Robotic-assisted retroperitoneal lymph node dissection for stage II testicular cancer

Objective:To evaluate the perioperative as well as early oncological outcomes of patients undergoing robotic retroperitoneal lymph node dissection for treatment of testicular cancer.Methods:We conducted a prospective consecutive case series of patients undergoing robotic assisted retroperitoneal lymph node dissection for metastatic testicular cancer between May 2018 and July 2021 at our institution.Data were collected on patient and tumour characteristics,intraoperative and postoperative parameters,and functional and oncological outcomes.Descriptive statistics are presented.Results:Nineteen patients were identified;18(94.7%)completed the procedure robotically and one was converted to open surgery;78.9%of patients had stage≥IIB and 12(63.2%)patients had undergone prior chemotherapy.The median operative time was 300(interquartile range[IQR]240-315)min.Median blood loss was 100(IQR 50-175)mL.Median length of stay was 2(range 1-11)days.All robotically completed patients commenced diet and passed flatus on Day 1 and were discharged by Day 3.The median lymph node yield was 40.5(IQR 38-51)nodes.All patients undergoing nerve-sparing procedures recovered antegrade ejaculatory function.One patient had a Clavien-Dindo III complication(chylous ascites requiring drainage).At a median follow-up of 22.3(IQR 16.3-24.9)months,one patient developed retroperitoneal recurrence,which was successfully treated with second-line chemotherapy;no other patients have had recurrences.Conclusion:Robotic retroperitoneal lymph node dissection is a safe and feasible alternative to open surgery in appropriately selected patients,offering low morbidity.Early oncological outcomes are promising.Larger cohorts and longer follow-ups are required to validate our institution's findings.

Retroperitoneal bronchogenic cyst:A case report and review of literature

BACKGROUND Bronchogenic cysts are rare developmental anomalies that belong to the category of congenital enterogenous cysts.They arise from lung buds and are present at birth.The embryonic foregut is their origin.Typically,they are located within the chest cavity,particularly in the cavum mediastinale of the thoracic cavity or lodged in the pulmonary parenchyma,and are considered a type of lung bud malformation.CASE SUMMARY A 49-year-old male patient was admitted to the hospital due to the detection of a retroperitoneal mass during a physical examination.Two weeks before admission,the patient underwent a physical examination and routine laboratory tests,which revealed a space-occupying mass in the retroperitoneal region.The patient did not report any symptoms(such as abdominal pain,flatulence,nausea,vomiting,high fever,or chills).The computed tomography(CT)revealed a retroperitoneal spaceoccupying lesion with minimal enhancement and a CT value of approximately 36 Hounsfield units.The lesion was not delineated from the boundary of the pancreatic body and was closely related to the retroperitoneum locally.CONCLUSION Following a series of tests,an abdominal mass was identified,prompting the implementation of a laparoscopic retroperitoneal mass excision procedure.During the investigation,an 8 cm×7 cm cystic round-shaped mass with a distinct demarcation was identified in the upper posterior region of the pancreas.Subsequently,full resection of the mass was performed.Postoperative pathological examination reveled a cystic mass characterized by a smooth inner wall.The cystic mass was found to contain a white,viscous liquid within its capsule.

Giant retroperitoneal hemolymphangioma:A case report and review of literature

BACKGROUND Hemolymphangioma is a very rare benign tumor in clinical practice caused by abnormalities of the vasculature.Its clinical features are often atypical,and it is easy to miss and misdiagnose.When the time of nuclear magnetic T1 is significantly reduced,the diagnosis of hemangioma should be considered.Therefore,we report this case in the hope of raising clinicians'awareness of the disease.CASE SUMMARY A 37-year-old man presented with a giant retroperitoneal hemolymphangioma.Computed tomography and magnetic resonance imaging indicated the possibility of a large perirenal lymphatic cyst.The postoperative pathological diagnosis is retroperitoneal hemolymphangioma.The patient underwent surgical excision after adequate drainage.The postoperative recovery was smooth and there were no complications.There was no recurrence during half a year of follow-up.CONCLUSION This case reiterates that large retroperitoneal cystic masses with significantly shortened nuclear T1 time should be considered hemolymphangioma.Specific clinical basis and experience for the diagnosis and treatment of these diseases is necessary.

The Value of MRI and CT in the Diagnosis of Retroperitoneal Tumours

Objective:This study aimed to investigate the effectiveness and value of MRI and CT in the diagnosis of retroperitoneal tumours.Methods:60 patients with retroperitoneal tumours admitted to our hospital between July 2022 and March 2023 were selected as the study subjects.All of them received MRI and CT examinations.The detection of the two examination methods was compared and analyzed using the pathological findings as the standard.Results:The detection rate of MRI(58/60,96.67%)was significantly higher than that of CT(50/60,83.33%),and the difference was significant(P=0.015<0.05).Conclusion:Both MRI and CT have important application values in the diagnosis of retroperitoneal tumours.MRI has advantages in observing soft tissue structures,nerve tissues,etc.,and can provide more detailed anatomical structure information,which can help differentiate the retroperitoneal tumours and locate them accurately.CT,on the other hand,has unique advantages in observing the skeletal structure and the density of certain tumours,etc.It can quickly obtain comprehensive imaging information,which helps to determine the extent and invasion of the tumour.

Unilateral post-chemotherapy robot-assisted retroperitoneal lymph node dissection in Stage II non-seminomatous germ cell tumor:A tertiary care experience

Objective Post-chemotherapy retroperitoneal lymph node dissection(PC-RPLND)represents an integral component of the management of patients with non-seminomatous germ cell tumor(NSGCT).Modified templates have been proposed to minimize the surgical morbidity of the procedure.Moreover,the implementation of robotic surgery in this setting has been explored.We report our experience with unilateral post-chemotherapy robot-assisted retroperitoneal lymph node dissection(PC-rRPLND)for clinical Stages IIA and IIB NSGCTs.Methods A retrospective single institution review was performed including 33 patients undergoing PC-rRPLND for Stages IIA and IIB NSGCTs between January 2015 and February 2019.Following orchiectomy,patients were scheduled for chemotherapy with three cycles of bleomycin-etoposide-cisplatin.Patients with a residual tumor of<5 cm and an ipsilateral metastatic disease on pre-and post-chemotherapy CT scans were eligible for a unilateral template in absence of rising tumor markers.Descriptive statistics were provided for demographics,clinical characteristics,intraoperative and postoperative parameters.Perioperative,oncological,and functional outcomes were recorded.Results Overall,7(21.2%)patients exhibited necrosis or fibrosis;14(42.4%)had mature teratoma;and 12(36.4%)had viable tumor at final histology.The median lymph node size at surgery was 25(interquartile range[IQR]21-36)mm.Median operative time was 180(IQR 165-215)min and no major postoperative complications were observed.Anterograde ejaculation was preserved in 75.8%of patients.Median follow-up was 26(IQR 19-30)months and a total of three recurrences were recorded.Conclusion PC-rRPLND is a reliable and technically reproducible procedure with safe oncological outcomes and acceptable postoperative ejaculatory function in well selected patients with NSGCTs.

The application of internal suspension technique in retroperitoneal robot-assisted laparoscopic partial nephrectomy with a new robotic system KangDuo Surgical Robot-01:Initial experience

Objective To assess the feasibility of internal suspension technique in retroperitoneal robot-assisted laparoscopic partial nephrectomy(rRAPN)with a new robotic platform called KangDuo Surgical Robot-01(KD-SR-01)system(Suzhou KangDuo Robot Co.,Ltd.,Suzhou,China)and discuss its surgical technique.Methods A 44-year-old male patient was admitted with a 2.5 cm tumor on dorsolateral upper pole of the left kidney.The R.E.N.A.L.nephrometry score of this patient was 4x.This patient underwent rRAPN with KD-SR-01.The perinephric fat between the tumor and Gerota's fascia was preserved,which was used for internal suspension traction during tumor resection.Postoperative follow-up data were collected.Results The surgery was successfully carried out with a duration of 127 min,in which the docking time was 6 min 25 s and console time was 60 min.The warm ischemia time was 19 min 53 s,and the estimated blood loss was 0 mL.The pathological histology showed a pathological tumor stage 1a clear cell renal cell carcinoma,with a negative surgical margin.The World Health Organization/International Society of Urological Pathology(WHO/ISUP)grade of this patient was Grade 2.No recurrence was observed during the 6-month follow-up.Conclusion Internal suspension in rRAPN is feasible and effective with use of the new robotic system KD-SR-01.

Retroperitoneal cavernous hemangioma misdiagnosed as lymphatic cyst:A case report and review of the literature

BACKGROUND Primary abdominal and retroperitoneal cavernous hemangioma is a vascular tumor and rarely seen in the clinic.Due to the lack of specific imaging features,retroperitoneal cavernous hemangioma cannot be diagnosed accurately.Some symptoms may develop with the enlargement of lesion volume or the occurrence of complications such as rupture or oppression.We report here a special case who was admitted with chronic abdominal pain.Admission examination suggested a retroperitoneal lymphatic duct cyst.Laparoscopic resection of the retroperitoneal mass was performed,and histological examination confirmed retroperitoneal cavernous hemangioma.CASE SUMMARY The patient was a 43-year-old Tibetan woman with intermittent left lower abdominal pain and discomfort 3 years ago.Ultrasonography revealed a cystic mass in the retroperitoneum with clear boundaries,internal septa,and no blood flow signal.Computed tomography(CT)and magnetic resonance imaging(MRI)showed an irregular space-occupying mass in the retroperitoneum,and retroperitoneal lymphatic cyst was considered.Plain CT scanning showed multiple cystlike hypo-intense shadows in the retroperitoneum,partially fused into a mass,and no obvious enhancement was found on enhanced scanning.MRI showed multiple irregular clump-like long T1 and long T2 signal shadows above the pancreas,within which linear short T2 signal shadows were seen.Diffusionweighted imaging sequence showed hypo-signal shadows,without obvious enhancement on enhanced scanning.Ultrasound,CT,and MRI all suggested the possibility of retroperitoneal lymphatic cyst.However,the patient was finally diagnosed with retroperitoneal cavernous hemangioma by pathological examination.CONCLUSION Retroperitoneal cavernous hemangioma is a benign lesion,and it is difficult to make a diagnosis preoperatively.Surgical resection may be the only treatment,which not only allows histopathological confirmation as a diagnostic purpose and excludes any risk of malignancy,but also avoids invasion of adjacent tissues,oppression,and other complications as a therapeutic goal.

Retroperitoneal and abdominal bleeding in anticoagulated COVID-19 hospitalized patients:Case series and brief literature review

BACKGROUND Hospitalized and severely ill coronavirus disease 2019(COVID-19)patients necessitate prophylactic or therapeutic anticoagulation to minimize the risk of thrombosis at different sites.Life-threatening bleeding complications include spontaneous iliopsoas hematoma,peritoneal bleeding,and extra-abdominal manifestations such as intracranial hemorrhage.CASE SUMMARY Bleeding in the abdominal wall results in less severe complications than seen with iliopsoas hematoma or peritoneal bleeding.In our case series of 9 patients,we present retroperitoneal and abdominal bleeding complications following anticoagulation in hospitalized COVID-19 patients with severe acute respiratory syndrome coronavirus 2 pneumonia.Contrast-enhanced computed tomography(CE-CT)is the best imaging modality for assessing hematoma secondary to anticoagulation and determines the therapeutic approach,whether interventional,surgical,or conservative management.CONCLUSION We present the role of CE-CT for rapid and precise localization of the bleeding site and prognostic counseling.Finally,we provide a brief review of the literature.

IgG4-related kidney disease complicated with retroperitoneal fibrosis:A case report

BACKGROUND IgG4-related disease(IgG4-RD)is a chronic fibrotic disease mediated by immunity recognized by clinicians in recent years.When the kidney is involved,it is called IgG4-related kidney disease(IgG4-RKD).IgG4-related tubulointerstitial nephritis(IgG4-TIN)is a representative manifestation of IgG4-RKD.IgG4-TIN can cause obstructive nephropathy complicated by retroperitoneal fibrosis(RPF).Cases of IgG4-TIN complicated with RPF are rare.Glucocorticoids are the firstline therapeutic medication for IgG4-RD and can significantly improve renal function.CASE SUMMARY Herein,we report the case of a 56-year-old man with IgG4-RKD complicated with RPF.The patient presented to the hospital with complaints of elevated serum creatinine(Cr),nausea,and vomiting.During hospitalization,Cr was 1448.6μmol/L,and serum IgG4 was increased.A total abdominal computed tomography(CT)scan and enhanced CT scan obviously indicated RPF.Although this patient had a long course and renal insufficiency,we performed a kidney biopsy.Renal biopsy showed that the renal tubulointerstitium had focal plasma cell infiltration and increased lymphocyte infiltration accompanied by fibrosis.After combining the biopsy results with immunohistochemistry,it was found that the absolute number of positive IgG4+cells per high power field exceeded 10,and the ratio of IgG4/IgG was over 40%.Finally,the patient was diagnosed with IgG4-TIN complicated with RPF and given glucocorticoids as long-term maintenance therapy,helping him keep out of dialysis.After a follow-up of 19 mo,the patient had recovered well.Previous literature on IgG4-RKD and RPF was retrieved from PubMed to characterize the clinical and pathological features and to identify the diagnosis and treatment of IgG4-RKD.CONCLUSION Our case report demonstrates the clinical characteristics of IgG4-RKD complicated with RPF.Serum IgG4 is a favorable indicator for screening.Performing renal biopsy actively plays a vital role in diagnosis and treatment,even if the patient has a long course and manifests with renal insufficiency.It is remarkable to treat IgG4-RKD with glucocorticoids.Hence,early diagnosis and targeted therapy are essential for reversing renal function and improving extrarenal manifestations in patients with IgG4-RKD.

Clinical Experience of Primary Retroperitoneal Tumor: Report of 600 Cases

Objective： To summarize the experience of management for primary retroperitoneal tumor （PRPT） and to analyze the factors influencing the outcome after operation. Methods： The data of 600 cases of PRPT in General Hospital of PLA were reviewed retrospectively. Results： Of 600 cases of PRPT, 546 were surgically treated. Among theme 369 were malignant and 177 benign. 366 cases were followed up for 1 month to 15 years. The 1-years 3-year, and 5-year survival rate in the patients subject to complete resection was 90.5%, 73.2% and 53.6%, respectively, and that in incomplete resection patients was 70.6%, 32.0%, 5.7% respectively （P〈0.01）. The Cox multi-various regression analysis revealed showed completeness of tumor resection, sex and histologic type were associated closely with local recurrence. Conclusion： Sufficient preoperative preparation and complete tumor resection play important roles for reducing recurrence and improving survival.

Clinical Analysis of 81 Cases of Benign Retroperitoneal Schwannoma

Objective： To analyze the clinical manifestations of retroperitoneal schwannoma in order to improve the diagnosis and treatment of this rare disease. Methods： Between January 1951 and September 2004, 81 patients with retroperitoneal schwannoma were retrospectively analyzed. Results： All cases received operative therapy. Sixty cases （74.1%） received a total resection; 12 cases （14.9%） subtotal resection, and 9 cases （11.1%） exploration. During the surgical operation, a single tumor was found in 77 cases （95.1%）, and multiple tumors in 4 cases （4.9%）. Most of the retroperitoneal schwannomas located beside the spine. The tumor was a fusiform, round or oval mass that was sharply circumscribed and encapsulated. Pathologic results showed all 81 cases were benign schwannoma. In the 4 cases of multiple tumors, 2 （2.5%） were diagnosed as double-primary tumors associated with ascending colon adenocarcinoma and lung squamous-cell cancer. One case recurred postoperatively. Conclusion： Retroperitoneal schwannoma was rare and preoperative diagnosis was difficult. Most of retroperitoneal schwannoma were benign and the surgical treatment was the first choice.

Retroperitoneal fibrosis: A rare cause of both ureteral and small bowel obstruction

Retroperitoneal fibrosis (RPF) is a rare condition of unclear etiology. It can cause ureteral obstruction. We present the unique case of a 54 years old female, who initially presented with spontaneous perforation of the cecum. Upon exploring the abdomen, the classical glistening white, unyielding retroperitoneal fibrosis was encountered. A right hemicolectomy was performed. Subsequently, the patient presented with bilateral ureteral obstruction, and later on with small bowel obstruction. Ureteral obstruction was treated with stents, and small bowel obstruction was treated with bypass. To our knowledge no case of idiopathic RPF presenting with features of both bilateral ureteral and small bowel obstruction has been reported in the literature.

Giant retroperitoneal lipoma presenting with abdominal distention:A case report and review of the literature

BACKGROUND Retroperitoneal lipomas are extremely rare tumors and tend to be large in size(>10 cm)when diagnosed,causing various clinical manifestations.Preoperative diagnosis of retroperitoneal lipomas is difficult.There is a lack of relevant information about the management and prognosis of these benign tumors due to limited reports.CASE SUMMARY A 53-year-old woman who complained about progressive abdominal distention and aggravating satiety was referred to the gynecological outpatient department of Peking Union Medical College Hospital.Computerized tomography(CT)revealed an immense mass with fat density,measuring 28.6 cm×16.6 cm in size.Adjacent organs,including the intestinal tract and uterus,were squeezed to the right side of the abdomen.An exploratory laparotomy was performed with suspicion of liposarcoma.Intraoperatively,a giant yellowish lobulated mass was found occupying the retroperitoneum and it was removed by tumor debulking.Postoperative histopathological results confirmed the diagnosis of retroperitoneal lipoma.CONCLUSION Retroperitoneal lipoma is a very rare condition and is difficult to differentiate from well-differentiated liposarcoma.Radiographic investigations,especially CT and magnetic resonance imaging,are important for preoperative diagnosis.Surgical resection is the fundamental treatment,which is difficult due to its size and relation to neighboring structures.

Giant retroperitoneal liposarcoma treated with radical conservative surgery: A case report and review of literature

BACKGROUND Retroperitoneal liposarcoma(RLPS)is a rare malignant tumor of the connective tissue and usually grows to a large size,undetected.Diagnosis is currently based on collective findings from clinical examinations and computed tomography(CT)and magnetic resonance imaging,the latter of which show a fat density mass and possible surrounding organ involvement.Surgical resection is the main therapeutic strategy.The efficacy and safety of further therapeutic choices,such as chemotherapy and radiotherapy,are still controversial.CASE SUMMARY A 61-year-old man presented with complaint of a large left inguinal mass that had appeared suddenly,after a slight exertion.Ultrasonography revealed an omental inguinal hernia.During further clinical examination,an enormous palpable abdominal mass,continuing from the left inguinal location,was observed.CT revealed a giant RLPS,with remarkable mass effect and wide visceral dislocation.After multidisciplinary consultation,surgical intervention was performed.Subsequent neoadjuvant chemotherapy and radiotherapy were precluded by the mass’large size and retroperitoneal localization,features typically associated with non-response to these types of treatment.Instead,the patient underwent conservative treatment via radical surgical excision.After 1 year,his clinical condition remained good,with no radiological signs of recurrence.CONCLUSION Conservative treatment via surgery resulted in a successful outcome for a large RLPS.

Retroperitoneal fibrosis associated with immunoglobulin G4-related disease

Retroperitoneal fibrosis is a rare disease characterized by the development of inflammation and fibrosis in the soft tissues of the retroperitoneum and other abdominal organs.Retroperitoneal fibrosis can be of 2 types:idiopathic and secondary.The recently advocated concept and diagnostic criteria of immunoglobulin G4(IgG4)-related disease,derived from research on autoimmune pancreatitis(AIP),has led to widespread recognition of retroperitoneal fibrosis as a condition caused by IgG4-related disease.We now know that previously diagnosed idiopathic retroperitoneal fibrosis includes IgG4-related disease;however,the actual prevalence is unclear.Conversely,some reports on AIP suggest that retroperitoneal fibrosis is concurrently found in about 10% of IgG4-related disease.Because retroperitoneal fibrosis has no specific symptoms,diagnosis is primarily based on diagnostic imaging(computed tomography and magnetic resonance imaging),which is also useful in evaluating the effect of therapy.Idiopathic retroperitoneal fibrosis can occur at different times with other lesions of IgG4-related disease including AIP.Thus,the IgG4 assay is recommended to diagnose idiopathic retroperitoneal fibrosis.High serum IgG4 levels should be treated and monitored as a symptom of IgG4-related disease.The first line of treatment for retroperitoneal fibrosis is steroid therapy regardless of its cause.For patients with concurrent AIP,i.e.,IgG4-related retroperitoneal fibrosis,the starting dose of steroid is usually 30-40 mg/d.The response to steroid therapy is generally favorable.In most cases,the pancreatic lesion and retroperitoneal fibrosis improve after the initial treatment.However,the epidemiology,treatment for recurring retroperitoneal fibrosis,and long-term prognosis are still largely unknown.Further analysis of such cases and research are necessary.

Surgical management of 143 patients with adult primary retroperitoneal tumor

AIM： To analyze the surgical management of adult primary retroperitoneal tumors （APRT） and the factors influencing the outcome after operation. METHODS： Data of 143 cases of APRT from 1990 to 2003 in the First Affiliated Hospital of China Hedical University were evaluated retrospectively. RESULTS： A total of 143 cases of APRT were treated surgically. Among them, 122 （85.3%） underwent complete resection, 16 （11.2%） incomplete resection, and 3 （3%） surgical biopsies. Twenty-nine （20.2%） underwent tumor resection plus multiple organ resections. Ninety-five malignant cases were followed up for 1 mo to 5 years. The 1-year, 3-year, and 5-year survival rates of the patients subject to complete resection was 94.9%, 76.6% and 34.3% and that of patients with incomplete resection was 80.4%, 6.7%, and 0%, respectively （P 〈 0.001）. The Cox multi-various regression analysis showed the completeness of tumor, sex and histological type were associated closely with local recurrence. CONCLUSION： Sufficient preoperative preparation and complete tumor resection play important roles in redudng recurrence and improving survival.

Three cases of retroperitoneal schwannoma diagnosed by EUS-FNA

Schwannomas are peripheral nerve tumors that are typically solitary and benign.Their diagnosis is largely based on surgically resected specimens.Recently,a number of case reports have indicated that retroperitoneal schwannomas could be diagnosed with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).We report the diagnosis of three cases of schwannoma using EUS-FNA.Subjects were two males and one female,ages 22,40,and 46 years,respectively,all of whom were symptom-free.Imaging findings showed well-circumscribed round tumors.However,as the tumors could not be diagnosed using these findings alone,EUS-FNA was performed.Hematoxylin-eosin staining of the resulting tissue fragments revealed bland spindle cells with nuclear palisading.There was no disparity in nuclear sizes.Immunostaining revealed S-100 protein positivity and all cases were diagnosed as schwannomas.Ki-67 indexes were 3%-15%,2%-3%,and 3%,respectively.No case showed any signs of malignancy.As most schwannomas are benign tumors and seldom become malignant,we observed these patients without therapy.All tumors demonstrated no enlargement and no change in characteristics.Schwannomas are almost always benign and can be observed following diagnosis by EUS-FNA.

Retroperitoneal Versus Transperitoneal Laparoscopic Partial Nephrectomy: A Systematic Review and Meta-analysis

Objective To review published literatures comparing the safety and effectiveness of retroperitoneal laparoscopic partial nephrectomy(RLPN) with transperitoneal laparoscopic partial nephrectomy(TLPN) and provide reference for clinical work. Methods The search strategy was performed to identify relevant papers from the Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, Google Scholar, China Hospital Knowledge Database, Wangfang Chinese Periodical Database, and VIP Chinese Periodical Database. All papers comparing RLPN with TLPN were included from 2000 to 2015. Two to three reviewers independently screened, evaluated, and extracted the included papers. A Meta-analysis was executed by using Review Manager 5.3 software. The interesting outcomes were tumor size, operating time, estimated blood loss, warm ischaemia time, length of hospital stay, positive margin rate, open conversion rate, overall complication rate, and recurrence rate. Results The literature search obtained 378 papers, then 10 of them were ultimately met the inclusion criteria and included in the systematic review. Finally, 6 of the 10 papers were included in the Meta-analysis. RLPN had significantly less operating time [P = 0.01, mean difference(MD)=-33.68, 95% confidence interval(CI) within(-60.35,-7.01)] and shorter length of hospital stay [P < 0.0001, MD=-1.47, 95% CI within(-2.18,-0.76)] than TLPN. Significant differences were not found between RLPN and TLPN in other outcomes. Conclusions RLPN may be equally safe and be faster than TLPN. Each center can choose a modality according to your own operating habits and experience.

Autoimmune pancreatitis metachronously associated with retroperitoneal fibrosis with IgG4-positive plasma cell infiltration

Retroperitoneal fibrosis is an uncommon disorder characterized by the formation of a dense plaque of fibrous tissue in the retroperitoneum, and its etiology remains unknown. Autoimmune pancreatitis is a rare type of chronic pancreatitis characterized by fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis in the pancreas. We present a case of autoimmune pancreatitis that developed 10 mo after the occurrence of retroperitoneal fibrosis. Histological findings of the resected retroperitoneal mass were marked periureteral fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis. These findings suggest a common pathophysiological mechanism for retroperitoneal fibrosis and autoimmune pancreatitis in this case. Some cases of retroperitoneal fibrosis might be a retroperitoneal lesion of IgG4-related sderosing disease.

Unicentric Castleman disease presenting as a retroperitoneal peripancreatic mass:A report of two cases and review of literature

Castleman disease(CD) is a rare disorder of lymph nodes and related tissues. CD generally occurs in the mediastinum, as well as in cervical, retroperitoneal and axillary regions. The disease is classified into two major types: unicentric CD(UCD) and multicentric CD. The occurrence of UCD in the retroperitoneal peripancreatic region is quite rare. We encountered two cases of retroperitoneal peripancreatic UCD in our hospital during the past three years. Following a series of medical examinations, including magnetic resonance imaging, computed tomography, ultrasonography and postoperative histopathological examination, these two patients were diagnosed with UCD,which presented as a retroperitoneal peripancreatic mass.The mass in each patient was completely excised,and no postoperative radiochemotherapy was administered.Both patients recovered well without recurrence during a follow-up period of 30 mo and 8 mo.