Multiple tumors and a novel E2F-4 mutation. A case report

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.

Systematic study on expression and prognosis of E2Fs in human colorectal cancer

BACKGROUND

E2Fs are important components of transcription factors and play key roles in occurrence or advancement of various cancers, but the expression and exact roles of each E2F in colorectal cancer (CRC) are rarely known.

METHODS

To address this issue, we investigated the roles and prognostic values of E2Fs expressions in CRC patients by searching ONCOMINE, cBioPortal, GEPIA, Matascape and UALCAN.

RESULTS

E2F1, 3-8 were upregulated at the mRNA level and E2F2 was less expressed in CRC tissues than in normal tissues. The eight E2Fs were correlated with tumor stages of CRC. Survival analysis using GEPIA revealed that high expressions of E2F3, 4 were related with short overall survival in all CRC patients. The mutation rate of E2Fs (60%) was high and genetic alteration in E2Fs was linked with longer overall survival in CRC patients. Functional analysis implied that E2Fs and their 50 nearby genes were concentrated in tumor-related pathways.

CONCLUSIONS

E2Fs may be candidate biomarkers for CRC diagnosis and E2F3, 4 are potential prognosis biomarkers of CRC. Nevertheless, our findings must be validated in the future to popularize the clinical application of E2Fs in CRC.

[Giant lipomas or retroperitoneal liposarcomas? Controversies in their diagnosis and treatment]

BACKGROUND

Retroperitoneal lipomas are extremely rare tumors that must be differentiated from well-differentiated liposarcomas (WD-LPS).

OBJECTIVES

To summarize the evidence about giant retroperitoneal lipomas or liposarcomas; and to elaborate recommendations for their management.

DATA SOURCES

A systematic literature search from January 1985 to December 2019 and a review of our own cases was performed.

RESULTS

Our series comprises four patients, two females and two males. The diagnosis was incidental in two cases. The medium size was 26 cm, being two cases located exclusively in the retroperitoneum, one in the inguinal region and one in the buttock via pelvic space. All cases were surgically removed being confirmed the initial diagnosis of retroperitoneal lipomas in two cases, as the rest two cases were classified as WD_LPS after MDM2/CDK4 genetic analysis. The review of the available literature plus our own cases revealed 30 cases, of which 58% were woman. Only two cases were asymptomatic. The main symptom was abdominal mass (53%) followed by abdominal pain (40,6%). The median size of the lesions was 24,9 cm with a median weight of 4.576,3 g. All cases were surgically removed, being necessary to remove contiguous organs in only four cases (12,5%).

CONCLUSIONS

Retroperitoneal lipoma is a rare tumor which must be differentiated from WD-LPS. This is a very difficult task, being necessary to determinate MDM2 status (by FISH or MLPA), present in liposarcoma but not in lipomas, for its correct diagnosis. The treatment must be based on a complete surgical resection with negative margins.

Retroperitoneal lipoma; a benign condition with frightening presentation

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Lipoma is the most frequent soft tissue tumor in adults.

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Its occurrence in the retroperitoneal region is extremely rare.

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It presents with various clinical scenarios.

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We present a case of retroperitoneal lipoma with a brief literature review.

Introduction

lipoma is the most frequent soft tissue tumor in adults. Its occurrence in the retroperitoneal region is extremely rare. The aim of this study is to report a case of retroperitoneal lipoma with a literature review.

Presentation of case

A 34-year-old female presented with abdominal distension and severe back pain for one year duration. She also reported weight loss and constipation. The examination revealed asymmetrical abdominal distension and everted umbilicus. There was a big irregular mass occupying the whole abdomen reaching into the xiphisternum, firm in consistency, smooth surface, and well defined borders. Abdominal ultrasound demonstrated a large retroperitoneal heterogeneous mass. Computed tomography (CT) scan showed a large well defined hyperechoic mass with fibrous septa extending from the left ovary up to the diaphragm. Exploratory laparotomy revealed a giant clearly demarcated fatty tumor adherent to the retroperitoneal fatty tissues. The histopathological examination of the specimen confirmed the diagnosis of the retroperitoneal lipoma.

Discussion

Retroperitoneal lipomas have been reported in various age groups; namely children, middle and old age patients. Based on the characteristic radiological features of the tumor, enormous diagnostic work-up is not justified.

Conclusion

Retroperitoneal lipoma is a very rare variant of lipoma, presents with various signs and symptoms that may be misleading. Radiologic imaging especially CT scan is the diagnostic tool of choice. Surgical resection is the main modality of management.

The Immunome of Colon Cancer: Functional In Silico Analysis of Antigenic Proteins Deduced from IgG Microarray Profiling

Characterization of the colon cancer immunome and its autoantibody signature from differentially-reactive antigens (DIRAGs) could provide insights into aberrant cellular mechanisms or enriched networks associated with diseases. The purpose of this study was to characterize the antibody profile of plasma samples from 32 colorectal cancer (CRC) patients and 32 controls using proteins isolated from 15,417 human cDNA expression clones on microarrays. 671 unique DIRAGs were identified and 632 were more highly reactive in CRC samples. Bioinformatics analyses reveal that compared to control samples, the immunoproteomic IgG profiling of CRC samples is mainly associated with cell death, survival, and proliferation pathways, especially proteins involved in EIF2 and mTOR signaling. Ribosomal proteins (e.g., RPL7, RPL22, and RPL27A) and CRC-related genes such as APC, AXIN1, E2F4, MSH2, PMS2, and TP53 were highly enriched. In addition, differential pathways were observed between the CRC and control samples. Furthermore, 103 DIRAGs were reported in the SEREX antigen database, demonstrating our ability to identify known and new reactive antigens. We also found an overlap of 7 antigens with 48 “CRC genes.” These data indicate that immunomics profiling on protein microarrays is able to reveal the complexity of immune responses in cancerous diseases and faithfully reflects the underlying pathology.

Practical Issues for Retroperitoneal Sarcoma

Background

Retroperitoneal sarcoma is rare. Using initial specimens on biopsy, a definitive diagnosis of histological subtypes is ideal but not always achievable.

Methods

A retrospective institutional review was performed for all cases of adult retroperitoneal sarcoma from 1996 to 2015. A review of the literature was also performed related to the distribution of retroperitoneal sarcoma subtypes. A meta-analysis was performed.

Results

Liposarcoma is the most common subtype (45%), followed by leiomyosarcoma (21%), not otherwise specified (8%), and undifferentiated pleomorphic sarcoma (6%) by literature review. Data from Moffitt Cancer Center demonstrate the same general distribution for subtypes of retroperitoneal sarcoma. A pathology-based algorithm for the diagnosis of retroperitoneal sarcoma is illustrated, and common pitfalls in the pathology of retroperitoneal sarcoma are discussed.

Conclusions

An informative diagnosis of retroperitoneal sarcoma via specimens on biopsy is achievable and meaningful to guide effective therapy. A practical and multidisciplinary algorithm focused on the histopathology is helpful for the management of retroperitoneal sarcoma.

En-bloc resection of a giant retroperitoneal lipoma: a case report and review of the literature

BACKGROUND

Retroperitoneal lipomas are an extremely rare condition with only 17 cases described in the literature since 1980. They can reach enormous size and cause significant abdominal symptoms. The most important differential diagnosis is the well-differentiated liposarcoma, which preoperatively often may not definitely be ruled out.

CASE PRESENTATION

We present the case of a 73 year-old Caucasian patient with a giant retroperitoneal lipoma of 9 kg measuring 55 cm in diameter. The patient presented with abdominal pain and swelling that had been slowly progressive for the last 15 years. On computerized tomography an immense retroperitoneal tumor was revealed. Intraoperatively, the tumor did not show any signs of infiltrative growth, therefore sole tumor extirpation was performed.

CONCLUSION

Retroperitoneal lipomas are not clearly distinguishable from well-differentiated liposarcomas on imaging and even biopsies may be misleading. Moreover, abdominal symptoms, i.e. pain, obstipation and dysphagia may occur due to mechanical displacement. Therefore, surgical exploration with complete oncological resection is the therapy of choice if malignity cannot be ruled out.

A screening of a library of T7 phage-displayed peptide identifies E2F-4 as an etoposide-binding protein

Etoposide (VP-16) is an anti-tumor compound that targets topoisomerase II (top II). In this study, we have identified an alternative binding protein of etoposide by screening a library of T7 phage-displayed peptides. After four rounds of selection using a biotinylated etoposide derivative immobilized on a streptavidin-coated plate, T7 phage particles that display a 16-mer peptide NSSASSRGNSSSNSVY (ETBP16) or a 10-mer NSLRKYSKLK (ETBP10) were enriched with the ratio of 40 or 11 out of the 69 clones, respectively. Binding of etoposide to these peptides was confirmed by surface plasmon resonance (SPR) analysis, which showed ETBP16 and ETBP10 to have a kinetic constant of 4.85 × 10⁻⁵ M or 6.45 × 10⁻⁵ M, respectively. ETBP16 displays similarity with the ser-rich domain in E2F-4, a transcription factor in cell cycle-regulated genes, suggesting that etoposide might interact with E2F-4 via this domain. SPR analysis confirmed the specific binding of etoposide to recombinant E2F-4 is in the order of 10⁻⁵ M. Furthermore, etoposide was shown to inhibit luciferase reporter gene expression mediated by the heterodimeric E2F-4/DP complex. Taken together, our results suggest that etoposide directly binds to E2F-4 and inhibits subsequent gene transcription mediated by heterodimeric E2F-4/DP complexes in the nucleus.