than in those without (17% vs 6.9%). CONCLUSIONS: Aneurysm wall integrity was associated with OPG expression in the aneurysm wall. Collectively, the study results indicated that OPG is associated with protective remodeling, which may contribute to the retention of aneurysm wall structures.

Dual-energy Computed Tomography Iodine Map for Breast Cancer: Comparison With Dynamic Contrast-enhanced Magnetic Resonance Imaging.

BACKGROUND/AIM: The characteristics of different breast cancers imaged using dual-energy computed tomography (DECT) are unknown. Furthermore, the differences between DECT and magnetic resonance imaging (MRI) in the ability to assess tumor extent have not been clarified. Therefore, this study aimed to evaluate the effectiveness of DECT iodine maps compared to contrast-enhanced MRI in patients with operable breast cancer. PATIENTS AND METHODS: Clinicopathological data from 858 patients with breast cancer who underwent resection after DECT (100/140 kv) and MRI during 2012-2021 were collected. Tumoral iodine concentration (IC; max/Δ) was analyzed from iodine maps. Factors associated with the ability of iodine maps and MRI to predict tumor extent were analyzed with reference to resected specimens' pathological diagnosis. RESULTS: IC parameters varied according to the tumors' histological types and were correlated with the estrogen receptor, histological grade, and Ki-67 labeling index. In 86.2% of patients with invasive carcinoma with intraductal extension, images and resected specimen mapping were matched. Iodine maps were less accurate than MRI in identifying tumor borders in 9.8% and more accurate in 2.1% of patients. The discrepancies in assessing tumor borders between imaging modalities were associated with the tumor's IC parameters and mammary gland status. CONCLUSION: Differences in assessment between DECT and MRI in operable breast cancer are associated with IC parameters and background parenchymal enhancement. Therefore, evaluating tumor extent using DECT considering these characteristics appears to be a feasible approach.

Ischemic Necrosis of the Gastric Remnant Treated Successfully Using Total Remnant Gastrectomy.

Distal gastrectomy (DG) with lymph node dissection is considered as the standard treatment for gastric cancer. Ischemic necrosis of the gastric remnant is a rare but serious complication of DG that requires careful consideration for early diagnosis and treatment to lower the associated mortality rate. A 71-year-old male presented to our hospital with hyperglycemia and was evaluated for suspected diabetes. The patient's medical history was otherwise unremarkable. Computed tomography (CT) revealed a thickening of the stomach wall, with follow-up esophagogastroduodenoscopy revealing type 3 gastric cancer in the greater curvature of the antrum. Biopsy specimen confirmed a pathological diagnosis of mucinous adenocarcinoma, with a clinical diagnosis of cT3N0M0, cStageIIB. An open DG with Billroth I reconstruction was performed, without incident. On postoperative day 1, the patient developed a high fever, abdominal pain, and elevated white blood cell count (12,200/µL). On postoperative day 2, his C-reactive protein level increased to >30 mg/dL. CT revealed an edematous thickening of the stomach wall, with poor mucosal enhancement of the remnant stomach and thinning of the anastomosis wall, with air nearby. Emergency surgery was performed for suspected leakage. Intraoperative findings showed no evidence of leakage. Intraoperative endoscopy revealed a necrotic gastric remnant, and we performed a total remnant gastrectomy with Roux-en Y reconstruction. The patient was discharged in a stable condition, 25 days after the first surgery. Although ischemic necrosis of the gastric remnant is a rare complication, its possibility should be carefully considered after DG, for early diagnosis and treatment.

Squamous Metaplasia of the Colon Following Severe COVID-19.

A 53-year-old man was admitted for respiratory failure due to severe acute respiratory syndrome caused by a severe acute respiratory syndrome coronavirus 2 infection. The patient required prolonged artificial ventilation and extracorporeal membrane oxygenation (ECMO) for respiratory support. Despite successful discontinuation of ECMO, the patient experienced profuse watery diarrhea (5-10 L/day). A colonoscopy revealed an inflamed surface without undulation that uniformly extended throughout the colon. Biopsy specimens revealed complete disappearance of existing crypts and replacement with squamous or transitional epithelium normally observed in the anal transitional zone mucosa, with granulation tissue proliferation in the lamina propria. Watery diarrhea persisted despite corticosteroid and infliximab administration. Although diarrhea due to atrophy of the surface and cryptic epithelium as an intestinal manifestation of coronavirus disease 2019 usually responds to corticosteroids, refractory diarrhea can be attributed to squamous metaplasia with complete disappearance of the surface and cryptic epithelium.

Association of Neutrophil Extracellular Traps with Plaque Instability in Patient with Carotid Artery Stenosis.

BACKGROUND: Vulnerable carotid plaques are related to cerebral thromboembolic and ischemic events. Neutrophil extracellular traps (NETs) can induce endothelial dysfunction and induce inflammation and coagulation. The aim of the present study was to investigate NETs in patients with carotid artery plaques. METHODS: Carotid plaques were collected by carotid endarterectomy (CEA) from 26 symptomatic and 8 asymptomatic patients between August 2017 and January 2021. The specimens were stained with hematoxylin-eosin and Elastica-van Gieson. Immunohistochemistry was performed staining by CD31 for identifying endothelial cells. NETs were detected by digoxigenin-labeled antihistone H3 (HH3) (citrulline R2+R8+R17). The relationships between the presence of NETs and patient profile and histopathological findings were assessed. RESULTS: HH3-positive cells were detected in 17 (asymptomatic = 2 symptomatic = 15) of 34 carotid plaques (median = 9.7/mm). The number of NETs was correlated with the number of diffusion-weighted imaging high-intensity lesions [P = 0.01], plaque rupture [P = 0.001], intraplaque hemorrhage [P = 0.02], intra luminal thrombus [P = 0.001], and thin fibrous cap [P = 0.001]. CONCLUSIONS: The presence of NETs was associated with the instability of carotid plaques, intraluminal thrombus, which may lead to subsequent cerebral infarction. Clarifying the roles of NETs in carotid plaques may improve the treatment of carotid artery disease.

Pancreatic duct rupture associated with high-grade pancreatic intraepithelial neoplasia treated by radical resection: a case report.

We here report a case of pancreatic duct rupture associated with high-grade pancreatic intraepithelial neoplasia treated by radical resection. A 71-year-old man presented to our hospital because of abdominal bloating. Diagnoses of early-stage pancreatic body cancer with pancreatic duct rupture, pancreatic ascites, and formation of a pseudocyst were made on the basis of blood tests, multidetector dynamic computed tomography, endoscopic ultrasonography, magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography. After achieving control of the ascites by placement of a pancreatic duct stent and aspiration of the pseudocyst, distal pancreatectomy with D2 lymph node dissection was performed. Intraoperative cytologic examination of the ascites was negative. The pathological diagnosis was high-grade pancreatic intraepithelial neoplasia in the pancreatic body. The branched pancreatic duct was occluded and dilated by acute inflammation around the pancreatic neoplasm, the inflammation being in the region of the dilated branched pancreatic duct and having caused its rupture. To the best of our knowledge, this is the first published report of pancreatic duct rupture associated with high-grade pancreatic intraepithelial neoplasia.

Clinical Behavior of Combined Versus Pure High-Grade Neuroendocrine Carcinoma.

BACKGROUND: The aim of this study was to investigate and compare the clinical behaviors of combined and pure high-grade neuroendocrine carcinoma (large-cell neuroendocrine carcinoma [LCNEC] and small-cell lung carcinoma [SCLC]). PATIENTS AND METHODS: Data of 132 patients who underwent complete resection for combined or pure high-grade neuroendocrine carcinoma (combined group, 67; pure group, 65) between January 2001 and December 2015 were retrospectively reviewed. The clinicopathological features were analyzed and compared, and the prognoses were assessed by performing the Kaplan-Meier method and Cox regression analysis. RESULTS: The combined and pure groups had nearly equivalent clinicopathological characteristics, specifically, older males with smoking history, almost the same percentage of pleural/lymphatic/vascular invasion, and nearly the same recurrence rates and relapse patterns. The combined group had prognosis equivalent to that of the pure group (5-year overall survival [OS] rates: 61.8% vs. 52.2%, respectively; P = .82 and 5-year recurrence-free survival [RFS] rates: 42.4% vs. 43.9%, respectively; P = .96), and this trend was identified in sub-analyses only for patients with LCNEC, SCLC, and the same pathological stage. Multivariable Cox regression analysis in patients with high-grade neuroendocrine carcinoma revealed that vascular invasion and pathological stage were independent prognostic factors for OS; more importantly, combined and pure histologies were proven to have nearly equivalent associations with prognosis (hazard ratio, 0.96; 95% confidence interval, 0.22to 1.66; P = .96). RESULTS: Combined high-grade neuroendocrine carcinoma had clinical behavior equivalent to those of pure high-grade neuroendocrine carcinoma, with similar clinicopathological characteristics.

CD44 Is Involved in Sunitinib Resistance and Poor Progression-free Survival After Sunitinib Treatment of Renal Cell Carcinoma.

BACKGROUND/AIM: Sunitinib continues to be administered as a first-line therapeutic agent in metastatic renal cell carcinoma (mRCC). This study aimed to examine the role of CD44 in sunitinib resistance and as a predictive marker in mRCC. MATERIALS AND METHODS: We analyzed the effect of CD44 knockdown on sunitinib resistance in RCC cell lines using WST-1 assays. CD44 expression in mRCC patients treated with first-line sunitinib was determined by immunohistochemistry. We validated the findings of this study by in silico analysis. RESULTS: CD44 knockdown increased sensitivity to sunitinib. Immunohistochemical analysis revealed that 19 (34.5%) of 55 mRCC cases were positive for CD44. CD44-positive cases were associated with poor progression-free survival (PFS) after first-line sunitinib treatment. In the JAVELIN 101 study, high CD44 expression was significantly associated with poor PFS after sunitinib but not after avelumab + axitinib therapy. CONCLUSION: CD44 is involved in sunitinib resistance and may be a promising marker for sunitinib treatment in mRCC.

P53 Is Involved in Sunitinib Resistance and Poor Progression-free Survival After Sunitinib Treatment of Renal Cell Carcinoma.

BACKGROUND/AIM: Sunitinib continues to be administered as a first-line therapeutic agent in metastatic renal cell carcinoma (mRCC). This study examined the potential role of p53 in sunitinib resistance and as a predictive marker in mRCC. MATERIALS AND METHODS: We analysed the effects of p53 knockout on sunitinib resistance. p53 expression in 53 mRCC patients receiving first-line sunitinib was determined immunohistochemically. We performed in silico analysis to examine the predictive value of p53 in mRCC. RESULTS: WST-1 assays showed that p53 knockout decreased sensitivity to sunitinib. Sunitinib and nutlin-3 together suppressed cell growth. Immunohistochemistry revealed 11 p53-positive cases among 53 patients with mRCC. Kaplan-Meier analysis showed that p53-positive cases tended to be associated with poor progression-free survival (PFS) after first-line sunitinib treatment. In the JAVELIN 101 study, TP53 mutation was significantly associated with poor PFS after sunitinib treatment. CONCLUSION: p53 may be involved in sunitinib resistance and represent a valuable marker for sunitinib treatment in mRCC.

Pyogenic Granuloma Mimicking T1 Colorectal Carcinoma.

Pyogenic granuloma (PG), a benign capillary hemangioma, is extremely rare in the colon. Here, we present a case of PG that was difficult to distinguish from T1 (deep submucosal invasive) colorectal carcinoma. A 57-year-old woman with no remarkable history was referred to us for a detailed investigation of a positive fecal occult blood test. Colonoscopy revealed a reddish, irregular-shaped, protruding lesion (5 mm) in the rectum. We performed endoscopic mucosal resection of the lesion as total excisional biopsy because T1 colorectal carcinoma was suspected, despite the lesion's small size after observation by magnifying endoscopy. Histologically, the protruding lesion mainly consisted of numerous capillaries lined with plump and flat endothelial cells without signs of malignancy. Colorectal carcinoma, on the other hand, is composed of tall columnar atypical epithelial cells showing neoplastic proliferation. Thus, cell morphology is completely different between PG and colorectal carcinoma. The final diagnosis was colonic PG with a negative vertical margin. In conclusion, physicians should be aware of a colorectal protruding lesion devoid of malignant potential, as in this case, where the lesion was difficult to diagnose accurately and to distinguish from T1 colorectal carcinoma on magnifying endoscopy. Physicians should consider PG as a differential diagnosis in similar cases.

Clinical significance of immunohistochemical lymphovascular evaluation to determine additional surgery after endoscopic submucosal dissection for colorectal T1 carcinoma.

PURPOSE: The Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines indicate lymphovascular invasion-evaluated by hematoxylin and eosin (HE) staining-as a surgical requirement after endoscopic submucosal dissection (ESD) in T1 colorectal carcinoma (CRC) patients; however, immunohistochemical evaluation may be superior. This study aimed to clarify the significance of immunohistochemical lymphovascular evaluation as an indicator for additional surgery of T1 CRC after ESD, and assessed the guidelines' adequacy, even when evaluating through immunostaining. METHODS: Patients with T1 CRC who underwent ESD were enrolled across three institutions between January 2012 and December 2017. Immunohistochemical lymphovascular evaluation was performed. Clinicopathological features, pathological evaluations, and surgery indications were recorded. Univariate and multivariate logistic regression identified risk factors for lymph node (LN) metastasis of T1 CRC after ESD. RESULTS: Among 370 patients with T1 CRC, recurrence, 5-year overall survival, and 5-year disease specific survival rates were 1.6%, 94.6%, and 99.5%, respectively. Six patients (1.6%) experienced recurrence, five of whom underwent additional surgery. Those with no risk factors did not exhibit recurrence. A total of 215 (58.1%) patients underwent additional surgery after ESD, 21 (9.7%) of whom exhibited LN metastasis. Among 16 patients who underwent additional surgery due to lymphovascular invasion, three (18.8%) had LN metastasis. Multivariate logistic regression analysis identified lymphatic invasion as a significant risk factor for LN metastasis (odds ratio 3.9, 95% confidence interval 1.0-14.6, P = 0.0421). CONCLUSIONS: The JSCCR guidelines have clinical validity, and immunohistochemical lymphatic evaluation findings potentially predict LN metastasis for T1 CRC after ESD.

Laparoscopic anterior resection for rectal stenosis caused by ALTA injection for internal hemorrhoids: A case report.

We herein report the first case of rectal stenosis that developed after internal hemorrhoid treatment with aluminum potassium sulfate and tannic acid (ALTA) therapy that was successfully treated by laparoscopic surgery. A 72-year-old man suffered from a fever and rectal stenosis after undergoing internal hemorrhoid treatment with a submucosal injection of ALTA at a previous clinic. Three months after ALTA therapy, he developed frequent mucous and bloody stools. Lower intestinal tract endoscopy revealed circumferential severe rectal stenosis. He was therefore referred to our hospital. The patient suffered from frequent stool build-up and difficulty defecating. We performed balloon-dilatation intervention. The stenosis was not improved at all. Five months after ALTA therapy, we performed laparoscopic low anterior resection with diverting ileostomy. Three months after the operation, ileostomy takedown was performed. The patient has experienced no rectal stenosis in the 2 years since his radical operation.

Bone regeneration utilizing a newly developed octacalcium phosphate/weakly denatured collagen scaffold.

INTRODUCTION: Autologous bone grafting or various bone-regenerating materials are used to treat bone defects caused by tumor resection and accident trauma. Octacalcium phosphate, a reasonable bone regenerative material, activates osteoblasts. We fabricated a composite material, octacalcium phosphate/weakly denatured collagen, as a new scaffold. We aimed to investigate the osteoregenerative effect of the octacalcium phosphate/weakly denatured collagen scaffold (compared with that of weakly denatured collagen) in skull defects in a canine model. METHODS: Atelocollagen was extracted from porcine skin via pepsin treatment. The weakly denatured collagen scaffold was fabricated with a freeze-dried and thermally crosslinked atelocollagen suspension at pH 7.4. Octacalcium phosphate was synthesized using Ca-acetate and NaH2PO4. Octacalcium phosphate particles (diameter, 199-298 µm) were mixed with a collagen matrix to fabricate an octacalcium phosphate/weakly denatured collagen scaffold. Bilateral defects (diameter, 10 mm; full-thickness) were induced in dog skulls, and the octacalcium phosphate/weakly denatured collagen and weakly denatured collagen scaffolds were implanted into the defects. RESULTS: Eight weeks after implantations, bone regeneration was evaluated via histopathological analysis. It revealed osteoblast infiltration and osteoregeneration in all defects treated with the octacalcium phosphate/weakly denatured collagen scaffold. The defects treated with weakly denatured collagen scaffold or without any scaffold mostly contained connective tissue, with no neo-osteogenesis. DISCUSSION: The novel octacalcium phosphate/weakly denatured collagen scaffold better promotes osteoregeneration than the weakly denatured collagen scaffold; this "in situ tissue engineering" approach is potentially clinically applicable for bone reconstruction.

Gastrectomy for invasive micropapillary carcinoma is associated with poorer disease-free and disease-specific survival.

BACKGROUND: Invasive micropapillary carcinoma (IMPC) is a relatively rare subtype of gastric adenocarcinoma and has aggressive histopathologic characteristics, including lymphatic and vascular invasion. However, the associated long-term survival outcomes remain unclear. This study aimed to compare the clinicopathological characteristics and prognosis of gastric adenocarcinoma with and without IMPC using propensity score-matched (PSM) analysis. METHODS: Patients with gastric adenocarcinoma who underwent gastrectomy between 2006 and 2015 were included in the analysis. PSM analysis was performed to compensate for the background heterogeneity between the groups. The primary endpoint was disease-free survival (DFS) after gastrectomy, and the secondary endpoints were disease-specific survival (DSS) and recurrence pattern. RESULTS: Of 882 patients who underwent gastrectomy for gastric adenocarcinoma, with a follow-up duration greater than 36 months, 35 were diagnosed as having gastric adenocarcinoma with IMPC. After PSM, 70 patients, including 35 with IMPC and 35 without IMPC, were selected. Gastric adenocarcinoma with IMPC is characterized by lymphatic invasion (94% versus 69%, p = 0.012). Patients with IMPC had significantly poorer DFS than those without IMPC, with 3-year DFS rates of 62.2% and 93.4% (p = 0.003), respectively. Furthermore, a significant difference was also observed in DSS (p = 0.016); patients with IMPC more frequently developed liver metastasis (20%) than those without IMPC (3%, p = 0.006). CONCLUSIONS: Resected gastric carcinoma with IMPC was associated with poorer DFS and DSS; furthermore, an increased rate of lymphatic invasion and liver metastasis was noted than in cases without IMPC.

[A Case of Primary Small Cell Carcinoma in the Breast with Neoadjuvant Chemotherapy That Were Difficult to Select Chemotherapy].

Primary small cell carcinoma in the breast is a rare and aggressive tumor, and a standard treatment strategy has not been established. Herein, we report a 35-year-old woman with primary small cell carcinoma in the breast. She had an 8 cm diameter tumor in the right breast. She was diagnosed with small cell carcinoma(cT3N1M0, cStage ⅢA)in the right breast, and neoadjuvant chemotherapy was planned. She received a combination chemotherapy of cisplatin(CDDP)and etoposide(VP- 16)based on the regimen for pulmonary small cell carcinoma; however, the disease showed progression. Therefore, 5-FU plus epirubicin plus cyclophosphamide(FEC)and weekly paclitaxel(PTX)chemotherapy based on a regimen for breast cancer were administered, and the tumor was partially reduced in size. Modified radical mastectomy followed by radiotherapy and hormonal therapy was performed. Ten months after the surgery, multiple liver and bone metastases occurred, and the patient died the following month. Further studies in other such patients are needed.

Management and risk factors for incomplete resection associated with jumbo forceps polypectomy for diminutive colorectal polyps: a single-institution retrospective study.

BACKGROUND: Cold forceps polypectomy is simple and widely used in clinical practice. However, there are concerns about the risk of incomplete resection using this technique. In recent years, it has been reported that polypectomy with jumbo forceps (JF) is an effective treatment modality for diminutive polyps (DPs) because JF are able to remove large tissue samples with the combined advantage of a higher complete histological resection rate for DPs than standard forceps. To our knowledge, no studies have evaluated the risk factors for incomplete resection when polypectomy with JF is performed for DPs. METHODS: From among 1129 DPs resected using JF at Hiroshima City Asa Citizens Hospital between November 2015 and December 2016, we retrospectively evaluated the clinical outcomes of 999 tumors with known histopathology and investigated the relationship between incomplete resection and clinicopathological factors. RESULTS: Most lesions [985 (87%)] were low-grade dysplasia and 14 (1%) were high-grade dysplasia. The en bloc resection rate was 92% (918/999) and the histological en bloc resection rate was 78% (777/999). Multivariate analysis showed that the significant independent predictors of incomplete resection were tumor size ≥ 4 mm [odds ratio (OR) 3.8; 95% confidence interval (CI) 2.65-5.37; p < 0.01], non-tangential direction of forceps in relation to the tumor (OR 1.73; 95% CI 1.21-2.45; p < 0.01), and lack of muscularis mucosae in the pathological specimen (OR 15.7; 95% CI 9.16-27.7; p < 0.01). CONCLUSIONS: This study identified significant independent predictors of incomplete resection of DPs which may be helpful when planning polypectomy with JF.

Laparoscopic excision of a retroperitoneal schwannoma: A case report.

Schwannomas are tumors originating from the Schwann cells of the peripheral nerve sheath. Only 1%-3% of schwannomas reportedly occur in the pelvis. In a 67-year-old man, a pelvic mass that was 52 mm in diameter was incidentally diagnosed during a preoperative CT evaluation for prostate cancer. Preoperative 3-D reconstruction CT showed that the feeding artery to the tumor originated from the internal iliac artery and the drainage vein from the internal iliac vein. Each vessel could be isolated, clipped, and cut with minimal bleeding. The tumor was easily dissected from adjacent structures and was completely resected via laparoscopic surgery. Histopathology and immunohistochemistry of the excised specimen revealed a benign schwannoma. Using 3-D reconstruction to recognize a tumor's positional relation with the supplying vessels is important for avoiding complications during laparoscopic resection in the narrow pelvis. Laparoscopic resection is safe, feasible, and effective for retroperitoneal schwannoma.