Differential diagnosis of primary benign and malignant retroperitoneal tumors

First total synthesis, antitumor evaluation and target identification of mornaphthoate E: A new tubulin inhibitor template acting on PI3K/Akt signaling pathway

Mornaphthoate E (MPE) is a prenylated naphthoic acid methyl ester isolated from the roots of a famous Chinese medicinal plant Morinda officinalis and shows remarkable cytotoxicity against several human tumor cell lines. In the current project, the first total synthesis of (±)-MPE was achieved in seven steps and 5.6% overall yield. Then the in vitro anti-tumor activity of MPE was first assessed for both enantiomers in two breast cancer cells, with the levoisomer exerting slightly better potency. The in vivo anti-tumor effect was further verified by applying the racemate in an orthotopic autograft mouse model. Notably, MPE exerted promising anti-metastasis activity both in vitro and in vivo and showed no obvious toxicity on mice at the therapeutic dosage. Mechanistic investigations demonstrated that MPE acted as a tubulin polymerization stabilizer and disturbed the dynamic equilibrium of microtubules via regulating PI3K/Akt signaling. In conclusion, our work has provided a new chemical template for the future design and development of next-generation tubulin-targeting chemotherapies.

Imaging in gynecological disease (26): clinical and ultrasound characteristics of benign retroperitoneal pelvic peripheral-nerve-sheath tumors

OBJECTIVE

To describe the clinical and sonographic characteristics of benign, retroperitoneal, pelvic peripheral-nerve-sheath tumors (PNSTs).

METHODS

This was a retrospective study of patients with a benign, retroperitoneal, pelvic PNST who had undergone preoperative ultrasound examination at a single gynecologic oncology center between 1 January 2018 and 31 August 2022. All ultrasound images, videoclips and final histological specimens of benign PNSTs were reviewed side-by-side in order to: describe the ultrasound appearance of the tumors, using the terminology of the International Ovarian Tumor Analysis (IOTA), Morphological Uterus Sonographic Assessment (MUSA) and Vulvar International Tumor Analysis (VITA) groups, following a predefined ultrasound assessment form; describe their origin in relation to nerves and pelvic anatomy; and assess the association between their ultrasound features and histotopography. A review of the literature reporting benign, retroperitoneal, pelvic PNSTs with preoperative ultrasound examination was performed.

RESULTS

Five women (mean age, 53 years) with a benign, retroperitoneal, pelvic PNST were identified, four with a schwannoma and one with a neurofibroma, of which all were sporadic and solitary. All patients had good-quality ultrasound images and videoclips and final biopsy of surgically excised tumors, except one patient managed conservatively who had only a core needle biopsy. In all cases, the findings were incidental. The five PNSTs ranged in maximum diameter from 31 to 50 mm. All five PNSTs were solid, moderately vascular tumors, with non-uniform echogenicity, well-circumscribed by hyperechogenic epineurium and with no acoustic shadowing. Most of the masses were round (n = 4 (80%)), and contained small, irregular, anechoic, cystic areas (n = 3 (60%)) and hyperechogenic foci (n = 5 (100%)). In the woman with a schwannoma in whom surgery was not performed, follow-up over a 3-year period showed minimal growth (1.5 mm/year) of the mass. We also summarize the findings of 47 cases of benign retroperitoneal schwannoma and neurofibroma identified in a literature search.

CONCLUSIONS

On ultrasound examination, no imaging characteristics differentiate reliably between benign schwannomas and neurofibromas. Moreover, benign PNSTs show some similar features to malignant retroperitoneal tumors. They are solid lesions with intralesional blood vessels and show degenerative changes such as cystic areas and hyperechogenic foci. Therefore, ultrasound-guided biopsy may play a pivotal role in their diagnosis. If confirmed to be benign PNSTs, these tumors can be managed conservatively, with ultrasound surveillance. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Preoperative contrast-enhanced CT-based radiomics nomogram for differentiating benign and malignant primary retroperitoneal tumors

OBJECTIVES

This study evaluated the ability of a preoperative contrast-enhanced CT (CECT)-based radiomics nomogram to differentiate benign and malignant primary retroperitoneal tumors (PRT).

METHODS

Images and data from 340 patients with pathologically confirmed PRT were randomly placed into training (n = 239) and validation sets (n = 101). Two radiologists independently analyzed all CT images and made measurements. Key characteristics were identified through least absolute shrinkage selection combined with four machine-learning classifiers (support vector machine, generalized linear model, random forest, and artificial neural network back propagation) to create a radiomics signature. Demographic data and CECT characteristics were analyzed to formulate a clinico-radiological model. Independent clinical variables were merged with the best-performing radiomics signature to develop a radiomics nomogram. The discrimination capacity and clinical value of three models were quantified by the area under the receiver operating characteristics (AUC), accuracy, and decision curve analysis.

RESULTS

The radiomics nomogram was able to consistently differentiate between benign and malignant PRT in the training and validation datasets, with AUCs of 0.923 and 0.907, respectively. Decision curve analysis manifested that the nomogram achieved higher clinical net benefits than did separate use of the radiomics signature and clinico-radiological model.

CONCLUSIONS

The preoperative nomogram is valuable for differentiating between benign and malignant PRT; it can also aid in treatment planning.

KEY POINTS

• A noninvasive and accurate preoperative determination of benign and malignant PRT is crucial to identifying suitable treatments and predicting disease prognosis. • Associating the radiomics signature with clinical factors facilitates differentiation of malignant from benign PRT with improved diagnostic efficacy (AUC) and accuracy from 0.772 to 0.907 and from 0.723 to 0.842, respectively, compared with the clinico-radiological model alone. • For some PRT with anatomically special locations and when biopsy is extremely difficult and risky, a radiomics nomogram may provide a promising preoperative alternative for distinguishing benignity and malignancy.

Imaging of Ganglioneuroma: A Literature Review and a Rare Case of Cystic Presentation in an Adolescent Girl

Retroperitoneal ganglioneuroma is a rare neuroectodermal tumor with a benign nature. We performed a literature review among 338 studies. We included 9 studies, whose patients underwent CT and/or MRI to characterize a retroperitoneal mass, which was confirmed to be a ganglioneuroma by histologic exam. The most common features of ganglioneuroma are considered to be a solid nature, oval/lobulated shape, and regular margins. The ganglioneuroma shows a progressive late enhancement on CT. On MRI it appears as a hypointense mass in T1W images and with a heterogeneous high-intensity in T2W. The MRI-"whorled sign" is described in the reviewed studies in about 80% of patients. The MRI characterization of a primitive retroperitoneal cystic mass should not exclude a cystic evolution from solid masses, and in the case of paravertebral location, the differential diagnosis algorithm should include the hypothesis of ganglioneuroma. In our case, the MRI features could have oriented towards a neurogenic nature, however, the predominantly cystic-fluid aspect and the considerable longitudinal non-invasive extension between retroperitoneal structures, misled us to a lymphatic malformation. In the literature, it is reported that the cystic presentation can be due to a degeneration of a well-known solid form while maintaining a benign character: the distinguishing malignity character is the revelation of immature cells on histological examination.

Large retroperitoneal leiomyoma developed from the pelvic floor to the buttocks

Retroperitoneal leiomyoma is a very rare disease, with little reported information on its origin. Herein, we report a case of a large retroperitoneal leiomyoma that developed from the pelvic floor. A 44-year-old woman had a large mass protruding outside the body from the right hip. Imaging revealed a large tumor developing from the pelvic floor to the buttocks. It was difficult to identify the place of origin. Upon preoperative biopsy, the patient was diagnosed with retroperitoneal leiomyoma. Tumor removal with abdominoperineal and partial vaginal resection was performed. Based on the histological findings of the surgical specimens, she was diagnosed with a retroperitoneal leiomyoma (gynecologic type) via immunohistochemistry, the tumor cells were positive for αSMA, desmin, estrogen receptor(ER), and progesterone receptor(PgR), but negative for myoglobin, S-100, CD34, and MIB-1.This is a case of a large retroperitoneal leiomyoma that was successfully removed via abdominoperineal and partial vaginal resection.

Inferior vena cava-syndrome

Inferior vena cava syndrome (IVCS) is caused by agenesis, compression, invasion, or thrombosis of the IVC, or may be associated with Budd-Chiari syndrome. Its incidence and prevalence are unknown. Benign IVCS is separated from malignant IVCS. Both cover a wide clinical spectrum reaching from asymptomatic to highly symptomatic cases correlated to the underlying cause, the acuity, the extent of the venous obstruction, and the recruitment and development of venous collateral circuits. Imaging is necessary to determine the underlying cause of IVCS and to guide clinical decisions. Interventional therapy has changed the therapeutic approach in symptomatic patients. This article provides an overview over IVCS and focuses on interventional therapeutic methods and results.

Non-functioning retroperitoneal abdominal schwannoma

There are less than 150 cases of non-functioning retroperitoneal abdominal schwannoma (NRS) reported. Hormonal assay is crucial in confirming the diagnosis of NRS, as manipulation of a functional retroperitoneal paraganglioma will instigate an abrupt liberation of catecholamines, resulting in devastating consequences. We report the case of 42-year-old woman who presented with headache, night sweats and abdominal discomfort. Cross-sectional imaging demonstrated a retroperitoneal mass adherent to the aorta and inferior vena cava but biochemical testing of blood and urine was negative for metanephrines and normetanephrines. She underwent successful tumour resection via laparotomy, as location increased the complexity and risk of laparoscopic resection.

Laparoscopic distal gastrectomy for gastric cancer with simultaneous resection of para-aortic schwannoma

An asymptomatic 74-year-old man was diagnosed with early gastric cancer during screening. Preoperative CT revealed a 25-mm tumor surrounded by the abdominal aorta, inferior vena cava, and left renal vein. Based on the primary tumor stage, para-aortic lymph node metastasis was considered to be unlikely but could not be ruled out. For this reason, we planned a concurrent diagnostic and therapeutic laparoscopic resection with gastrectomy. The gastric cancer and para-aortic tumor were successfully resected laparoscopically. The tumor was diagnosed as a schwannoma. With care and skill, we were able to resect the para-aortic schwannoma and gastric cancer simultaneously and safely by using laparoscopic techniques.

Evaluation of clinical application of multi-slice computerized tomography in primary retroperitoneal tumors

BACKGROUND

To accurately identify primary retroperitoneal tumors by multi-slice spiral CT (MSCT) for better treatment.

MATERIALS AND METHODS

The common types of 380 cases of primary retroperitoneal tumor, lesion sites, and MSCT features were compared with pathological results. Fisher's or chi-square test approaches have been applied in this study.

RESULTS

Multi-slice computerized tomography multi-directional reconstruction has a high accuracy for primary retroperitoneal tumors (95.7%). Seventy-three liposarcoma cases were located in peri-renal space, accounting for 76.8% (13/95) of the tumors in this region. Meanwhile, 65 cases of neurogenic tumors were located in the paravertebral column, accounting for 90.3% (65/72) of the tumors in this region. MSCT examination could effectively distinguish benign from malignant of primary retroperitoneal tumor (sensitivity = 87.2%, specificity = 82.7%, accuracy rate = 84.5%). Malignant tumors showed more irregularity shape than benign tumor (χ²  = 20.468, P < .001). 82.7% (191/231) of the malignant tumors showed adhesion or even invasion of surrounding tissues and organs (χ²  = 23.262, P < .001). Fat density of the lipoma is uniform, and lesion is not enhanced. Liposarcoma can be seen in varying proportions of fat and soft tissue density.

CONCLUSION

The accuracy of MSCT scan for retroperitoneal tumors is high. Meanwhile, the coincidence rate of qualitative diagnosis before operation and/or before biopsy is also high.

Anti-tubulin agents of natural origin: Targeting taxol, vinca, and colchicine binding domains

Microtubules are a protein which is made of α- and β-heterodimer. It is one of the main components of the cell which play a vital role in cell division especially in G2/M-phase. It exists in equilibrium dynamic of polymerization and depolymerization of α- and β-heterodimer. It is one of the best targets for developing anti-cancer drugs. Various natural occurring molecules are well known for their anti-tubulin effect such as vinca, paclitaxel, combretastatin, colchicine etc. These microtubule-targeted drugs are acted through two processes (i) inhibiting depolymerization of tubulin (tubulin stabilizing agents) and (ii) inhibiting polymerization of tubulin (tubulin destabilizing agents). Now days, various binding domains have been explore through which these molecules are binding to tubulin but the three major binding domain of tubulin are taxol, vinca and colchicine binding domain. The present article mainly focus on the classification of various naturally occurring compounds on the basis of their inhibition processes (depolymerization and polymerization) and the site of interaction (targets taxol, vinca and colchicine binding domain) which has been hitherto reported. By placing all the naturally occurring taxol, vinca and colchicine binding site analogues at one place makes a better understanding of the tubulin interactions with known natural tubulin binders that would helps in the discovery of new and potent natural, semi-synthetic and synthetic analogues for treating cancer.

MR imaging features of benign retroperitoneal paragangliomas and schwannomas

Background

To determine whether MRI feature analysis can differentiate benign retroperitoneal extra-adrenal paragangliomas and schwannomas.

Methods

The MRI features of 50 patients with confirmed benign retroperitoneal extra-adrenal paragangliomas and schwannomas were retrospectively reviewed by two radiologists blinded to the histopathologic diagnosis. These features were compared between two types of tumours by use of the Mann-Whitney test and binary logistic regression. The patients’ clinical characteristics were reviewed.

Results

Analysis of MRI images from 50 patients revealed no significant differences in the quantitative MRI features of lesion size, ratio of diameter and apparent diffusion coefficient. There were significant differences in the qualitative MRI features of location, necrosis, cysts and degree of tumour enhancement for two readers, with no significant differences in the other qualitative MRI features between these tumours. The combination of necrosis with degree of tumour enhancement during the arterial phase increased the probability that a retroperitoneal mass would represent retroperitoneal extra-adrenal paraganglioma as opposed to schwannoma.

Conclusion

We have presented the largest series of MRI features of both benign retroperitoneal extra-adrenal paragangliomas and schwannomas. Some MRI features assist in the differentiation between these tumours, with imaging features consisting of necrosis and avid enhancement during the arterial phase, suggestive of retroperitoneal extra-adrenal paragangliomas.

MR imaging features of benign retroperitoneal extra-adrenal paragangliomas

The goal of this study was to retrospectively review the magnetic resonance imaging (MRI) features of retroperitoneal extra-adrenal paragangliomas and to evaluate the diagnostic capabilities of MRI. Twenty-four patients with confirmed benign retroperitoneal extra-adrenal paragangliomas who underwent preoperative MRI and surgical resection were enrolled. The patients’ clinical characteristics and MRI features were reviewed by two radiologists. There were no significant differences in the qualitative and quantitative MRI features were determined by the reviewers. High signal intensity in T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) was observed in all tumors. In contrast T1-weighted imaging (T1WI) in the arterial phase, 83.33% of the tumors were clearly enhanced. In 87.5% of cases, a persistent enhancement pattern was observed in the venous and delayed phases, and 12.5% of tumors showed a “washout” pattern. The tumor capsule, intratumoral septum and degenerations were visualized in the tumors and may be helpful in the qualitative diagnosis of extra-adrenal paragangliomas in MRI. MRI was useful in locating the position, determining the tumor ranges and visualizing the relationship between the tumors and adjacent structures. The presence of typical clinical symptoms and positivity of biochemical tests are also important factors in making an accurate preoperative diagnosis.

Primary retroperitoneal mature cystic teratoma (dermoid cyst) in a 51-year-old male:Case report and historical literature review

OBJECTIVES

Primary retroperitoneal mature cystic teratomas are exceedingly uncommon in males aged 50 years and above, and only seven cases have been reported in the literature so far. They usually occur in infants less than 6 months and young females. The aim of this article is to present a rare case of a 51-year-old male with a primary retroperitoneal mature cystic teratoma located in the right infrarenal area adherent to the psoas muscle and to discuss a historical literature review.

METHODS

An incidental hypoechoic, solid appearing 8.2 × 7.6 × 7.8 cm3 mass arising off the inferior pole of the right kidney was found on abdominal ultrasound during evaluation for a history of alcoholism. Computerized tomography (CT) scan revealed small calcifications in the lower part of the cystic mass. Laparotomy with excision of the retroperitoneal mass was performed.

RESULTS

On gross examination, the specimen consisted of a cyst filled with pale yellow greasy material with entrapped hair. Histopathologic examination revealed a dermoid cyst with focal chronic inflammation, dystrophic calcification, and foreign-body giant cell reaction.

CONCLUSIONS

Retroperitoneal mature cystic teratoma in an older male is extremely rare. Primary gonadal teratoma with retroperitoneal metastasis should be excluded first. Evaluation of age and location of tumor are critical for its prognosis. Complete excision of tumor is necessary to evaluate whether there are immature and solid elements which need long-term follow up due to the increased risk of malignancy.

Characteristics and computed tomography evaluation of primary retroperitoneal tumours: report of 113 cases

INTRODUCTION Benign and malignant primary retroperitoneal tumours (PRT) have different clinical manifestations and pathological characteristics. We explore the characteristics and evaluate the value of computed tomography (CT) for PRT. METHODS Fifty-six benign and fifty-seven malignant PRT with clinical, radiographic and surgical data were retrospectively investigated. Statistical analysis was carried out using SPSS software. RESULTS We found that mean size of benign tumours was 12.4 ± 7.7cm but 20.7 ± 11.6cm in malignant cases (P < 0.05). The accuracy of CT localisation was approximately 70%. The sensitivity and specificity of CT diagnosis for benign tumours were 96% and 85%, respectively; 51 (91%) underwent complete resection among benign cases but 42 (74%) in malignant cases (P < 0.05). Sensitivity of CT evaluation for invaded organs and vessels was 50% and 65%, respectively, and specificity was 88% and 81%, respectively. CONCLUSIONS Large size, no capsule, irregular margin, heterogeneous density and specific enhancement pattern on CT are highly suggestive of malignancy. CT is the most useful tool in assessing the size and characteristics of PRT but it does not have the sensitivity to assess the involvement of organs and vessels.

Integrally calcified solitary fibrous tumor in the retroperitoneum: a case report and review of the literature

Solitary fibrous tumor (SFT) is a rare stromal neoplasm and usually occurs in the thoracic cavity. We here report a case of retroperitoneal SFT with prominent calcification. A 64-year-old man presented with an incidentally detected retroperitoneal mass in the right upper abdomen. Imaging tests indicated an integrally calcified mass. The lesion was observed for 2 years and laparoscopically resected according to the patient's wish. Microscopically, the mass was mostly occupied by calcification and proliferous spindle cells were scattered with positive CD34 expression. We diagnosed morphologically benign SFT and the patient remained disease-free 1 year after the excision. There has been no report of such integrally calcified SFT. Retroperitoneal SFT is difficult to make a preoperative diagnosis, and careful follow-up after the excision is recommended because morphological malignancy does not always correspond to clinical malignancy.

Surgical treatment of a retroperitoneal benign tumor surrounding important blood vessels by fractionated resection: A case report and review of the literature

Retroperitoneal tumors are lesions with diverse pathological subtypes that originate from the retroperitoneal space; ~40% of these tumors are benign. Due to such lesions often surrounding and associating with vital abdominal blood vessels, a complete surgical resection is difficult. The current study presents a novel surgical approach, known as fractionation, through which a benign retroperitoneal tumor surrounding important abdominal blood vessels was completely resected. A 21-year-old man was admitted to The First Affiliated Hospital of Chongqing Medical University (Chongqing, China), presenting with a ~7.5×7.2-cm tumor that was located in the retroperitoneal pancreatic head region and the first hepatic hilum. The tumor completely surrounded the celiac axis and the splenic, common hepatic and superior mesenteric arteries, and was closely associated with the abdominal aorta and the portal, splenic, superior mesenteric and left renal veins. A pre-operative computed tomography scan and intraoperative frozen biopsy indicated that the lesion was a benign tumor. A fractionation approach was subsequently adopted, with fractionation of the lesion being performed according to the location of the tumor itself and the direction of the surrounding abdominal blood vessels. In this manner, a complete tumor resection was conducted. Post-operative pathological examination confirmed the diagnosis of a retroperitoneal ganglioneuroma. The patient was followed up for a year and a half, with no evidence of tumor recurrence. In the present case, a fractionation approach for the complete resection of the retroperitoneal benign tumor achieved a positive outcome and demonstrated the feasibility of the technique.

Giant abdominoperineal malignant schwannoma: an unusual presentation and surgical challenge

Schwannoma is a benign tumor arising from the Schwann cells of peripheral nerves. These are usually benign but malignant transformation can occur in larger lesions. The definitive diagnosis of malignancy can only be made after final histopathological report. The literature reports large pelvic and perineal schwannomas with few being malignant. We report the first case of such giant malignant abdominoperineal schwannoma which was benign on initial biopsy but final histopathology revealed it to be malignant. In view of proximity of perineal and pelvic tumors to urogenital organs and pelvic nerves, such cases represent a challenge to surgical excision. This case brings to highlight another atypical presentation of such tumors.

Laparoscopic resection of a retroperitoneal schwannoma located in the hepatic hilus

Schwannomas are tumors and commonly occur in the head and neck region; however, they rarely present in the retroperitoneum. A 79-year-old man was admitted to our hospital for a follow-up of a tumor in the hepatic hilus. A 2.8 × 2.5 cm solid tumor located between the hepatic hilus and common hepatic artery was originally identified, and the size of the tumor had increased from 2.0 × 2.0 cm to 2.8 × 2.5 cm over the course of 3 years. The patient underwent percutaneous sonopsy, and the tumor was subsequently diagnosed as a benign schwannoma. Since the patient wished to undergo an operation, we performed laparoscopic surgery. During the operation, the tumor was detected in the retroperitoneal space, where it was strongly adhered between the left gastric artery and common hepatic artery. At this point, no major vessels had vascularized the tumor. We then completely removed the tumor from the retroperitoneal space without any complications. The clinical course was uneventful, and the patient was discharged on postoperative day 4 without any symptoms. Later, a definitive histopathologic examination revealed a benign schwannoma. Here, we report this rare case of a retroperitoneal schwannoma located in the hepatic hilus.

Pudendal schwannoma: A case report and literature review

Schwannomas are benign nerve sheath tumours most often associated with the cranial nerves and the peripheral nerve system of the neck and extremities. Pelvic schwannomas are rare, with only about 25 cases reported. We report the case of a 34-year-old man referred for worsening pain of 10 years duration involving the right testicle and right penile shaft. Magnetic resonance imaging discovered a well-circumscribed pelvic tumour of 3.2 × 2.8 × 3.2 cm. Considering the possible complications involved in exposing the pudendal nerve during surgical resection, we performed an extensive literature search to aid preoperative planning. The most commonly described surgical approach for pelvic schwannomas has been open median laparotomy with transperitoneal dissection. To our knowledge, pudendal schwannomas have never been described in the literature. However, after considering the location and characteristics of the tumour, we chose laparoscopy because it offers the advantages of better visualization of anatomical structures with minimal invasiveness and faster recovery. At the 3-week follow-up, the patient described a significant decrease in pain and normal neurological and urological examinations.

Successful treatment for retroperitoneal cavernous hemangioma adjacent to the renal hilum via the laparoscopic approach: a case report

Introduction

Cavernous hemangiomas are common benign tumors of the skin or liver but can also rarely originate from the retroperitoneal space, especially adjacent to the renal hilum. Qualitative characterization of these retroperitoneal tumors using available imaging modalities is relatively difficult.

Case presentation

A 40-year-old Japanese woman was incidentally noted to have a round homogenous tumor adjacent to the left renal hilum on computed tomography. The preoperative diagnosis was paraganglioma according to hormonal and clinical findings. The tumor was successfully resected via a laparoscopic approach, and histopathological examination of the tumor revealed cavernous hemangioma.

Conclusions

Cavernous hemangioma is a rare but relatively benign disease when considering the different types of retroperitoneal tumors. We were able to effectively treat the retroperitoneal cavernous hemangioma via laparoscopy.

Retroperitoneal schwannomas in the anterior pararenal space: dynamic enhanced multi-slice CT and MR findings

BACKGROUND

To evaluate the imaging features of schwannomas in the anterior pararenal space (APS), especially focusing on dynamic enhanced multi-slice CT (MSCT) and MR findings.

PATIENTS AND METHODS

Eight patients with pathologically proved retroperitoneal schwannomas in the APS underwent dynamic enhanced multi-slice CT (MSCT), while three of these patients also had a contrast-enhanced MR examination. The imaging findings were retrospectively reviewed.

RESULTS

All eight cases exhibited forward displacement of the pancreas, and three cases showed lateral displacement and compression of the inferior vena cava. The tumors had round or oval shape with a maximal axial diameter of 4.0-12.3 cm (average, 6.7 cm). All eight tumors were solitary and well circumscribed. Of the eight retroperitoneal schwannomas in the APS, six exhibited a capsule with thickness of 1.0-2.0 mm, one showed punctate calcification, two displayed cystic degeneration, and three revealed a "target sign" on CT and MR. The tumors were hypo-dense on unenhanced CT images, hyper-intense on T2W images, and homogeneously hypo-intense on T1W images. All eight tumors exhibited gradual enhancement on dynamic enhanced CT or MR images. One case showed delayed enhancement. Heterogeneous enhancement was the dominant pattern occurring in seven out of eight tumors.

CONCLUSION

The imaging findings of schwannoma in the APS correspond with its pathological composition. Schwannoma should be included in the differential diagnosis of tumors in the APS.

Giant presacral schwannoma presenting with constipation: a case report

Introduction

Schwannoma, otherwise known as a neurilemmoma, is a tumor arising from peripheral nerve sheaths. Although commonly noted in association with the eighth cranial nerve as intracranial acoustic neuroma, cases of schwannoma arising in other locations have been reported in the literature. These tumors usually cause symptoms as a result of their mass effect and, since they are benign, encapsulated and non-invasive tumors, complete surgical excision is considered curative.

Case presentation

We report the case of a 46-year-old Sri Lankan man who presented to our facility with recent onset of difficulty evacuating his bowels. He was noted to have a giant presacral schwannoma on magnetic resonance imaging scan. The mass was surgically excised with improvement of our patient’s symptoms. A subsequent histopathological examination confirmed the presence of a benign schwannoma.

Conclusions

Although schwannomas commonly occur in the extremities, a rare case of occurrence in the pelvis is reported here. Due to the limited space in the pelvis, the local mass effect may be the presenting feature of such a lesion and surgical excision is curative.

A bronchogenic cyst, presenting as a retroperitoneal cystic mass

Bronchogenic cysts are mostly benign, congenital abnormalities originating from the remnants of the primitive foregut. A retroperitoneal location is rare. Due to the mostly asymptomatic behavior and the historical confusion regarding histology, an exact prevalence is not known. We present here a case report of a retroperitoneal bronchogenic cyst. A literature review was performed for cases of retroperitoneal bronchogenic cysts written in English. Anatomopathological criteria for inclusion were pseudo stratified, ciliated, columnar epithelium together with the presence of at least one of the following: cartilage, smooth muscle or seromucous glands. In addition, the embryology, pathogenesis, radiological, clinical and suggested treatment modalities are reviewed. We report the surgical excision of a retroperitoneal bronchogenic cyst that presented as a non-functioning left adrenal mass. Our review of literature revealed only 62 potential cases of retroperitoneal bronchogenic cysts. After applying the strict anatomopathological criteria, only 30 cases of true retroperitoneal bronchogenic cysts could be identified. Retroperitoneal location of a bronchogenic cyst is rare. Despite the rarity of this pathologic entity, bronchogenic cysts should be considered in the differential diagnosis of retroperitoneal cystic lesions. Only histology can confirm definitive diagnosis. Surgery remains the recommended treatment of choice.

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.

Recent progress in the management of retroperitoneal sarcoma

Retroperitoneal sarcomas (RPS) are rare tumours that typically present late and carry a poor prognosis even following grossly complete resection. In an attempt to improve the outlook for patients with RPS, sarcoma specialists have employed various adjuvant therapies, including extermal beam radiation, intraoperative radiation, brachyradiation and systemic chemotherapy. This article reviews the presentation and prognosis of RPS, and focuses on the results of new treatment strategies compared with conventional management.

A Medline search of the English literature was performed to identify all retrospective and prospective reports relating to the management of adult RPS published since 1980. Series that did not analyse RPS separately from other intra-abdominal or extra-abdominal sarcomas or other malignancies were excluded, and information on investigation, presentation, prognostic factors, treatment and outcome was extracted from the remaining reports. Survival and local control data were collected from reports that contained at least 30 cases of RPS (n = 31).

While surgical resection remains the cornerstone of treatment for RPS, the majority of patients will relapse and die from sarcoma within 5 years of resection. Adjuvant radiation may improve these results, but further trials are required to definitively demonstrate its benefit. Possible reasons for the failure of conventional treatment are discussed, and alternative strategies designed to overcome these obstacles are presented.

Low-back pain as the presenting sign in a patient with a giant, sacral cellular schwannoma: 10-year follow-up

Giant sacral tumors present unique challenges to surgeons because there is no established consensus regarding the best treatment options. The authors report on the care of and outcome in a patient presenting with low-back pain only, who underwent preoperative biopsy sampling and subsequent embolization of the feeding vessels of a giant, sacral cellular schwannoma. The main procedure was performed via a combined posterior-anterior approach with complete microsurgical removal of the tumor, without the use of instrumentation, bracing, or adjuvant radio- and chemotherapy. At the 10-year follow-up, no evidence of residual tumor, recurrence, or instability was recognizable. Giant, sacral cellular schwannomas can be aggressively completely removed without any significant morbidity, achieving long-term control of the disease.

Intramuscular schwannoma arising from the psoas muscle presenting with femoral nerve neuropathy

A spherical mass of the right psoas muscle was found incidentally by magnetic resonance health examination in a 43-year-old woman. The patient had complained of numbness in her right leg over the previous six months and neuralgia at the time of computed tomography-guided core biopsy, which was done to establish the diagnosis. To our knowledge, femoral nerve neuropathy caused by an intramuscular schwannoma arising from the psoas muscle has not been previously published.

Laparoscopic excision of retroperitoneal tumors: report of three cases

Retroperitoneal neural tumors are rarely excised laparoscopically, with fewer than ten cases reported in the literature. Between February 2005 and December 2007, we performed successful planned laparoscopic excision of retroperitoneal tumors using the four-trocar technique in three patients. All three patients were women, with a mean age of 40.7 years. The mean tumor size was 4.8 cm. The mean operative time was 126 min and the mean blood loss 14.3 ml. The postoperative pathological diagnosis was schwannoma in one patient and ganglioneuromas in two. There was no morbidity or mortality. Although difficult to diagnose preoperatively, neural tumors in the retroperitoneal space are most often benign, with a good prognosis. Laparoscopic surgical techniques for retroperitoneal tumors are safe, and their use is encouraged when an appropriate diagnosis is made, after exclusion of malignant subtypes.

A unique benign mucinous cystadenoma of the retroperitoneum: a case report and review of the literature

Primary retroperitoneal mucinous cysts are rare. Most often malignant, lesions present on a spectrum, fitting the histopathological categories of benign, borderline and malignant. The rarest form is the benign mucinous cystadenoma adenocarcinoma, of which only 20 cases have been reported. We present here the curious case of a 37-year-old woman with two large, fast growing, cystic, benign, primary retroperitoneal mucinous cystadenomas treated definitively by local resection.

Alpha-fetoprotein levels correlate with the pathologic grade and surgical outcomes of pediatric retroperitoneal teratomas

INTRODUCTION

Retroperitoneal teratomas (RTs) are rare neoplasms that comprise 2-5% of all pediatric teratomas and 10% of all pediatric retroperitoneal tumors. Although alpha-fetoprotein (AFP) is a recognized tumor marker for immature teratomas, its prognostic value in neonates and children with RTs is unknown due to physiologic elevation of this marker. The aim of this study was to determine whether AFP level correlates with pathologic grade of pediatric RT and patient outcome.

METHODS

A retrospective analysis of all RTs seen at our institution over a 20-year period was performed. Thirteen patients with RTs were identified; their AFP levels were correlated with tumor grade, patient age, and outcome.

RESULTS

Twelve patients were less than 1 year of age at diagnosis. There were nine patients with immature, and four with mature RTs. All patients with mature RTs had AFP levels within the normal range, while eight out of nine patients with immature RTs had elevated AFP levels. A statistically significant elevation in AFP was noted in grade III RTs compared with mature RTs (P = 0.036), regardless of age. Major complications including vascular injury, sepsis, and death were more prevalent in high-grade RTs.

CONCLUSION

We conclude that AFP levels correlate with tumor immaturity and predict operative morbidity even in patients less than 2 months of age. Despite the increased morbidity associated with surgical excision of high-grade RTs, complete resection results in long-term disease-free survival in the majority of infants with this rare pediatric neoplasm.

Clinicopathological review of 46 primary retroperitoneal tumors

OBJECTIVES

To clarify the clinical factors including diagnostic imaging findings that may correlate with the histopathological malignancy in primary retroperitoneal tumors.

METHODS

The clinical backgrounds and imaging findings of 22 benign and 24 malignant primary retroperitoneal tumors were retrospectively investigated, and the prognosis of patients with malignant retroperitoneal tumors was assessed.

RESULTS

There were significant correlations between the presence of symptoms and malignancy (P < 0.01), as well as between the irregularity of tumor margins and malignancy (P < 0.01). On dynamic magnetic resonance imaging (MRI), 90% of malignant tumors showed early enhancement either with quick or slow washout, while 75% of benign tumors showed delayed and no enhancement (P < 0.002). All malignant and benign paraganglioma showed the same early enhancement with quick washout. Malignant lymphoma showed various enhancement patterns. The 2-year and 5-year cause-specific survival rates of the patients with malignant retroperitoneal tumors were 68.0% and 43.2%, respectively. All malignant lymphoma patients were mainly treated with chemotherapy after being diagnosed histologically. Malignant paraganglioma patients who could not meet complete resection needed chemotherapy for promising survival.

CONCLUSION

The symptoms, the irregularity of the margins, and the specific enhancement pattern on the dynamic MRI may be important predictive factors of the primary malignant retroperitoneal tumors. Histological diagnosis was needed for malignant definition of paraganglioma because both benign and malignant paraganglioma showed similar clinical and imaging findings. Preoperative biopsy should be considered for selection of the appropriate treatment particularly in patients that are likely to have malignant lymphoma that could not be diagnosed definitively by the clinical and imaging findings.

Benign retroperitoneal schwannoma presenting as colitis: A case report

We report a case of a patient presenting with clinical, radiological and endoscopic features of colitis due to a compressive left para-aortic mass. Total open surgical excision was performed, which resulted in complete resolution of colitis. Histopathology and immunohistochemistry revealed benign retroperitoneal schwannoma. These neural sheath tumors rarely occur in the retroperitoneum. They are usually asymptomatic but as they enlarge they may compress adjacent structures, which leads to a wide spectrum of non-specific symptoms, including lumbar pain, headache, secondary hypertension, abdominal pain and renal colicky pain. CT and MR findings show characteristic features, but none are specific. Schwannoma can be isolated sporadic lesions, or associated with schwannomatosis or neurofibromatosis type II (NF2). Although they vary in biological and clinical behavior, their presence is, in nearly every case, due to alterations or absence of the NF2 gene, which is involved in the growth regulation of Schwann cells. Both conditions were excluded by thorough mutation analysis. Diagnosis is based on histopathological examination and immunohistochemistry. Total excision is therapeutic and has a good prognosis. Schwannomatosis and NF2 should be excluded through clinical diagnostic criteria. Genetic testing of NF2 is probably not justified in the presence of a solitary retroperitoneal schwannoma.

Analysis of 82 cases of retroperitoneal schwannoma

BACKGROUND

The aim of the study was to improve the diagnosis and treatment of retroperitoneal schwannoma by analysing clinical manifestations and postoperative course of this rare disease.

METHODS

A retrospective analysis of 82 patients with retroperitoneal schwannoma between January 1951 and September 2004 was carried out.

RESULTS

The patients were 38 (46%) men and 44 (54%) women between the ages of 6 months and 70 years. The interval between clinical manifestation and diagnosis ranged from 10 days to 2 years. The main symptoms were abdominal distension (30.5%) and abdominal pain (20.7%). Only in 13 patients (15.9%) a correct preoperative diagnosis was made by either ultrasound-guided biopsy, computed tomography scanning or magnetic resonance imaging. All patients received operative therapy. Sixty patients (73.2%) underwent a total resection; 13 patients (15.9%) subtotal resection, but 9 patients (11.0%) had only an examination and a biopsy. Two patients (2.4%) had multiple schwannomas and two others had a simultaneous malignancy (adenocarcinoma of the ascending colon and squamous-cell carcinoma of the lung, respectively). Most of the retroperitoneal schwannomas were close to the spine. Pathological results showed 81 (98.8%) were benign schwannoma and 1 (1.2%) was a malignant one. The tumour size ranged from 3 to 22 cm. One benign schwannoma recurred 3 years after the operation. The patient with malignant schwannoma died 18 months after the operation because of metastasized disease.

CONCLUSION

Most of the retroperitoneal schwannomas are benign. It is difficult to make an accurate preoperative diagnosis. However, with the preoperative assessment of ultrasound-guided fine-needle aspiration, computed tomography and magnetic resonance imaging, the accuracy of diagnosis could definitely be improved. Treatment depends solely on surgery. Malignant schwannomas are insensitive to chemotherapy and radiation, resulting in poor prognosis.

A Rare Case of Precoccygeal Endometriosis

BACKGROUND

Endometriosis is commonly identified in the abdomen, specifically the ovaries, adnexa, and fallopian tubes, and sometimes in more distant areas; precoccygeal endometriosis is an extremely rare phenomenon.

CASE

We present a case involving a 44-year-old woman diagnosed and treated for precoccygeal endometriosis. She underwent laparotomy, extensive lysis of pelvic adhesions, and resection of a 2.5-cm midline precoccygeal mass. After surgical excision of the precoccygeal endometriosis, the patient recovered without incident.

CONCLUSION

Precoccygeal endometriosis is a very rare diagnosis.

Imaging features of retroperitoneal and pelvic schwannomas

AIM

To describe the imaging features of retroperitoneal and pelvic schwannomas.

MATERIALS AND METHODS

The presenting cross-sectional imaging for 18 sequential patients with retroperitoneal or pelvic schwannomas was reviewed retrospectively. Note was made of tumour diameter, position, homogeneity, margin, shape, calcification and invasion into adjacent structures. Where MRI had been performed, T1 and T2 signal intensity relative to skeletal muscle, and the degree and pattern of enhancement with gadolinium, were also assessed.

RESULTS

Imaging from 13 patients was available for review. The mean tumour diameter was 8.7 cm (range 4 to 15 cm); 9 schwannomas were located in the pelvis and 4 in the retroperitoneum; 12 cases showed smooth, regular margins and 1 case irregular, invasive margins. The tumours were homogeneous in 5 cases and heterogeneous with cystic change in 8; in 2 cases there was smooth expansion of a sacral nerve root exit foramen, and in 1 there was bony destruction of the sacrum and extension of tumour into the spinal canal. In 5 cases MRI was performed; on T1-weighted images all tumours were isointense; on T2-weighted images 4 tumours were hyperintense and 1 was isointense to skeletal muscle. In all cases the diagnosis was confirmed by core biopsy.

CONCLUSION

Retroperitoneal and pelvic schwannomas typically form large, well-circumscribed masses in the retroperitoneum or presacral area, and frequently undergo cystic degeneration. They can occasionally cause bony changes in the spine, but otherwise do not invade or obstruct adjacent structures. Although they are rare, it is important for the radiologist to recognize the typical appearance of schwannomas because they can be mistaken for malignant tumours.

Appearance and distinguishing features of retroperitoneal calcifications at computed tomography

OBJECTIVES

To describe the appearance of retroperitoneal calcifications seen at computed tomography (CT) and to investigate which CT features distinguish benign from malignant retroperitoneal calcifications.

METHODS

We identified 25 patients with retroperitoneal calcifications by retrospective review of 39,931 abdominopelvic CT scans. Etiology of retroperitoneal calcifications was determined by examination of medical and histopathological records. By consensus, 2 abdominal radiologists recorded calcification number (solitary or multiple), location (suprarenal or infrarenal), morphology (globular or nonglobular), and the presence of soft-tissue components. The association between CT findings and etiology was assessed using the Fisher exact test.

RESULTS

Retroperitoneal calcifications were malignant in 15 patients and benign in 10. Solitary calcifications were seen more commonly in patients with benign disease (6 of 10 vs. 1 of 15, P < 0.01). Suprarenal calcifications were seen only in patients with malignancy (13 of 15 patients, P < 0.01). Nonglobular calcifications were seen only in patients with benign disease (6 of 10, P < 0.01). Soft-tissue components were seen more commonly in patients with malignancy (14 of 15 vs. 4 of 10; P < 0.01).

CONCLUSIONS

Retroperitoneal calcifications are rarely seen at CT and may be benign or malignant in etiology. Solitary or nonglobular retroperitoneal calcifications are likely to be benign while calcifications that are multiple, globular, suprarenal, or associated with noncalcified soft-tissue components are likely to be malignant.

Retroperitoneal benign schwannoma: report of three cases and analysis of clinico-radiologic findings

Retroperitoneal schwannoma is a rare tumor that originates in the neural sheath and accounts for only a small percentage of retroperitoneal tumors. Presentation is typically varied and non-specific ranging from abdominal pain, abdominal mass or an incidental finding and the diagnosis is quite often fortuitous being confirmed by anatomopathological study afterwards. We report 3 cases of benign retroperitoneal pelvic schwannoma with varied presentations. Main symptoms were abdominal and pelvic pain whereas a patient with left parailiac mass had urinary incontinence and left lower extremity pain. Surgical exploration and complete excision of tumors were successful. The histological diagnosis of the tumors was reported as benign schwannoma. All patients are doing well and had no symptoms of motor or sensory disturbances after surgery with a mean follow up of 18 mounts.

Benign retroperitoneal schwannoma mimicking an adrenal mass

Adrenal tumors are frequently incidental discoveries, and the therapy for them is the subject of controversial discussions. We report herein on such an incidentaloma, which proved to be a benign retroperitoneal schwannoma. A 48-year-old female with an unclear adrenal mass underwent retroperitoneoscopic tumor extirpation. A well-defined tumor that displaced the adrenal gland and adhered firmly to only one retroperitoneal nerve was discovered. The en bloc resection was performed without problem. The histopathologic examination revealed a benign schwannoma. Retroperitoneal schwannomas can mimic a multitude of different conditions. Because imaging methods frequently do not yield distinct results, quite often only the operative exploration can establish a definitive diagnosis. In a case of unclear retroperitoneal findings, an endoscopic extirpation should be considered.

Retroperitoneal ancient schwannoma: case report and analysis of clinico-radiological findings

Ancient schwannoma is a rare subtype of typical schwannoma, with histological predominance of degenerative findings. We report the second case of retroperitoneal ancient schwannoma (occurred in a 45-year-old female referred to our institution for an unremitting right lumbar pain) and pinpoint clinical, radiological, prognosis and therapeutic aspects of this tumor.

Primary retroperitoneal ganglioneuroblastoma in an adult

A case of retroperitoneal ganglioneuroblastoma in a 60-year-old man is reported. This retroperitoneal tumor was surgically removed and pathologic diagnosis was ganglioneuroblastoma. Ganglioneuroblastoma usually occurs in children and is extremely rare in adults. The characteristics are described of an unusual tumor based on the published reports.