Evaluation of CT findings for the differentiation of benign from malignant primary retroperitoneal tumors

Background Benign and malignant primary retroperitoneal tumors （RT） have different pathological manifestations,and overlapping imaging characteristics.This study aimed to evaluate the value of computed tomography （CT） for differentiating benign from malignant RT.Methods One hundred and ninety-four patients with clinical and radiographic data were evaluated retrospectively following surgical resection of primary RT.There were 38.1％ （n=74） benign lesions and 61.9％ （n=120） malignant lesions.Categorical variables were tested with a chi-square test or Fisher＇s exact test for the diagnostic indexes and sensitivity and specificity of CT characteristics.Results In univariate analysis,the differences in ill-defined margins,irregular surfaces,long diameter ＞6.75 cm,short diameter ＞6.25 cm,and solid or mixed texture had statistical significance; the sensitivity and specificity were 44.2％ and 91.9％,70.0％ and 62.2％,68.8％ and 60.7％,59.7％ and 74.2％,87.5％ and 35.1％,respectively.In multivariate analysis,a combination of all the above indexes was the best model for differentiating malignant tumors,resulting in the most accurate diagnosis of malignancies with a sensitivity of 77.2％ and a specificity of 81.1％ （P＜0.0001） when the score was 4.The differences in other findings including CT attenuation,number,and calcification had no statistical significance.The unique characteristics included the spotted enhancement （mottled high density）in schwannoma （P＜0.0001）,adipose tissue in liposarcoma （P＜0.0001）and paravertebral location in neurogenic tumors （P＜0.0001）.Conclusions More accurate differential diagnosis of primary RT can be made through comprehensive analysis of the combined diagnostic indexes of CT.Some specific characteristics of CT can assist in preoperative planning.

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.

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.

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.

Ectopic hepatocellular carcinoma mimicking a retroperitoneal tumor:A case report

BACKGROUND An ectopic hepatocellular carcinoma(EHCC)arises from the ectopic liver which is defined as a hepatic organ or tissue not connected to surrounding tissues.EHCC is a rare disease and it is difficult to diagnose preoperatively.Furthermore,the clinical features are not fully elucidated.CASE SUMMARY A retroperitoneal tumor(6 cm)was located at the dorsal side of the pancreas head on abdominal ultrasonography in an 81-year old woman positive for hepatitis C virus antibody.Contrast enhanced-computed tomography and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging showed viable HCC patterns with early enhancement and delayed washout.The tumor markers-serum alphafetoprotein and alpha-fetoprotein-L3%-were increased to 30.1 ng/m L and83.1%,respectively.Protein induced by vitamin K absence or antagonist-Ⅱwas within normal levels(17 m AU/m L).Positron emission tomography-computed tomography showed strong accumulation into the tumor(Standardized Uptake Value max:13.8),and the tumor cytology following endoscopic ultrasoundguided fine needle aspiration showed poorly differentiated carcinoma.Tumor extirpation was performed,and operative findings showed that the retroperitoneal tumor was disconnected from the pancreas and the liver.Swollen lymph nodes near the tumor were histologically normal.On histological examination,the tumor was finally diagnosed as EHCC with Arginase-1 positive expression.CONCLUSION We report our experience of a rare EHCC which was difficult to diagnose,and we present a review of the literature.

A Case of Large “Silent” Extra-adrenal Retroperitoneal Paraganglioma Resected Laparoscopically

SILENT extra-adrenal retroperitoneal paragangliomas (PGLs) arise from dispersed paraganglias which tend to be symmetrically distributed in close relation to the aorta and sympatheticnervous system. They are rarely encountered in everyday surgical practice.

Retroperitoneal congenital epidermoid cyst misdiagnosed as a solid pseudopapillary tumor of the pancreas:A case report

BACKGROUND Retroperitoneal cysts are rare and usually asymptomatic abdominal lesions.Epidermoid cysts are frequent benign cutaneous tumors,but retroperitoneal localization of these cysts does not occur very often.CASE SUMMARY We report a case report of a 25-year-old woman with a giant mass in the abdominal cavity.Because imaging examination indicated that the mass probably originated from the pancreas,the mass was considered a solid pseudopapillary tumor of the pancreas(SPTP).However,surgery revealed a retroperitoneal epidermoid cyst located behind the pancreas neck and the root of the superior mesenteric artery(SMA).We performed complete resection of the tumor.Postoperative pathology showed an epidermoid cyst.The patient fared well after two months of follow-up.CONCLUSION Surgery is the gold standard for the diagnosis and treatment of retroperitoneal epidermoid cysts.Retroperitoneal epidermoid cysts around the pancreas are easily misdiagnosed as cystic SPTPs.Surgeons should pay particular attention to preoperative diagnosis to reduce severe surgical complications and improve the quality of life of patients.

Observation of the therapeutic efficacy of stereotactic radiotherapy in 44 cases of retroperitoneal metastatic tumor

Objective: To investigate the therapeutic effects of stereotactic radiotherapy for retroperitoneal metastatic tumor. Methods: From August 1997 to October 2004, 44 patients with retroperitoneal metastatic tumors were treated with stereotactic radiotherapy. The planning target volume was encompassed by 90%–95% isodose line. Fractional dose was from 6 Gy to 8 Gy, and they were treated 2–3 times per-week and 4–8 times in all. The total radiation doses of PTV were from 32 Gy to 48 Gy. Re- sults: After the radiotherapy, the pain was obviously relieved in 81.8% patients. Three months after completion of radiotherapy passed and then, abdominal CT was performed to evaluate the results. The whole effective rate was 81.8% [CR 27.7% (12/44) and PR 54.5% (24/44)], and six months after radiotherapy, CR was 27.7% (12/44) and PR was 59.1% (26/44). The middle survival time was 12 months. Conclusion: It is suggested that stereotactic radiotherapy for retroperitoneal metastatic tumor is a safe and effective method.

A Rare Retroperitoneal Mass:Leiomyosarcoma of the Inferior Vena Cava

Leiomyosarcoma of the inferior vena cava (IVC) is a rare soft tissue tumor, mesenchymal in origin that arises from smooth muscles of tunica media;it accounts for about 0.5% of all soft tissue sarcomas, and it is the commonest vascular leiomyosarcoma. The tumor progression is slow, and it is asymptomatic until advanced stage in which involvement of surrounding structures even when the symptoms present are nonspecific. Presentation of Case: A 60 years old lady presented with upper abdominal pain for 3 months duration. Past surgical history was significant for Hysterectomy 15 years ago. On examination: soft abdomen, palpable non pulsating right hypochondrial mass. Ultrasound of the abdomen showed tumor of the head of pancreas. CT scan showed large retroperitoneal tumor extending from the head of pancreas to IVC. Trans abdominal CT guided FNAC showed retroperitoneal sarcoma while Immunohistochemistry (IHC) was proved to be Leiomyosarcoma of the IVC. Discussion: Leiomyosarcoma of inferior vena cava (IVC) is a rare soft tissue tumor, mesenchymal in origin that arises from smooth muscles of tunica media;it accounts for about 0.5% of all soft tissue sarcomas, and it is the commonest vascular leiomyosarcoma. The type of surgical management is a matter of debate and includes resection alone, primary repair/cavoplasty, or replacement with a graft. Reconstruction of the IVC is not always required especially in chronic occlusions. Conclusion: Despite all the advanced modalities, surgery remains the most effective method for treatment of Leiomyosarcoma.

Surgical operation of a massive retroperitoneal tumor

Summarize the surgical cooperation of a massive retroperitoneal tumor. The main surgical cooperation points include: clos e observation of the patient's vital signs and condition changes, strengthen ing the prevention of potential complications, mak ing full preoperative preparation, master ing the coordination points of hand washing, itinerant nurses, and effective massive bleeding treatment plan, etc. Through perfect surgical cooperation and nursing, the patient's condition was stable and discharged smoothly.

Combined use of retroperitoneal laparoscopy and bladder resectoscope to treat renal and ureteral tumor occurring at the same side of transplanted kidney (report of 5 cases)

To evaluate the operative characteristics and efficacy of retroperitoneoscopic resection of renal,ureter and partial bladder for the treatment of native renal pelvic and ureteral transitional cell cancer occurring at the same side of transplanted kidney.Methods In 5 cases of renal transplantation,there were 2 cases of right native renal pelvic cancer,1 case of right native renal pelvic and ureter cancer and 2 cases of right ureter cancer respectively.The transplanted kidney was in the same iliac fossa side of the tumor.All 5 patients were subjected to nephroureterectomy and bladder cuff excision by retroperitoneoscopic technique.Results Five operations were completed successfully.The operative time was 180 to 280 min,and the blood loss was 50 to 200 ml.The recovery of intestinal function after operation was 12 to 36 h.The urine output was 1 500 to 4 000 per day.Postoperative serum creatinine was still normal.The mean hospital stay after operation was 4.5 days.Conclusion Retroperitoneal laparoscopic nephroureterectomy and bladder cuff excision is a good method to treat the native renal pelvic and ureteral transitional cell cancer occurring at the same side of transplanted kidney.The procedure is safe and less invasive,which provides a good protection of transplanted kidney.12 refs.

Solitary fibrous tumor:A case report of this multifaceted tumor

BACKGROUND Solitary fibrous tumor(SFT)is a remarkably uncommon mesenchymal tumor.STAT6 level and a combination of clinical,pathological,and molecular features are required to arrive at a proper diagnosis.CASE SUMMARY In this report,we present an intriguing case involving a 43-year-old woman who initially exhibited symptoms of a bleeding retroperitoneal tumor,initially resembling a gastrointestinal stromal tumor,but later confirmed as an SFT.However,a year later,what was initially believed to be a recurrence of her SFT was instead identified as a desmoid tumor.CONCLUSION Distinguishing SFT from other tumors was pivotal.Correcting misdiagnoses of tumor type initially and of recurrence later was necessary for appropriate treatment of the correct desmoid type.

Resection of the uncinate process of the pancreas due to a ganglioneuroma

A 33-year-old woman who presented with epigastric discomfort and diarrhea underwent an abdominal ultrasound(US).This investigation and subsequent contrastenhanced computed tomography,magnetic resonance imaging and endoscopic US with fine needle aspiration (FNA)revealed a 40 mm well-circumscribed mass in the uncinate process of the pancreas.Findings were suggestive of a mucinous or solid-cystic pseudopapillary tumor of the pancreas,although other lesions such as a nonfunctioning neuroendocrine tumor could not be ruled out.FNA samples were negative for malignant cells,but of limited value due to poor cellularity.It was decided to surgically remove the tumor because malignancy could not be discounted.Multiple intraoperative biopsies were suggestive of mesenchymal tumor and consequently a conservative resection(uncinatectomy)was performed. The postoperative course was uneventful.The definitive diagnosis was ganglioneuroma.Immunocytochemistry showed positive staining with vimentin,S-100 protein, neurofilament and neuron-specific enolase.Ganglioneuroma is a rare benign tumor that can also present as a pancreatic tumor.Uncinatectomy is feasible,safe and a good surgical technique for the treatment of nonmalignant tumors located in the uncinate process of the pancreas.

Clinicopathological analysis of paraganglioma with literature review

AIM： To investigate the 152 cases of paragangliomas resected over the past 32 years in West China Hospital dinicopathologically.METHODS： All cases of paragangliomas diagnosed at the Department of Gastrointestinal Surgery and Department of Pathology, West China Hospital, China were reviewed. The pathological documents were supplied by the Department of Pathology, West China Hospital, and other necessary data were extracted from the hospital records. The statistical analyses were performed by survival analysis （Kaplan-Meier method）, descriptive statistical analyses and Х^2 analysis.RESULTS： The neuroendocrine marker vimentin was found to be selectively expressed in the benign tumors, and there were significant differences in the expression of those markers in both benign and malignant tumors. The survival analysis revealed that survival correlated significantly with the malignancy, metastasis and nodal status.CONCLUSION： Vimentin may be useful in the differential diagnosis between malignant and benign tumors. The difference in the expression of this marker in the tumors could be a clue to the future clinical diagnosis. The malignancy, metastasis and the nodal status may predict the prognosis of this disease.