Retroperitoneal tumors (RPTs) are rare tumors that develop in soft tissues found in the retroperitoneal space. RPTs are treated in various departments such as gastroenterological surgery, urology, orthopedics, and obstetrics and gynecology. Compiling evidence for RPTs is not easy because this disease is not common and the clinical manifestation of RPTs is extremely complex and diverse. It is important, however, to collect and analyze the clinical data of RPTs using the national clinical database, to plan clinical trials for the treatment of RPTs, and to produce evidence for RPTs. It is also urgently necessary to establish a clinical guideline for RPTs. These efforts may finally systematize the treatment strategy for RPTs and may improve the overall prognosis of this rare disease.

Hepatic disorder is one of the commonly observed adverse effects during drug treatment. Clinically, fatty liver has been regarded as a benign reversible and non-harmful liver disease. Nonalcoholic fatty liver disease (NAFLD) is one of such diseases and in this study, the incidence of NAFLD due to tamoxifen (TAM) was retrospectively investigated. As a result, the incidence of NAFLD was as high as 29.1%. Of these cases, 68% was reversible ; however, the incidence of NAFLD due to TAM was high and improvement was not observed in some cases. Healthcare professionals should be aware of these findings.

Recently we have experienced a long complete response (for approximately 9 years) to the treatment with lapatinib plus capecitabine (LC regimen) for HER2-positive advanced breast cancer with brain metastases. In order to clarify the efficacy and safety of LC regimen, we made a retrospective analysis of 16 patients who received LC regimen for HER2-positive advanced and recurrent breast cancer with brain metastases between July 2009 and April 2019 at our institution. All patients underwent local therapy for brain metastases before LC regimen. Two patients were treated surgically while 14 received radiotherapy. A complete response was noted in two patients (12.5%), a partial response in eight patients (50.0%), and disease stable condition in one patient (6.2%), whereas there was disease progression in three patients (18.8%) and the remining two patients were not evaluated (12.5%). The response rate was 62.5% (10/16) ; the median time to progression was 8.9 months and the median overall survival was 13.6 months. Given these results and that oral use lapatinib and capecitabine are easy to administer, they should be considered for the treatment of HER2-positive advanced and recurrent breast cancer, especially with brain metastases.

Neuroendocrine tumors of the breast are rare and have been reported to account for 0.08 - 0.8% of all breast tumors. Among of them, the tumor appeared in the form of an intracystic tumor has been reported in only four cases in Japan. We herein report a case of noninvasive neuroendocrine tumor of the breast in the form of an intracystic tumor presented with intracystic hemorrhage.

An 81-year-old woman was referred to our hospital because of a right breast tumor. The tumor with smooth surface and clear margin located in the AC area of the right breast was about 5.0 cm in size, elastic-soft and quite movable. Mammography showed a round high-density mass with an almost regular margin. Ultrasonography showed a circumscribed intracystic tumor measuring 20×10 mm. The intracystic tumor was irregular in shape, and continued with the cyst wall. Enhanced CT scan demonstrated a high density lesion in the cystic lesion. Aspiration biopsy revealed malignant cytology. Simple mastectomy was performed with a diagnosis of intracystic tumor. The cut surface of the resected specimen demonstrated a 10 × 20 mm intracystic tumor in the 50 × 55 mm cyst. The pathological diagnosis was noninvasive neuroendocrine tumor, well-differentiated, positive for estrogen receptor and progesterone receptor and negative for HER2. Most of the tumor cells were positive by synaptophysin and chromogranin A staining. The patient received hormone therapy with an oral aromatase inhibitor. The patient is doing well without metastases as of 5 years after the operation.

The patient was a 72-year-old woman who had been admitted to our hospital with a left breast mass at the age of 69. She was diagnosed with left breast cancer (cT1cN0M0, cStage I) and underwent total mastectomy and sentinel lymph node biopsy. Lymph node metastasis was recognized and axillary dissection (Level II) was added. The pathology revealed invasive lobular carcinoma, 16×13 mm, ly(+), v(±), histological grade : 1, n2, hormone receptor positive, HER2 negative, and pStage IIIA. We recommended adjuvant chemotherapy, but she did not desire. She started oral administration of an aromatase inhibitor and radiation therapy. When DFI was 3 years and 1 month, an examination was carried out because the increase in CEA value, urination pain and hematuria were recognized. A contrast-enhanced CT scan revealed a mass extending from the bladder to the right ovary. We suspected ovarian invasion of bladder cancer. She underwent a bladder biopsy. The result was bladder metastasis of breast cancer. Endocrine therapy was continued, and radiotherapy was performed. Later, we introduced chemotherapy, but it was withdrawn with her request. She wished BSC. She developed dysuria 1 year and 3 months and died 1 year and 4 months after the diagnosis of bladder metastasis.

This paper deals with a patient who presented with paraneoplastic neurological syndromes (PNS) and was diagnosed with breast cancer by general examinations, whose PNS symptoms were improved after surgery for breast cancer. A 64-year-old woman presented with bilateral femoral pain, followed by progressive bilateral upper limb tremor, diplopia, eye movement disease, and myoclonus of the bilateral lower limbs. Anti-Ri antibody positive was clarified. Accordingly, paraneoplastic opsoclonus-myoclonus syndrome, a type of PNS, was diagnosed. General exploration disclosed that she had right breast cancer. We performed right Bt + SN. The postoperative diagnosis was made as pT1cN0M0 (invasive ductal carcinoma, ER 100%, PgR 100%, HER2 negative, and Ki-67.5%). The patient was given oral anastrozole after the operation. Within one month after the operation, her eye nystagmus, diplopia, limited eye movements were relieved. Thereafter, she developed muscular rigidity and was diagnosed with stiff-person syndrome. Intramedullary baclofen administration was sustained that led to an improving tendency of ADL. In treating a patient who manifests a variety of neurologic symptoms before and/or after diagnosis of breast cancer, PNS should be considered as a possible differential diagnosis.

Pancreatic metastases from breast cancer can arely cause a life-threatening condition. We report a case of a patient who went into hemorrhagic shock due to a metastatic lesion of the pancreas from breast cancer. A 55-year-old woman, with a history of right breast cancer 13 years earlier, had been treated with chemotherapy (weekly paclitaxel + bevacizumab) for a metastatic lesion of the pancreas body since it was pointed out 4 years earlier. She was emergently admitted to our hospital due to massive melena, when she manifested hypotension, and inflammatory reaction and mild anemia on a blood analysis. An enhanced abdominal CT scan showed a 60-mm sized metastatic lesion on the tail of pancreas with hematoma inside, and another lesion on the transvers colon. Penetration of the metastatic lesion to the transverse colon was suspected to cause melena. She underwent an emergency hemostasis by transcutaneous arterial embolization for persisting melena. Her hemodynamic status was stabilized temporally, but she went into hemorrhagic shock status again after massive melena. We successfully saved her life by performing an emergency distal pancreatectomy with splenectomy, transverse colectomy and colostomy. It is extremely rare that pancreatic metastasis from breast cancer can be life-threatening.

We have experienced three cases of descending necrotizing mediastinitis (DNM) treated with emergency drainage and intensive care. Case 1 : A 45-year-old man with untreated diabetes mellitus was diagnosed with DNM caused by untreated dental caries. He underwent mediastinal drainage through the cervical and thoracic approach (video-assisted thoracic surgery, VATS). He died of multiple organ failure 3 days after the surgery.

Case 2 : A 36-year-old woman with post-cardiac arrest syndrome was diagnosed with DNM when tracheostomy was performed. She underwent mediastinal drainage through the cervical approach. She was transferred to other institution from our hospital on postoperative day 96 with stenosis of the trachea.

Case 3 : A 48-year-old man was diagnosed with DNM caused by untreated dental caries. He underwent mediastinal drainage three times through the cervical and thoracic (VATS) and subxiphoidal approach. He was discharged on dependent gait from our hospital on postoperative day 106.

With a recent accumulation of clinical cases of DNM, the therapeutic strategies have been clarifying. More efficient transthoracic drainage method for life-threatening DNM cases and a multi professional collaboration for an early return to work are important.

An 81-year-old man underwent abdominal endovascular aortic repair and right internal iliac artery coiling for a right internal iliac artery aneurysm 2 years earlier. Postoperative CT showed no endoleak, but aneurysmal sac enlargement had continued. Open surgery was recommended, but the patient refused. He developed abdominal pain and urinary retention, and enhanced CT showed a giant internal iliac artery aneurysm that occupied the pelvic cavity and caused hydronephrosis. Right iliac artery aneurysm fenestration was therefore performed. During surgery, there was no endoleak, and endotension-induced aneurysm enlargement we diagnosed. The patient's postoperative course was uneventful.

The patient was a 59-year-old man who had been followed up after surgical treatment for a thoracic aortic aneurysm at the Department of Cardiovascular Surgery in our hospital. A contrast-enhanced CT scan conducted one year and 6 months after the surgery disclosed a tumorous lesion at the cardiac part of the stomach. Close exploration led to a diagnosis of a submucosal tumor 50 mm in diameter being present just under the gastric cardia. We decided to perform surgery. Considering the location and the diameter of the tumor, we selected laparoscopic proximal gastrectomy. He was discharged from our hospital on the 6^th postoperative day and his postoperative QOL was satisfactory. Histopathology revealed the tumor to be a submucosal tumor with the maximum diameter of 42 mm, consisting of large fusiform and polygonal cells, where an abundant of eosinophil granules was seen in the cytoplasm. Immunohistochemical staining for PAS, S-100 protein, or NSE was positive. Consequently, granular cell tumor of the stomach was diagnosed.

Granular cell tumor of the stomach is a rare entity and there have been only four cases, including ours, performed laparoscopic resection in Japan. We present our case with some bibliographical comments including selection of the treatments.

A 72-year-old man with a chief complaint of abdominal distention was referred to our department for close investigation and treatment. Abdominal contrast-enhanced computed tomography revealed a huge mass in the abdominal cavity continuing from the stomach, while positron emission tomography-computed tomography demonstrated the accumulation of fluorodeoxyglucose in the left cervical lymph node. Laparotomy showed a huge pedunculated tumor (170 × 110 × 85 mm) growing from the greater curvature of the gastric antrum, and a local gastrectomy was performed to remove it. Histopathological examination showed fascicular and confluent growth of cells with spindle-shaped nuclei. Immunohistochemical staining revealed c-kit and S-100 negativity and α-smooth muscle actin and desmin positivity. In addition, since the MIB-1 index was 55% and mitotic figures were high, the patient was diagnosed with leiomyosarcoma. A postoperative needle biopsy of the left cervical mass revealed the same histology as gastric leiomyosarcoma ; therefore, lymph node metastasis was identified. Gastric leiomyosarcoma is susceptible to hematogenous metastasis and lymphatic metastasis is very rare. This is the first reported case of gastric leiomyosarcoma with cervical lymph node metastasis in Japan.

A 74-year-old man was found to have a type 2 lesion in the greater curvature of the inferior gastric corpus on upper gastrointestinal endoscopy. The submucosa was elevated in the area around the lesion, and biopsy showed that it was tub1. Computed tomography (CT) showed enlargement of the gallbladder and thickening of its walls, as well as a continuous hypodense region from the hepatic umbilical region to the gastric antrum, and it was difficult to distinguish between gastric invasion of gallbladder cancer, peripheral invasion of gastric cancer, or the presence of both a cholecystitis-induced gastric wall abscess and gastric cancer. After antibiotic pretreatment, CT showed that the hypodense area in the stomach had contracted, and the submucosal elevation of the gastric cancer had also improved to 0-IIc. Cholecystitis-induced secondary gastric wall abscess and gastric cancer were diagnosed, and distal gastrectomy and cholecystectomy were performed. On pathological examination, T1bN0 gastric cancer was diagnosed, with the adjacent formation of an abscess from the serosa to the muscularis propria, and the gallbladder showed signs of acute cholecystitis with abscess formation and no signs of malignancy. Cholecystitis-induced secondary gastric wall abscess is a rare condition, and this case was made even more unusual by the adjacent presence of concomitant gastric cancer. Antibiotic pretreatment enabled the accurate preoperative diagnosis of gastric cancer.

A 67-year-old man had a fever on the 5th day after abdominal aortic aneurysm replacement. An aorto-duodenal fistula (ADF) was suspected. After gastrointestinal angiography, CT showed the ADF.

At surgery, omental plugging was performed using esophagogastroduodenoscopy.

ADF is a complication of abdominal aortic aneurysms and has a high fatality rate. There is no established treatment for ADF. Many cases require revascularization and gastrointestinal resection.

Taking into account the patient's general condition, omental plugging may be recommended as one of the surgical techniques for ADF.

An-83-year-old man was admitted to our hospital complaining of fatigue and painful urination. A mild elevation of the inflammatory response and urine turbidity were found. Contrast-enhanced CT and MRI showed wall thickening and an increased fat concentration in the terminal ileum and fistula between ileum and bladder. He was diagnosed with enterovesical fistula. We first carried out conservative therapy. However, since it proved to be unsuccessful, we thereafter performed reduced port surgery. A section of the small intestine around the fistula was removed and a fistula in the patient's bladder was closed with sutures under laparoscopic surgery. The patient's postoperative course was good. The pathological findings showed multiple ileal diverticula and inflammation around the perforated diverticula. Enterovesical fistula caused by ileal diverticulitis is a very rare occurrence. Laparoscopic surgery is therefore considered to be valuable as a less invasive treatment for enterovesical fistula with localized inflammation.

A 72-year-old woman was transported to our hospital with a consciousness disorder in the night. Blood tests showed an increased white blood cell count and C-reactive protein and metabolic acidosis. Abdominal CT showed sigmoid colon diverticulitis. Her septic shock did not improve with catecholamine therapy, so emergency laparotomy was performed the next morning. Intraoperative findings included necrosis of the large bowel from the sigmoid colon to the transverse colon. Colectomy of the large bowel from the sigmoid to the transverse colon and end-transverse colostomy were performed. The resected specimen showed diverticulitis of the sigmoid colon and the descending colon, and necrotizing obstructive colitis of the mouth side of each area of diverticulitis. Reports of obstructive colitis due to diverticulitis are rare but are expected to increase in the future with the increasing prevalence of diverticulosis. When examining patients with diverticulitis, it is important to keep in mind the complication of obstructive colitis, especially when stenosis is present.

A 73-year-old woman had been examined at another medical institution for abdominal pain. Cholecystitis and cholangitis were diagnosed, and her symptoms improved after endoscopic retrograde biliary drainage. Cholecystectomy was recommended, and since the patient expressed the wish to undergo the operation at our hospital, she was referred to our department. Abdominal plain computed tomography (CT) conducted during preoperative testing showed a nodule at the sigmoid mesocolon with associated tightening of the surrounding adipose tissue. Similar findings were also evident on magnetic resonance imaging, and fluorodeoxyglucose uptake was apparent on positron emission tomography CT. In light of the possibility of mesenteric carcinoid or other malignancy, laparoscopic sigmoid colectomy (with D3 lymph node dissection) was carried out at the same time as laparoscopic cholecystectomy. Pathological testing of the resected specimen showed estrogen receptor and progesterone receptor expression, and sigmoid mesocolon endometriosis was diagnosed. It is extremely rare for endometriosis lesions to arise in the mesentery. A case of endometriosis in the sigmoid mesocolon is presented, together with a discussion of the literature.

An 81-year-old woman presented with abdominal pain and bloody stool. She was diagnosed with ischemic colitis and referred to our hospital. Abdominal computed tomography showed a 35-mm tumor in the sigmoid colon. The tumor was not detected on colonoscopy, but fluorodeoxyglucose-positron emission tomography (FDG-PET) showed enhanced uptake. Because the possibility of malignant disease could not be ruled out, sigmoidectomy was performed. The histopathologic and immunohistochemical diagnosis was schwannoma of the colon, which is rare. Preoperative diagnosis is difficult for this type of submucosal tumor. Schwannoma presents with high uptake on FDG-PET scanning, but it is not malignant. Therefore, it is necessary to carefully consider the treatment strategy.

A 68-year-old man was diagnosed as having advanced sigmoid colon cancer with a bladder fistula. Preoperative neoadjuvant chemotherapy was performed to avoid anterior pelvic evisceration. Since the tumor shrank, totally laparoscopic radical resection was performed. The bladder fistula was resected full-thickness, using bilateral observation with a laparoscope and a cystoscope, which resulted in negative margins. The pathological findings were adenocarcinoma, T4b, N0, M0, yStage IIc ; all surgical margins were negative. Preoperative chemotherapy made it possible to preserve bladder function, reduce operative stress, and achieve a complete resection. A successful case of conversion laparoscopic surgery for advanced sigmoid colon carcinoma with a bladder fistula is reported.

A 67-year-old man visited a medical clinic complaining of right thigh pain in September 2018. CT and MRI examinations were performed with suspicion of lumbar spinal canal stenosis. Imaging showed the rectum penetrated by a cord-shaped foreign body between the upper rectum and sacrum. It was speculated that the symptoms were caused by the foreign body, because the tip of the foreign body was near the 2^nd sacral nerve. The patient was referred to our hospital for elective surgery, but his thigh pain got worse, so he was brought to the hospital by an ambulance in December. When examined in the emergency department, his general condition was good, afebrile, and no signs of peritoneal irritation. Colonoscopy disclosed a stick-shaped foreign body stuck into the wall of the rectum 15 cm proximal to the anus. Emergency surgery was performed with a diagnosis of penetration of the rectum by a foreign body. At laparoscopic surgery, the foreign body was removed and recognized as a toothpick. Postoperatively, his symptoms disappeared. He was unaware of the ingestion of the toothpick, but he had a habit of sleeping with the toothpick in his mouth. Rectal penetration by a toothpick with lower extremity symptoms is rare.

A 77-year-old man, who had a tumor in segment 8 of his liver, was diagnosed with hepatocellular carcinoma based on abdominal ultrasonography. The pathological diagnosis was well-differentiated hepatocellular carcinoma. One year after the first surgery, tumors in S2 and S3 appeared, and they were suspected tumors of hepatocellular carcinoma, whereas a tumor in S4 had high fluorodeoxyglucose uptake on positron emission tomography with ring enhancement. The tumors in S2 and S3 were subjected to radiofrequency ablation, and the tumor in S4 was partially resected. Histopathologically, the tumor in S4 was a combined hepatocellular carcinoma-cholangiocellular carcinoma. Two years after the first surgery, multiple recurrences in S3 of the liver and gastric lesser curvature lymph node metastasis were observed. The intrahepatic lesions were well controlled by chemotherapy 6 months after the initiation of lenvatinib treatment, but the gastric lesser curvature lymph node showed a tendency of enlargement, and surgical resection was performed. The pathological diagnosis was metastatic combined hepatocellular carcinoma-cholangiocellular carcinoma. Three years after the first hepatectomy, lenvatinib treatment is ongoing without recurrence.

We encountered a case in which multidisciplinary treatment of surgical resection and lenvatinib was effective for disease control in a patient with metachronous double cancer of hepatocellular carcinoma and combined hepatocellular carcinoma-cholangiocellular carcinoma.

A 77-year-old man complaining of abdominal pain was diagnosed with gallstone attack elsewhere and was referred to our hospital for the purpose of surgery. Contrast-enhanced CT and contrast-enhanced MRI scans revealed a calculus of 25 mm in size in the neck of the gallbladder, thickening of the wall confined to the bottom of the gallbladder, and aggregation of multilocular microcysts in the wall of the gallbladder. Laparoscopic cholecystectomy was performed under the diagnosis of cholelithiasis and gallbladder adenomyosis. Histopathological examination revealed the lesion at the bottom of the gallbladder to be mucinous cystadenoma. Although it is difficult to make a definitive diagnosis of this disease by image diagnosis alone, it should be considered as a possible differential diagnosis when multilocular cystic lesions are found in the gallbladder. Since there are reports of malignant transformation and jaundice symptoms due to intra-biliary progression, resection is considered necessary if this disease is suspected.

We report a rare case of carcinosarcoma of the gallbladder that mimicked acute hemorrhagic cholecystitis. An 86-year-old woman was referred to our hospital because of right upper quadrant pain that had presented the day before the referral. Enhanced computed tomography showed enlargement of the gallbladder, thickening of the gallbladder wall, a stone in the fundus, and a linear high-density area in the gallbladder lumen. The lumen showed heterogeneous hyperintensity on T2-weighted magnetic resonance imaging. The patient was diagnosed with acute hemorrhagic cholecystitis and underwent laparoscopic cholecystectomy. Macroscopically, the gallbladder was filled with a solid pedunculated tumor. Histologically, the tumor consisted of adenocarcinoma and sarcomatous tumor cells with cartilaginous tissue. Immunohistochemically, the sarcomatous elements tested negative for cytokeratin AE1/AE3 and positive for desmin and smooth muscle actin. Based on these findings, the patient was diagnosed with pure carcinosarcoma of the gallbladder. Considering her age, additional excision was not performed. She remains alive with no signs of recurrence 8 months after the surgery.

A 55-year-old woman with repeated vomiting after meals was admitted to our hospital. Dynamic computed tomography revealed unresectable pancreatic cancer obstructing the 3^rd portion of the duodenum and superior mesenteric vein and facing the abdominal aorta. She had a UGT1A1∗6/∗28 polymorphism, but she was relatively young, and her systemic condition was favorable. She received FOLFIRINOX therapy with dose reduction of irinotecan carefully, as well as pegfilgrastim prophylaxis to prevent severe neutropenia. She remains alive 2 years and 6 months after the initiation of chemotherapy.

A 20-year-old woman was examined at a local clinic for coughing and fever, and abdominal contrast-enhanced computed tomography (CT) showed massive splenomegaly. That night, she developed abdominal pain and went into shock. Abdominal contrast-enhanced CT showed pooling of blood throughout the entire peritoneal cavity, and hemorrhagic shock due to splenic rupture was diagnosed. Emergency laparotomy was performed, and it was found that the spleen was not anchored in the retroperitoneum, and the splenic vessels were twisted. Because persistent bleeding from the splenic capsule was observed, the organ was resected. The patient's postoperative course was uneventful, and she was discharged home on postoperative Day 18. Subsequent investigations showed that the splenomegaly was due to infectious mononucleosis (IM), and wandering spleen and splenic torsion were rare conditions. It was considered that the splenic torsion had decreased venous perfusion, resulting in one-way inflow via the splenic artery causing the spleen to increase in size and rupture. IM is a risk factor for splenic rupture due to splenomegaly, and in patients with wandering spleen, the possibility that the clinical course may be modified by torsion must be kept in mind.

We report the case of a 75-year-old man who was brought to our emergency room for a right incarcerated inguinal hernia. An emergency surgery revealed a firm mass and hypertrophy in the hernia sac and multiple nodules in the peritoneum. Malignant peritoneal mesothelioma was the final histological diagnosis. He chose not to receive chemotherapy. He did not undergo medical intervention for 5 months, although the disease gradually progressed, leading to worsening symptoms, such as abdominal distension and dullness. The patient finally chose to be treated with chemotherapy containing paclitaxel, which was administered weekly for 3 consecutive weeks followed by a one-week rest. After one course of administration, he refused to continue outpatient chemotherapy and chose to receive home-based medical care. Allowing his condition to increasingly worsen, he died 7 months postoperatively. We encountered a case of malignant peritoneal mesothelioma discovered during a surgery for a right incarcerated inguinal hernia.

A 58-year-old male patient visited our hospital with a chief complaint of right-sided lower abdominal pain. An abdominal CT scan revealed a 12 cm cystic mass in the pelvis, which did not intrude on the right ureter and common iliac artery and vein. We could not deny the possibility that it was a retroperitoneal malignant tumor that it was a retroperitoneal malignant tumor, so we performed a resection of the cystic mass. During the operation, we damaged the cyst wall and a considerable amount of brown colored fluid appeared from within the mass. The cyst wall was then completely resected. Pathological results indicated that the mass was a previously undiagnosed hematoma that had become encapsulated ; therefore, we diagnosed it as an idiopathic chronic expanding hematoma (CEH) in the retroperitoneal space. Here, we report a very rare case of retroperitoneal CEH with a review of the literature.

Here we report a case of the paracecal internal hernia into the inferior ileocecal recess. A 70-year-old woman with abdominal pain and nausea visited our hospital. Contrast-enhanced CT imaging revealed a ventrally-shifted cecum and a well-enhanced closed loop of the small intestine with mesentery in the dorsal space of the cecum. We diagnosed that she was suffering from a paracecal internal hernia and open surgery was performed. A 17 cm-long loop of incarcerated but viable ileum was found in the hernia orifice within the inferior ileocecal recess. We performed an appendectomy and opened the hernia orifice. There are four known types of recesses around the paracecal area : superior ileocecal recess, inferior ileocecal recess, retrocecal recess, and retro appendiceal recess. Meyer et al classified the paracecal hernia into four types : medial, lateral, retrocecal, and unclassifiable. The medial type of paracecal recess includes the superior ileocecal recess, inferior ileocecal recess, and retro appendiceal recess. While paracecal internal hernia of the retrocecal recess is frequently observed, the protrusion of this hernia into the inferior ileocecal recess is rare. To the best of our knowledge, this was the 6th case of paracecal internal hernia of the inferior ileocecal recess that was reported in Japan.

A 43-year-old man underwent open reduction and internal fixation (ORIF) of an acetabular fracture with an Ilioinguinal + Kocher Langenbeck approach. He developed a right inguinal hernia postoperatively and was treated with transabdominal preperitoneal (TAPP) repair two years after ORIF. The Ilioinguinal approach for ORIF of acetabular fractures is comprised of dissection of the floor of the inguinal canal and mobilization of the iliopsoas muscles and external iliac vessels extraperitoneal ; therefore, inguinal hernia is one of the potential postoperative complications of this procedure. Although we were concerned about the postoperative risk of extraperitoneal adhesions after a TAPP repair, a right direct inguinal hernia was found easily with laparoscopy and the peritoneal incision and dissection around the hernial site were completed without any complications. We needed to be careful around Cooper's ligament and the external iliac vessels in order to reduce the risk of postoperative adhesions. We were able to place and fix the mesh appropriately and close the peritoneal flaps. TAPP appeared to be a beneficial treatment for an inguinal hernia that develops after ORIF for an acetabular fracture.