[A Case of Hilar Cholangiocarcinoma Arising during Long-Term Follow-Up of Hepatolithiasis].

A 91-year-old man had a history of cholecystectomy and choledochostomy for cholecystolithiasis and choledocholithiasis. Eleven years earlier, intrahepatic stones were found in the posterior bile duct, and he did not wish to undergo treatment. Over time, worsening of the intrahepatic stones and dilation of the intrahepatic bile duct were observed. At 91 years old, enhanced abdominal CT revealed wall thickening of the hilar bile duct, and MRCP showed stenosis of the hilar bile duct. Endoscopic retrograde cholangiography showed no contrast in the right intrahepatic bile duct and marked dilation of the left intrahepatic bile duct. Brush cytology confirmed adenocarcinoma, leading to a diagnosis of hilar cholangiocarcinoma. He underwent open right and caudal lobectomy with biliary reconstruction. Histopathological examination revealed a hilar cholangiocarcinoma, T3N1M0, Stage Ⅲc, mainly located at the confluence of the right and left hepatic ducts. This case suggests a potential association between hepatolithiasis and hilar cholangiocarcinoma, emphasizing the importance of regular imaging examinations for timely surgical resection. Early intervention, including liver resection, is recommended for the management of hepatolithiasis.

[Long-Term Complete Response by CapeOX plus Nivolumab Chemotherapy for Postoperative Recurrence of Gastric Cancer-A Case Report].

A 73-year-old man underwent upper gastrointestinal endoscopy during a medical check-up that revealed a Type 2 lesion in the anterior wall of the gastric body. The biopsy confirmed tub2. A contrast-enhanced CT scan revealed focal wall thickening and lymphadenopathy in the gastric body. The patient was diagnosed with gastric cancer(M, ante, Type 2, T4aN1M0, Stage ⅢA). Laparotomy total gastrectomy D2 dissection and Roux-en-Y reconstruction were performed. Pathological results were tub1, int, INF b, ly0, v1, pT4aN0M0, pStage ⅡB. S-1(100 mg/day)was started as adjuvant chemotherapy but discontinued after 3 courses due to anorexia(Grade 2). Multiple pulmonary metastases(both lungs, 5)were confirmed by CT examination 9 months after the operation. A diagnosis of gastric cancer recurrence was made, and CapeOX plus nivolumab was started as first-line therapy. After 2 courses, lung metastases tended to shrink. The lesion developed a complete response(CR)after 3 months. After that, CapeOX plus nivolumab was continued, but peripheral neuropathy(Grade 2)was observed in the 15th course. With continued capecitabine monotherapy and nivolumab(impaired liver function [Grade 3]for irAE), despite the maintenance of CR, hepatic function increased repeatedly(Grade 3)and led to the discontinuation of chemotherapy upon patient's request. Currently, CR has been maintained for 5 years and 6 months after recurrence.

[A Case of Repeat Pancreatectomy-Robotic Spleen-Preserving Distal Pancreatectomy after Robotic Pancreaticoduodenectomy].

Laparoscopic pancreaticoduodenectomy has been covered by insurance since 2016 in Japan, and advance laparoscopic and robotic pancreaticoduodenectomy has been also covered by insurance since 2020 in Japan. It has been reported that laparoscopic pancreatectomy causes few postoperative adhesions in the abdominal cavity and that repeat laparoscopic surgery could be performed. However, in robotic pancreatectomy, there have been no such reports yet. We reported that even after robotic pancreaticoduodenectomy, there were few adhesions in the abdominal cavity, and we were able to perform the robotic distal pancreatectomy with preservation of the splenic artery and vein. This suggested that robotic surgery was an effective treatment method for repeat pancreatectomy, given its low invasiveness and minimal adhesion.

[A Case of Conversion Surgery for Stage â £ ATP-Producing Gastric Cancer with Distant Metastasis].

We report a case in which a patient with advanced gastric cancer with liver metastasis and bulky N showed marked tumor shrinkage with chemotherapy, and underwent conversion surgery. A 77-year-old male. Patient was referred to our department because of advanced gastric cancer. Upper gastrointestinal endoscopy revealed type 2 advanced cancer in the posterior wall of the gastric antrum. Abdominal CT showed thickening of the gastric wall in the same region and bulky lymph node enlargement and para-aortic lymphadenopathy behind the stomach. Staging laparoscopy showed the primary tumor and bulky lymph nodes forming a single mass, invading the pancreas, jejunum, and mesentery, and a solitary mass in the hepatic S3. Biopsy pathology revealed adenocarcinoma. We diagnosed the advanced gastric cancer cT4b(pancreas, jejunum), N2M1 (LYM, HEP), P0CY0, Stage ⅣB. After 2 courses of systemic chemotherapy FOLFOX/nivolumab, total gastrectomy, D2 node dissection, splenectomy pancreas tail resection, cholecystectomy, hepatic resection, partial transverse colon resection, partial jejunum resection, Roux-en-Y reconstruction. R0 resection was performed. The operative time was 620 minutes and blood loss was 1,025 mL. Pathologically, the patient was diagnosed with hepatoid adenocarcinoma, ypT4bN1M1(LYM, HEP), ypStage Ⅳ. The pathological efficacy evaluation was Grade 1a in the primary tumor. The patient has been recurrence-free for 9 months since the initial diagnosis.

Minimally invasive liver resection for cholangiolocellular carcinoma: A single-institution experience.

INTRODUCTION: Cholangiolocellular carcinoma (CoCC) resembles cholangiocellular carcinoma (CCC) and presents a variety of imaging findings; thus, preoperative diagnosis is often difficult. METHODS: We retrospectively studied patients who were diagnosed with CoCC at the Kansai Rosai Hospital from 2006 to 2021 and treated by laparoscopic liver resection (LLR) or open liver resection (OLR). RESULT: Among 918 liver resections, 15 patients were diagnosed with CoCC: 11 underwent LLR and 4 OLR. For LLR and OLR, respectively, patient age was 69.9 ± 6.8 and 72.8 ± 10.6, sex was M/F: 10/1 and 2/2, Child-Pugh was A/B/C: 10/1/0 and 4/0/0, liver damage was A/B/C: 8/3/0 and 4/0/0, preoperative diagnosis was CoCC/CCC/HCC: 1/2/8 and 2/2/0, pathological stage of Union for International Cancer Control (UICC) was IA/IB/II/IIIA/IIIB/IV: 8/0/2/1/0/0 and 0/0/3/0/1/0 (p = .0312), and extent of liver resection was Hr0/HrS/Hr1/Hr2/: 3/0/5/3 and 1/1/0/2. In LLR and OLR, respectively, operation time was 417.5 ± 191.0 and 407.5 ± 187.9 min, blood loss was 123.3 ± 217.4 and 1385.0 ± 1038.7 mL, and postoperative hospital stay was 12.2 ± 13.7 and 15.0 ± 6.6 days. For stages I and II/III, respectively, the 5-year disease-free survival rates were 100.0% and 34.3%, and the 5-year overall survival rates were 100.0% and 55.6%. For stage II/III LLR and OLR, respectively, the 3-year disease-free survival rates were 33.3% and 37.5% (p = .8418), and the 5-year overall survival rates were 66.7% and 50.0% (p = .8084). CONCLUSION: Although further studies are still needed to confirm, minimally invasive liver resection without lymph node dissection is one of a safe and effective approach to the management of CoCC.

Usefulness of blood flow evaluation by indocyanine green fluorescence in laparoscopic or robot-assisted surgery for colorectal cancer with persistent descending mesocolon.

A persistent descending mesocolon is defined as a congenital fixation anomaly caused by the defective membrane fusion of the descending colon and the lateral abdominal wall. Anatomically, in persistent descending mesocolon, the left colonic artery is often shortened, and joins the marginal artery soon after its bifurcation from the inferior mesenteric artery, while the colonic mesentery often adheres firmly to the mesentery of the small intestine. As a result of these characteristics, anatomical knowledge of the persistent descending mesocolon and preservation of bowel blood flow are important during surgery for left-sided colorectal cancer to avoid adverse events. Moreover, indocyanine green based blood flow assessment is useful for the detailed evaluation of bowel ischemia at the anastomotic site. Here we report the usefulness of blood flow evaluation using indocyanine green fluorescence in laparoscopic or robot-assisted surgery for three patients with colorectal cancer and persistent descending mesocolons.

[A Case of Inguinal Hernial Sac Metastasis of Cecal Cancer Resected with TAPP Approach].

Malignant tumor occurring in the inguinal region are relatively infrequent, and metastatic tumor is extremely rare. We report a case of inguinal hernial sac metastasis of cecal cancer resected with TAPP approach. The case is a 80's man. One year and 6 months after cecal cancer surgery, contrast-enhanced computer tomography(CT)examination revealed a solitary tumor in the right inguinal canal. We diagnosed inguinal hernia sac metastasis of cecal cancer and performed surgery. The mass in the hernia sac was resected with the TAPP approach. Histopathological findings were consistent with peritoneal metastasis directly to the inguinal hernia sac. The patient has been alive without 2 years after metastasectomy. It is necessary to treat patients with a history of malignant disease with keeping the possibility of inguinal hernia sac metastasis in mind.

[A Case of Multiple Postoperative Recurrence of Hepatocellular Carcinoma Successfully Treated with Atezolizumab plus Bevacizumab].

We report a case of postoperative multiple recurrence of hepatocellular carcinoma(HCC)treated with atezolizumab plus bevacizumab. A 73-year-old man with a chief complaint of abdominal distention was indicated a 90-mm-sized tumor extending from the lateral hepatic segment to the extrahepatic region by a contrast-enhanced CT scan of the abdomen. He underwent a laparoscopic liver resection of the lateral segment for suspected HCC, and was diagnosed as pStage Ⅱ HCC. Six months after surgery, multiple recurrent at intrahepatic lesions and suspected lymph node recurrence or peritoneal dissemination were observed, and tumor markers were markedly elevated. The patient was diagnosed with multiple intrahepatic and extrahepatic recurrences of postoperative HCC and started combination chemotherapy with atezolizumab (1,200 mg/body)plus bevacizumab(15 mg/kg). After the initiation of the therapy, tumor size reduction and normalization of tumor markers were observed, and at 17 months postoperatively, tumor size reduction has been maintained and tumor markers were in the normal range. We report a case of postoperative intrahepatic and extrahepatic multiple recurrences of he patocellular carcinoma treated with atezolizumab plus bevacizumab.

[The Investigation about Cases Performed Laparoscopic Pancreas-Sparing Duodenectomy in Our Hospital].

INTRODUCTION: There are few reports of surgery which preserve the function of pancreas for benign or low malignant tumors. While we have introduced laparoscopic pancreaticoduodenectomy (LPD), we have also performed laparoscopic pancreas-sparing duodenectomy (LPSD). In the present study, we investigated surgical techniques and results of LPSD. MATERIALS AND METHODS: Between October 2019 and January 2022, 3 patients were underwent LPSD. The procedure was performed after obtaining approval from the Ethics Review Committee of our hospital. RESULTS: Three patients conducted LPSD were all males with a median age of 74 years, and diagnoses were adenomas of duodenum in 2 cases and gastrointestinal stromal tumor of duodenum in 1 case. The median blood loss was small amount. The median operative time was 430 minutes, and the median postoperative hospital stay was 13 days. One of the cases was performed with conversion to HALS. In LPSD, an intraoperative ultrasonography and an intraoperative radiographic contrast study were performed to confirm that the ampulla of Vater was preserved. There were no postoperative complications. CONCLUSION: We experienced cases performed LPSD in our hospital. We need further research for feasibility and safety of the procedure.

[GEM plus CDDP Combination Therapy for Unresectable Biliary Tract Cancer-A Single Institution Experience].

BACKGROUND: Since a randomized phase Ⅲ trial conducted in the UK in 2009 showed the superiority of gemcitabine (GEM)plus cisplatin(CDDP)combination therapy over GEM monotherapy, GEM plus CDDP combination therapy has been first-line chemotherapy for unresectable biliary tract cancer. METHODS: GEM plus CDDP combination therapy was administered to 29 patients with unresectable biliary tract cancer from 2016 to 2021. RESULTS: The mean age was 71.9 years, male/ female 19/10. The target of chemotherapy was below, local progression was 3 cases, first distant metastasis 7 cases, metastatic recurrence 19 cases. The type of cancer was below, intrahepatic bile duct carcinoma was 8 cases, hepatic hilar bile duct carcinoma 6 cases, gallbladder carcinoma 5 cases, cystic duct carcinoma 1 case, distal bile duct carcinoma 6 cases, and papilla Vater's cancer 3 cases. The dosing period was 23.1 weeks(range 2-52 weeks). The relative dose intensities of GEM and CDDP were 73.7% and 75.1%. The adverse events were below, the hematological toxicities of Grade 3 or higher were neutropenia(65.5%), leukopenia(3.4%), and thrombocytopenia(10.3%). Non-hematological toxicities of Grade 2 or higher were fatigue(13.7%)and skin rash(6.9%). There was no interstitial pneumonia. The disease control rate was 66.7 %(complete response, n=0; partial response, n=6; stable disease, n=10; progressive disease, n=8). CONCLUSION: GEM plus CDDP combination therapy was safe to perform and was an effective treatment for unresectable biliary tract cancer.

Fluorescence cholangiography for detection of a cystic duct drained into an accessory hepatic duct: A case report.

INTRODUCTION: Laparoscopic cholecystectomy is a safe and standard procedure, but serious bile duct injury may occur due to anatomical anomalies of the biliary tract, especially the accessory hepatic duct. The use of intraoperative fluorescence cholangiography with indocyanine green during laparoscopic cholecystectomy can reportedly prevent bile duct injury. PRESENTATION OF CASE: A 55-year-old woman with upper abdominal pain was referred to our hospital. Laboratory investigations revealed elevated leukocytes and biliary enzymes, while computed tomography demonstrated increased fatty tissue density around the gallbladder. Magnetic resonance cholangiopancreatography and drip infusion cholangiographic-computed tomography showed that the cystic duct drained into an accessory hepatic duct. Due to the diagnosis of cholelithiasis with a biliary anomaly, we performed laparoscopic cholecystectomy using fluorescence cholangiography with indocyanine green. We were able to recognize the accessory hepatic duct and cystic duct, then safely dissect the cystic duct without bile duct injury. DISCUSSION: Laparoscopic cholecystectomy is generally regarded as a safe procedure, but complications and even mortalities can arise in patients with anatomical anomalies of the biliary tract. The aid of intraoperative fluorescence cholangiography with indocyanine green allowed to recognize and identify the accessory hepatic duct and cystic duct, allowing us to operate without injury to the bile duct. CONCLUSIONS: Our experience supports the ease of use, safety, and effectivity of fluorescence cholangiography with indocyanine green. This may become the optimal standard technique to prevent bile duct injury.

[Robotic and Laparoscopic Pancreaticoduodenectomy for the Elderly Patients-A Single Institutional Experience].

INTRODUCTION: Laparoscopic pancreaticoduodenectomy(LPD)has been covered by insurance since 2016 in Japan. Advance LPD and robotic pancreaticoduodenectomy(RPD)has been also covered by insurance since 2020 in Japan. The aim of this study was to analyze the perioperative results and outcomes of RPD and LPD for the elderly patients and to compare to the non-elderly patients. PATIENTS AND METHOD: Between July 2020 and April 2023, 67 patients underwent RPD and between May 2012 and February 2021, 63 patients underwent LPD at Kansai Rosai Hospital. Sixty-seven RPD and 62 LPD patients without extended resection were divided into 2 groups those who were over 75 years old(R/LPD E)(n=55)and under 74 years old(R/LPD non-E)(n=74). Control patients who received open pancreaticoduodenectomy(OPD)without extended resection between April 2010 and April 2023 were also divided into 2 groups those who were over 75 years old(OPD E)(n =60)and under 74 years old(OPD non-E)(n=78). The patient age was 79.0 and 60.5 years, the male to female ratio was 35/20 and 45/29, disease ratio(invasive ductal carcinoma or not)was 7/48 and 9/65 in R/LPD E and R/LPD non-E groups, respectively. The patient age was 79.0 and 79.5 years, the male to female ratio was 35/20 and 31/29, disease ratio (invasive ductal carcinoma or not)was 7/48 and 30/30(p<0.0001)in R/LPD E and OPD E groups, respectively. This study was approved by the Human Ethics Review Committee of Kansai Rosai Hospital(Certificate Number: 2001019). RESULTS: The average operation time was 644.6 and 675.2 minutes, an estimated blood loss was 220.8 and 134.4 g, postoperative pancreatic fistula(ISGPS 2016, [-]/BL/Grade B/C)was 24/18/13/0 and 28/25/21/0, delayed gastric emptying(ISGPS 2007, [-]/Grade A/B/C)was 48/0/4/3 and 61/2/6/5 and postoperative hospital stay was 27.9 and 25.9 and in R/LPD E and R/LPD non-E groups, respectively. No significant differences were noted between the groups, However, postoperative complication over Ⅲa Clavien-Dindo classification was 8(15.7%)and 3(4.4%)cases(p=0.0319)in R/LPD E and R/ LPD non-E groups. The average operation time was 644.6 and 492.1 minutes(p<0.0001), an estimated blood loss was 220.8 and 534.8 g(p=0.0004), postoperative pancreatic fistula(ISGPS 2016, [-]/BL/Grade B/C)was 24/18/13/0 and 27/8/24/1(p=0.0442), postoperative hospital stay was 27.9 and 42.0(p=0.0490)in R/LPD E and OPD E groups, respectively. CONCLUSION: The R/LPD was undergone in safety, even for the over 75 years old patients.

[Robot Assisted Para-Aortic Lymphadenectomy in Gastric Cancer Surgery].

Para-aortic lymphadenectomy in gastric cancer surgery is a highly difficult surgical technique. In our hospital, we introduced robotic surgery in anticipation of the minimal invasiveness and advanced operability. We use a tunneling approach that progresses from the Treitz ligament to the peri-aorta. The transverse mesocolon is expanded with a tissue grasping clip, and the retroperitoneum is incised from the side of the Treitz ligament to approach the abdominal aorta and inferior vena cava. The No.16b1 and No.16a2 latero lymph nodes can be dissected with a good visual field. When it is judged that the visual field development of the No.16a2 inter-lymph nodes is poor, Kocher's operation is added. Since 2016, 18 patients have undergone para-aortic lymphadenectomy, 3 of whom underwent robotic surgery in our hospital. R0 resection was performed in all the cases, and 22.5 lymph nodes were dissected as No.16 lymph nodes(20.0 in all the cases included laparotomy). Although only a small number of patients were examined, robot-assisted para-aortic lymphadenectomy was considered safe.

[A Case of Combined Use of Mohs Paste and Radiation Therapy for Advanced Breast Cancer with Bleeding].

A 75-year-old female, at her initial presentation, the tumor occupied her entire right breast, with a foul-smelling exudate. A biopsy revealed ER-positive, HER2-negative breast cancer, and CT revealed multiple lung metastases. Paclitaxel and fulvestrant were administered sequentially, the bleeding from the right breast mass stopped and the mass flattened. But, as the tumor progressed, the right breast mass re-enlarged and began to re-bleed. Therefore, hemostatic treatment with Mohs paste was performed in parallel with tamoxifen. Hemostatic effect was observed for a while, but she gradually became refractory to Mohs paste, necessitating frequent blood transfusions. It was decided to discontinue systemic drug therapy and consider palliative treatment, and to perform radiation therapy in parallel with Mohs paste treatment for the purpose of local control. After radiation therapy, the bleeding has completely stopped and blood transfusion has not to be required for 6 months. Although systemic drug therapy has been discontinued at the patient's request, she is still alive. While systemic drug therapy was discontinued, we were able to confirm the pure local control effect of combination of radiation therapy and Mohs paste.

[A Case of Small Intestinal GIST Associated with Neurofibromatosis Type 1].

A 41-year-old male, with a history of neurofibromatosis type 1(NF1)was referred for further evaluation of positive fecal occult blood test. Abdominal contrast-enhanced CT incidentally showed a mass lesion with early darkening in the small intestine. It was suspected to be a small intestinal arteriovenous malformation, and surgery was performed. The tumor in the small intestine was resected under laparoscopic assistance. The histopathological diagnosis was gastrointestinal stromal tumors associated with NF1, which are usually located in the small intestine and relatively favorable prognosis.

[A Case of TMB-High Recurrent Peritoneal Seeding in Hilar Cholangiocarcinoma Treated with Pembrolizumab Therapy].

Tumor mutation burden(TMB)-High is known to potentially elicit a favorable response to immune checkpoint inhibitors. In this report, we present a case of recurrent hilar cholangiocarcinoma with TMB-High, in which we performed comprehensive treatment including immune checkpoint inhibitor pembrolizumab. The patient was a 58-year-old male diagnosed with hilar cholangiocarcinoma who underwent extended right hepatectomy, caudate lobe resection, bile duct excision, and bile duct reconstruction. Postoperatively, peritoneal seeding recurrence and liver metastasis were observed, indicating TMB-High. Therefore, pembrolizumab therapy was administered. The tumor marker CA19-9 significantly decreased, and the peritoneal seeding and liver metastatic lesions disappeared on imaging. In this case, we experienced the use of pembrolizumab monotherapy for TMB-High recurrent bile duct cancer with early postoperative peritoneal seeding recurrence. Further accumulation of cases is needed, but pembrolizumab monotherapy holds promise as a treatment option for TMB-High bile duct cancer at the hepatic hilum.

[Clinicopathological Characteristics of Early-Onset Colorectal Cancer(EOCRC)Cases in Our Hospital].

BACKGROUND: In recent years, the number of colorectal cancer in Europe and the U. S. has been decreasing, but there are increasing reports on the trend of early-onset colorectal cancer(EOCRC), which is a rare population with no established knowledge on its characteristics. SUBJECTS AND METHODS: Of 3,501 colorectal cancer cases treated at our hospital between April 2011 and December 2021, those aged 39 years and younger were included. RESULTS: There were 32 EOCRC cases, 11 males/21 females. The histological type was tub in 31 cases and por in 1 case. Postoperative adjuvant chemotherapy was administered in 14 patients, and 12 completed the scheduled course. Twenty nine patients underwent R0 resection, of which 6 patients had recurrence and 5 patients died of primary disease. In summary, although EOCRC patients were in good general condition and had a high completion rate of adjuvant chemotherapy, the relapse rate was high, suggesting the need for aggressive adjuvant chemotherapy and careful postoperative surveillance.

Impact of pathological complete response following neoadjuvant chemotherapy (gemcitabine, nab-paclitaxel, S-1) and radiation for borderline resectable pancreatic cancer: a case report and review of literature.

BACKGROUND: Pancreatic cancer (PC) is a highly lethal malignancy, even if surgical resection is possible (median survival: < 30 months). The prognosis of borderline resectable pancreatic cancer (BR-PC) is even worse. There is no clear consensus on the optimal treatment strategy, including pre/postoperative therapy, for BR-PC. We report a patient with BR-PC who achieved clinical partial response with neoadjuvant chemoradiation therapy (NACRT) and underwent curative resection, resulting in pathological complete response (pCR). CASE PRESENTATION: A 71-year-old man with jaundice and liver dysfunction was referred to our department because of a 48-mm hypo-vascular mass in the pancreatic head with obstruction of the pancreatic and bile ducts and infiltration of superior mesenteric vein and portal vein. The lesion was identified as atypical cells which suggested adenocarcinoma by biopsy, and he was administered NACRT: gemcitabine and nab-paclitaxel, following S-1 and intensity modulated radiation therapy. After reduction in the tumor size (clinical partial response), pancreaticoduodenectomy was performed, and pCR achieved. Postoperative adjuvant chemotherapy with S-1 was initially administered and the patient is currently alive with no recurrence as of 2 years after surgery. CONCLUSIONS: NACRT is a potentially useful treatment for BR-PC that may lead to pCR and help improve prognosis.

Solitary anterior mediastinal lymph node metastasis with pericardial invasion from colon cancer: A case report.

Colorectal cancer commonly metastasizes to the regional lymph nodes, liver, lungs and peritoneum. At present, mediastinal lymph node metastasis from colorectal cancer is uncommon and poorly understood. The present study reported a case of solitary anterior mediastinal lymph node metastasis with pericardial invasion from transverse colon cancer. An 82-year-old woman had a history of colectomy with regional lymph node dissection for transverse colon cancer (T1N1bM0 stage IIIA in the UICC classification). The patient had no symptoms, but follow-up contrast-enhanced computed tomography revealed an anterior mediastinal tumor compressing the heart 18 months after colectomy. The tumor showed fluorodeoxyglucose uptake on positron emission tomography. Resection of the anterior mediastinal tumor with pericardiectomy was performed. The tumor was 35x25 mm in size and was histopathologically characterized to be adenocarcinoma. These cells expressed cytokeratin (CK)20 and caudal-type homeobox protein 2 but not CK7 and thyroid transcription factor 1 on immunohistochemical analysis, confirming a diagnosis of metachronous mediastinal metastasis originating from colon cancer. The tumor cells invaded the adjacent pericardium and diaphragm pathologically. The patient has lived without recurrence 8 months after the surgery for mediastinal metastasis. In conclusion, clinicians should consider metastasis to the mediastinum during follow-up in patients with colorectal cancer. Surgery may be the most reliable treatment for solitary anterior mediastinal lymph node metastasis, preventing carcinomatous pericarditis through direct pericardial invasion.

Inguinal endometriosis with a disappearing mass preoperatively: A case report.

INTRODUCTION: Endometriosis is a common gynecological disease that affects approximately 10% of reproductive-age women. Inguinal endometriosis is uncommon, affecting only 0.6% of all patients with endometriosis. We present a case of inguinal endometriosis with a disappearing mass preoperatively. PRESENTATION OF CASE: A 44-year-old woman presented with a palpable mass and pain in her left inguinal region. Computed tomography showed a 20-mm mass near the pubic tubercle. After 2 months of observation, the mass became impalpable and could not be confirmed by computed tomography; however, the inguinal pain did not improve regardless of menstrual cycles. Resection of the inguinal mass and the entire extraperitoneal portion of the uterine round ligament was performed. Histopathological examination revealed endometrial glands and stroma with CD10-positive cells, which confirmed inguinal endometriosis diagnosis. Erythrophagocytic macrophages indicated endometriosis-related hematoma absorption. Her symptoms disappeared after surgery, and no postoperative complications occurred. DISCUSSION: For treating inguinal endometriosis, the complete removal of the mass and the entire extraperitoneal portion of the round ligament by an anterior approach is necessary to prevent postoperative residual symptoms and recurrence. However, the preoperative diagnosis of inguinal endometriosis remains a challenge and is frequently discovered incidentally by intraoperative findings and pathological examination. CONCLUSION: Clinicians should have a high suspicion of inguinal endometriosis and improved diagnostic precision to select the appropriate surgical approach. Regardless of menstrual variability, the feature of a decreased mass size caused by endometriosis-related hematoma absorption can serve as a preoperative diagnostic clue.