Viral entry and translation in brain endothelia provoke influenza-associated encephalopathy.

Influenza-associated encephalopathy (IAE) is extremely acute in onset, with high lethality and morbidity within a few days, while the direct pathogenesis by influenza virus in this acute phase in the brain is largely unknown. Here we show that influenza virus enters into the cerebral endothelium and thereby induces IAE. Three-weeks-old young mice were inoculated with influenza A virus (IAV). Physical and neurological scores were recorded and temporal-spatial analyses of histopathology and viral studies were performed up to 72 h post inoculation. Histopathological examinations were also performed using IAE human autopsy brains. Viral infection, proliferation and pathogenesis were analyzed in cell lines of endothelium and astrocyte. The effects of anti-influenza viral drugs were tested in the cell lines and animal models. Upon intravenous inoculation of IAV in mice, the mice developed encephalopathy with brain edema and pathological lesions represented by micro bleeding and injured astrocytic process (clasmatodendrosis) within 72 h. Histologically, massive deposits of viral nucleoprotein were observed as early as 24 h post infection in the brain endothelial cells of mouse models and the IAE patients. IAV inoculated endothelial cell lines showed deposition of viral proteins and provoked cell death, while IAV scarcely amplified. Inhibition of viral transcription and translation suppressed the endothelial cell death and the lethality of mouse models. These data suggest that the onset of encephalopathy should be induced by cerebral endothelial infection with IAV. Thus, IAV entry into the endothelium, and transcription and/or translation of viral RNA, but not viral proliferation, should be the key pathogenesis of IAE.

A Case of Cardiac Undifferentiated Pleomorphic Sarcoma With Right Ventricular Outflow Tract Obstruction.

Malignant tumors originating from the heart are extremely rare. Here, we report a case of severe right ventricular outflow tract (RVOT) stenosis in a 67 year-old woman caused by a massive intimal sarcoma that required venous-arterial extracorporeal membrane oxygenation to support systemic circulation. Surgical resection and RVOT reconstruction with tricuspid and pulmonary valve replacement were performed. The pathological diagnosis was cardiac undifferentiated pleomorphic sarcoma. Although the patient was discharged 65 days after surgery in good condition, she subsequently died from multiple metastases detected in the early phase after surgery.

[A Case of Metastatic Liver Tumor from Colon Cancer with Preoperative Diagnosis Obtained by Immunohistochemical Analysis of Cytologic Specimen].

CASE: A woman in her 50s underwent sigmoid colectomy and D3 lymph node dissection for sigmoid cancer(pT3, N0, M0, Stage Ⅱ: Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma 9th). She received adjuvant chemotherapy with capecitabine. Seven months after surgery, contrast-enhanced computed tomography( CECT) scan revealed a small mass in the segment 2 (S2) of the liver with dilation of peripheral intrahepatic bile duct, and the size of this mass and the bile duct dilatation were gradually increased. FDG positron emission tomography(FDG-PET)/CT showed abnormal FDG uptakes in the lesion of S2, and EOB-MRI detected other small lesions in the S6 and S7. Considering the results of image examinations, multiple lesions intrahepatic cholangiocarcinoma was firstly assumed. However, immunohistochemistry of the tumor obtained by endoscopic retrograde cholangiopancreatography (ERCP) showed cytokeratin 7-negative. Based on preoperative diagnosis of liver metastasis from colon cancer rather than intrahepatic cholangiocarcinoma, we performed left lobectomy, partial hepatectomy of S6 and S7 and cholecystectomy. In the resected specimen, the tumor was macroscopically located in the intrahepatic bile ducts. Microscopically, there existed atypical epithelial cells with glandular duct-like structure, and the lesions was histopathologically diagnosed as metastasis from colon cancer. She was discharged on the 10th postoperative day, and she is alive without recurrence one year after surgery.

[A Case of Signet-Ring Cell Carcinoma of the Ampulla of Vater in a Young Male].

A male in his twentieth was referred to our hospital for jaundice. Computed tomography(CT)showed dilation of the intrahepatic and extrahepatic bile ducts and showed a lesion at the ampulla of Vater, which caused obstructive jaundice. Upper gastrointestinal endoscopy revealed a tumor of protruded-predominant type with raised margins at the ampulla of Vater, and biopsy from the lesion indicated malignancy. With no apparent distant metastasis, radical resection was assumed to be possible, thus we performed subtotal stomach preserved pancreatoduodenectomy. Before the operation, endoscopic retrograde biliary drainage(ERBD)was unsuccessful because of the existence of the tumor, so percutaneous transhepatic cholangio drainage(PTCD)was conducted. After the operation, although pancreatic fistula(ISGPF Grade B)occurred, it improved with conservative treatment, and he discharged at 30 postoperative days. Histopathological examination revealed signet-ring cell carcinoma among the tumor at the ampulla of Vater, which was infiltrating into the pancreas. Final diagnosis was pT3, pN0, M0, pStage ⅡA. Now he is alive without recurrence for 3 and a half years.

[A Case of Undifferentiated Carcinoma of Gallbladder with Five Year Recurrence-Free Survival after Radical Resection].

A woman in her 60s realized heart palpitations and was pointed out anemia. CT revealed a tumor measuring 7 cm, with internal necrosis, originating from the gallbladder and invading the liver, and diagnosed as gallbladder cancer. There existed no distant metastasis and we performed cholecystectomy with partial resection of segment 4a+5 of the liver and lymph node resection. Histopathological examination revealed highly atypical cells with large nuclei and polynuclear cells and poor cell junctions in the specimen, and the tumor was histologically diagnosed as an undifferentiated carcinoma. Metastases were not detected in dissected lymph nodes, and this case was diagnosed as undifferentiated carcinoma of gallbladder, T3a, N0, M0, Stage ⅢA(JSHBPS 6th). She was discharged at 13 days after the operation with no apparent postoperative complications. Postoperative adjuvant chemotherapy with administration of TS-1 was conducted for half a year. Now over 5 years have passed since the operation, and she is alive without recurrence.

[A Case of Squamous Cell Cancer of the Anus Treated with Chemoradiotherapy].

BACKGROUND: In Japan, the standard treatment for squamous cell anal cancer(SCAC)has not been established. Herein, we report a case of SCAC that completely responded to chemoradiotherapy(CRT). CASE: A woman in her 80s presented with anal pain and bleeding. Computed tomography revealed bilateral inguinal adenopathy and a tumor in the anal canal. Histopathological examination of endoscopic biopsies showed adenocarcinoma. Thus, she was diagnosed with anal canal adenocarcinoma and lymph node metastases:cT3, cN1a(No. 292), cM0, cStage Ⅲc(Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, 9th edition). Owing to her advanced age and refusal of a stoma, CRT(S-1, mitomycin C, and radiotherapy)was administered with the expectation that salvage surgery in the form of rectal amputation would eventually be necessary. The tumor noticeably shrank after CRT. The patient is alive to this date,14 months after the final round of CRT.

[A Case of Metastasis to the Pancreas from Colorectal Cancer Which Was Difficult to Distinguish from Primary Pancreatic Cancer].

A man in his 50s underwent laparoscopic sigmoid colectomy for sigmoid colon cancer with liver metastasis(cT4aN1M1a, cStage Ⅳa), followed by partial liver resection(S4, S6). One and a half years after the initial surgery, CEA and CA19-9 increased, and contrast-enhanced CT and MRI showed a hypovascular lesion with dilation of the distal pancreatic duct in the pancreatic body. Adenocarcinoma was detected by brushing cytology of the lesion and pancreatic juice cytology by ERCP. From the results of various examinations, the lesion was diagnosed as pancreatic ductal adenocarcinoma. We performed distal pancreatectomy, and initially the histopathological diagnosis was pancreatic body cancer(pT3N1aM0, pStage ⅡB). In a follow-up CT after surgery, a suspected metastatic lymph node was pointed out in the mediastinum, but it was difficult to distinguish between metastasis from colorectal cancer and one from pancreatic cancer. Immunostaining of the tumor tissue and comparative study of the excised specimens of colon and pancreas was performed in order to assume the primary lesion of the lymph node. As a result, both tissues were CK7(-)/CK20(+), and the lesion at first considered to be primary pancreatic cancer was originally the pancreatic metastasis from colon cancer. Bone metastases were also found on FDG-PET/CT around the same time, and then systemic chemotherapy for colorectal cancer was introduced. Four and a half years have passed since the first surgery, and he is still alive and undergoing treatment.

[A Case of Unresectable Liver Metastasis from Rectal Cancer Treated with Conversion Therapy].

We reported a case of rectal cancer with unresectable liver metastases treated with resection of the primary lesion followed by systemic chemotherapy with curative resection. A woman in her 40s was diagnosed with rectal RS carcinoma and unresectable liver metastasis, mFOLFOX6 plus panitumumab therapy was initiated after laparoscopic high anterior resection of the rectal lesion. After 5 courses of chemotherapy, significant shrinkage of the liver metastatic lesion and increase of the remnant liver volume were observed. Percutaneous transhepatic portal vein embolization( PTPE) was performed with the aim of further preserving remnant liver volume. Since the hepatic reserve was sufficient, the treatment strategy was to perform radical hepatectomy. Extended right hepatic lobectomy, S4 partial resection, and cholecystectomy were performed. The patient didn't relapse at 11 months after hepatectomy.

Thrombotic thrombocytopenic purpura developed during the conservative treatment of anti-phospholipase A2 receptor antibody-positive idiopathic membranous nephropathy: a case report.

BACKGROUND: Idiopathic membranous nephropathy (MN) is one of the major glomerulonephritis that cause nephrotic syndrome. The phospholipase A2 receptor (PLA2R) has recently been identified as an endogenous antigen of idiopathic MN. Thrombotic thrombocytopenic purpura (TTP) is a disorder characterized by schistocytes, hemolytic anemia, thrombocytopenia, and organ dysfunction which occurs as a result of thrombi. Patients with acquired TTP have autoantibodies against a disintegrin and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13). These autoantibodies act as an inhibitor and cause ADAMTS13 deficiency. Idiopathic MN and acquired TTP are usually considered as independent autoimmune diseases. We experienced a patient who developed TTP during the conservative treatment of idiopathic MN, with the coexistence of ADAMTS13 inhibitor and anti-PLA2R antibody. CASE PRESENTATION: A 73-year-old man presented with thrombocytopenia, hemolytic anemia, disturbance of consciousness, and acute kidney injury after 4-year course of biopsy-proven idiopathic MN. ADAMTS13 activity was undetectable and the ADAMTS13 inhibitor was identified. Additionally, he was positive for anti-PLA2R antibody. The patient did not have any diseases that could cause secondary thrombotic microangiopathy, and he was diagnosed with acquired TTP. Steroid therapy and plasma exchange were initiated and the acquired TTP resolved. MN achieved remission 3 months after the anti-PLA2R antibody disappeared. CONCLUSIONS: This is the first reported case of acquired TTP developed during conservative treatment of idiopathic MN, with both ADAMTS13 inhibitor and anti-PLA2R antibody positive at the onset of the TTP. The present case suggests that idiopathic MN might be associated with the development of some cases of acquired TTP.

Expression of Nectin-4 and PD-L1 in Upper Tract Urothelial Carcinoma.

Enfortumab vedotin is a novel antibody-drug conjugate targeting Nectin-4, which is highly expressed in urothelial carcinoma. However, the expression status of Nectin-4 in upper tract urothelial carcinoma (UTUC) remains unclear. The relationship between Nectin-4 and Programmed Death Ligand 1 (PD-L1) in UTUC is also ambiguous. We performed immunohistochemical analysis of 99 UTUC tissue microarray to assess the expression of Nectin-4 and PD-L1 in UTUC. Nectin-4-positivity was detected in 65 (65.7%) samples, and PD-L1 was detected in 24 (24.2%) samples. There was no correlation between the expression of Nectin-4 and PD-L1. Patients with strong Nectin-4-expressing tumors had a significantly higher risk of progression (p = 0.031) and cancer-specific mortality (p = 0.036). Strong Nectin-4 expression was also an independent predictor of disease progression in the high-risk group (pT3 ≤ or presence of lymphovascular invasion or lymph node metastasis) (Hazard ratio, 3.32 [95% confidence interval, 1.20-7.98; p = 0.027]). In conclusion, we demonstrated that Nectin-4 expression rate in UTUC was 65.7% and independent of PD-L1 expression. Strong Nectin-4 expression was associated with worse progression-free survival in high-risk UTUC. These findings suggested that enfortumab vedotin may be effective in a broad range of patients with UTUC, regardless of PD-L1 expression.

[A Case of Adenosquamous Carcinoma of Pancreas Treated with Conversion Surgery after Systemic Chemotherapy].

CASE: A man in his 60s reported upper abdominal pain; close examination revealed a tumor in the body-tail of the pancreas that was suspected to be infiltrating the stomach. Multiple liver lesions(S3, S4)were also detected. Histological examination by EUS-FNA showed poorly-differentiated carcinoma; thus, this case was diagnosed with unresectable pancreatic cancer with liver metastases(cT3, cN1[No. 7], cM1[P0, H1], cStage Ⅳ: JPS 7th). After 2 kinds of systemic chemotherapy(9 courses of GEM plus nab-PTX and 9 courses of modified FOLFIRINOX), obvious distant metastases or local progression did not appear and conversion surgery was scheduled. Although a metastatic lesion was identified at S5 of the liver just before the surgery, it was assumed that an R0 resection could be achieved; therefore, the operation(distal pancreatectomy with combined proximal gastrectomy, left adrenalectomy, lymph node dissection, partial hepatectomy of S5, and cholecystectomy)was performed. Histopathological examination showed squamous metaplasia of the epithelial tissue combined with glandular formation. This case was, thus, diagnosed as adenosquamous carcinoma of pancreas. This patient was discharged 90 days after the operation. The patient is still alive 2 years and 2 months since the first diagnosis.

[Two Cases of Intraductal Papillary Neoplasm of the Bile Duct(IPNB)Resected with Hepatectomy].

Case 1: A man in his 70s was referred to our hospital for further examination of a liver tumor(S3, 3 cm)detected by ultrasonography. Multimodal image examination showed a cystic lesion with solid papillary components located in the S4 accompanied by dilatation of the surrounding intrahepatic bile duct. Although biliary cytology did not indicate confirmed malignancy, the lesion was thought to be an intraductal papillary neoplasm of bile duct(IPNB)with malignant potential, and a left lobectomy was performed. Histopathological examination revealed a papillary tumor in the intrahepatic bile duct which consisted of atypical epithelial cells of pancreatobiliary type, and the lesion was diagnosed as an IPNB with high-grade intraepithelial neoplasia. Case 2: A woman in her 70s was referred to our hospital because of a liver tumor(S4, 8 cm)detected by ultrasonography. Multimodal image examination showed a cystic lesion localized to the liver(S3, 8 cm), and endoscopic retrograde cholangiopancreatography(ERCP)showed continuity of the cyst and the intrahepatic bile duct. The biliary cytology was positive, and the lesion was thought to be a malignant IPNB. After preoperative drainage of the cystic lesion, a left lobectomy was conducted. Histopathological examination showed that the papillary tumor localized to the bile duct and atypical epithelium cells of pancreatobiliary type were infiltrating into the surrounding matrix. We diagnosed this tumor as an IPNB with an associated invasive carcinoma.

Uridine 5'diphospho-glucuronosyltransferase 1A expression as an independent prognosticator in urothelial carcinoma of the upper urinary tract.

OBJECTIVE: To determine the expression status of uridine 5'diphospho-glucuronosyltransferase 1A, a major phase II drug metabolism enzyme, in upper urinary tract urothelial carcinoma, as well as to assess its prognostic significance. METHODS: We immunohistochemically stained for uridine 5'diphospho-glucuronosyltransferase 1A in tissue microarray consisting of 99 upper urinary tract urothelial carcinoma samples and paired non-neoplastic urothelial tissues. We also assessed the effect of uridine 5'diphospho-glucuronosyltransferase 1A knockdown on urothelial cancer cell growth. RESULTS: Uridine 5'diphospho-glucuronosyltransferase 1A was positive in 92.9% (27.3% weak [1+], 37.4% moderate [2+], 28.3% strong [3+]) of tumors, which was significantly (P < 0.001) lower than in benign urothelial tissues (98.8%; 3.5% 1+, 18.8% 2+, 76.4% 3+). All 37 (100%) non-muscle-invasive versus 55 (88.7%) of 62 muscle-invasive tumors (P = 0.043) were immunoreactive for uridine 5'diphospho-glucuronosyltransferase 1A. The rates of moderate-to-strong uridine 5'diphospho-glucuronosyltransferase 1A expression and its positivity were also strongly associated with the absence of concomitant carcinoma in situ (P = 0.034) and lymphovascular invasion (P = 0.016), respectively. However, there were no statistically significant associations between uridine 5'diphospho-glucuronosyltransferase 1A expression and tumor grade or pN/M status. Uridine 5'diphospho-glucuronosyltransferase 1A loss in M0 tumors was strongly associated with lower progression-free survival (P < 0.001) and cancer-specific survival (P < 0.001) rates. Multivariate analysis further identified a strong correlation of uridine 5'diphospho-glucuronosyltransferase 1A positivity with reduced cancer-specific mortality (hazard ratio 0.28, P = 0.018). Meanwhile, uridine 5'diphospho-glucuronosyltransferase 1A knockdown in urothelial cancer cells resulted in significant increases in their viability and migration. CONCLUSIONS: These results suggest a preventive role of uridine 5'diphospho-glucuronosyltransferase 1A signals in the development and progression of upper urinary tract urothelial carcinoma. Loss of uridine 5'diphospho-glucuronosyltransferase 1A expression might serve as an independent predictor of poor prognosis in patients with upper urinary tract urothelial carcinoma.

Expression of Phospho-ELK1 and Its Prognostic Significance in Urothelial Carcinoma of the Upper Urinary Tract.

Using preclinical models, we have recently found that ELK1, a transcriptional factor that activates downstream targets, including c-fos proto-oncogene, induces bladder cancer outgrowth. Here, we immunohistochemically determined the expression status of phospho-ELK1, an activated form of ELK1, in upper urinary tract urothelial carcinoma (UUTUC). Overall, phospho-ELK1 was positive in 47 (47.5%; 37 weak (1+) and 10 moderate (2+)) of 99 UUTUCs, which was significantly (P = 0.002) higher than in benign urothelium (21 (25.3%) of 83; 17 1+ and 4 2+) and was also associated with androgen receptor expression (P = 0.001). Thirteen (35.1%) of 37 non-muscle-invasive versus 34 (54.8%) of 62 muscle-invasive UUTUCs (P = 0.065) were immunoreactive for phospho-ELK1. Lymphovascular invasion was significantly (P = 0.014) more often seen in phospho-ELK1(2+) tumors (80.0%) than in phospho-ELK1(0/1+) tumors (36.0%). There were no statistically significant associations between phospho-ELK1 expression and tumor grade, presence of concurrent carcinoma in situ or hydronephrosis, or pN status. Kaplan-Meier and log-rank tests revealed that patients with phospho-ELK1(2+) tumor had marginally and significantly higher risks of disease progression (P = 0.055) and cancer-specific mortality (P = 0.008), respectively, compared to those with phospho-ELK1(0/1+) tumor. The current results thus support our previous observations in bladder cancer and further suggest that phospho-ELK1 overexpression serves as a predictor of poor prognosis in patients with UUTUC.

[Two Cases of Clear Cell Adenocarcinoma Arising in Urethral Diverticulum].

We report two cases of clear cell adenocarcinoma arising in the urethral diverticulum. Case 1 occurred in a 79-year-old woman presenting with complaints of frequent micturition. Magnetic resonance imaging (MRI) revealed a localized urethral diverticular tumor. Transurethral resection of the tumor was performed, and the final histopathological diagnosis was clear cell adenocarcinoma. Anterior pelvic exenteration was performed. She had no recurrence 15 months after surgery. Case 2 occurred in a 79-year-old woman presenting with urinary incontinence. As in Case 1, MRI and histopathological findings of transurethral resection of the tumor revealed clear cell adenocarcinoma in the urethral diverticulum. Anterior pelvic exenteration and ileal conduit formation were performed. She had no recurrence 16 months after surgery. Clear cell adenocarcinoma in the urethral diverticulum is very rare. We review 17 cases of clear cell adenocarcinoma arising in the urethral diverticulum in Japan.

[The Vaginal Metastasis of Ureteral Carcinoma after Left Nephroureterectomy: A Case Report].

69-year-old woman underwent left nephroureterectomy for left ureteral cancer (urothelial carcinoma (UC), high grade, pT3pN0) in September 2013. She returned to our hospital presenting with asymptomatic macrohematuria in July 2014. Cystoscopy showed tiny papillary tumors in the bladder. We also found genital bleeding from multiple papillary tumors on the vaginal wall. We performed transurethral resection of the bladder tumor and a biopsy of the vaginal wall demonstrated non-invasive UC, high grade. Pelvic magnetic resonance imaging after the operation showed no infiltration outside the bladder wall and vaginal wall. Therefore, we performed endoscopic excision of the vaginal tumor. However we could not resect all vaginal tumors. Irradiation of the vagina and uterus was performed under the diagnosis of metastasis of UC tovagina. Vaginal UC is extremely rare and this is the 26th case report in the literature.

Histochemical and immunoelectron microscopic analysis of ganglioside GM3 in human kidney.

BACKGROUND: Gangliosides are amphipathic lipids ubiquitously expressed in all vertebrate cells. They have been reported to play pivotal roles in cell morphology, cell adhesion, signal transduction, and modulation of immune reaction. Although human kidney contains various kinds of ganglioside, their physiological and pathophysiological roles have not been elucidated yet. As ganglioside GM3 is the most abundant ganglioside in human kidney, we tried to reveal the distribution of GM3 using histological analysis. METHODS: Macroscopically normal parts of operatively resected kidney from renal cell carcinoma patients were used for analyses. Immunohistochemical and immunoelectron microscopic analyses were performed with anti-GM3 antibody. RESULTS: Immunohistochemical analyses showed that GM3 was observed in glomeruli and renal proximal tubules. Immunoelectron microscopy demonstrated that GM3 was localized on the foot process of podocyte and also in Golgi region of renal proximal tubule cells. CONCLUSIONS: Ganglioside GM3 might take a part of the negative electric charge on the surface of podocyte and its multiple physiological actions may play pivotal roles for maintaining glomerular function.

Our experience of treating undifferentiated gastric carcinoma: report of four cases.

Undifferentiated gastric carcinoma is a rare histopathological type of cancer that does not show any differentiation toward adenocarcinoma or squamous cell carcinoma. It is thought to be highly malignant, and is associated with a poor prognosis. However, its clinical behavior has not yet been fully analyzed because of its rarity. We herein review the clinical characteristics and prognoses of patients with undifferentiated gastric carcinoma treated at our institutions. Among 2,651 gastric cancer patients, four (0.2 %) were histopathologically diagnosed to have undifferentiated carcinoma. These four patients included three males and one female. The median age of the patients was 60-year old (range 47-75). Three cases had distant metastases at diagnosis. One of these three cases was treated with chemotherapy alone, and the other two were treated with palliative gastrectomy and chemotherapy. The patient with no distant metastasis underwent curative gastrectomy and adjuvant chemotherapy. All patients died of cancer at a median of 5.4 (range 3.5-7.1) months after their diagnoses.

Endoglin expression in upper urinary tract urothelial carcinoma is associated with intravesical recurrence after radical nephroureterectomy.

OBJECTIVES: To evaluate the expression and prognostic significance of endoglin in patients with upper urinary tract urothelial carcinoma. METHODS: zArchival formalin-fixed and paraffin-embedded tissues from 99 cases of primary upper urinary tract urothelial carcinomas treated with nephroureterectomy were retrieved. Tissue microarrays were constructed with triplicate tumor samples and paired non-neoplastic urothelium. Tissue microarrays were analyzed using immunohistochemistry for endoglin, and the associations between clinicopathological parameters and outcome were studied. RESULTS: Endoglin expression was significantly higher in the endothelium of upper urinary tract urothelial carcinomas than in paired benign urothelium (P < 0.001). Endoglin expression was not associated with pathological T stage or tumor grade, and it was not associated with increased hazard ratios for cancer-specific mortality, tumor recurrence in the lymph node or distant metastasis. However, expression of endoglin was significantly associated with intravesical recurrence, when adjusting for other relevant clinicopathological variables (P = 0.015). CONCLUSIONS: Endoglin is overexpressed in the endothelium of upper urinary tract urothelial carcinomas when compared with normal urothelium, and this overexpression seems to be associated with a higher risk of intravesical recurrence. Therefore, endoglin could be a biomarker for the prediction of intravesical recurrence, as well as a potential therapeutic target.

[A Case of Perirenal Inflammatory Liposarcoma].

A 65-year-old man had been hospitalized for examination of melena at a separate facility. Computed tomography (CT) showed left renal mass and he was referred to our hospital. Magnetic resonance imaging (MRI) revealed a tumor without adipose components in the perirenal space. Preoperative diagnosis was retroperitoneal malignant tumor. Tumor excision and left nephrectomy were performed. Pathologic evaluation revealed inflammatory liposarcoma. He has been followed up for 10 months with no additional treatment and no evidence of local recurrence was seen.