Detection of MDM2 amplification by shallow whole genome sequencing of cell-free DNA of patients with dedifferentiated liposarcoma

High-level amplification of MDM2 and other genes in the 12q13–15 locus is a hallmark genetic feature of well-differentiated and dedifferentiated liposarcomas (WDLPS and DDLPS, respectively). Detection of this genomic aberration in plasma cell-free DNA may be a clinically useful assay for non-invasive distinction between these liposarcomas and other retroperitoneal tumors in differential diagnosis, and might be useful for the early detection of disease recurrence. In this study, we performed shallow whole genome sequencing of cell-free DNA extracted from 10 plasma samples from 3 patients with DDLPS and 1 patient with WDLPS. In addition, we studied 31 plasma samples from 11 patients with other types of soft tissue tumors. We detected MDM2 amplification in cell-free DNA of 2 of 3 patients with DDLPS. By applying a genome-wide approach to the analysis of cell-free DNA, we also detected amplification of other genes that are known to be recurrently affected in DDLPS. Based on the analysis of one patient with DDLPS with longitudinal plasma samples available, we show that tracking MDM2 amplification in cell-free DNA may be potentially useful for evaluation of response to treatment. The patient with WDLPS and patients with other soft tissue tumors in differential diagnosis were negative for the MDM2 amplification in cell-free DNA. In summary, we demonstrate the feasibility of detecting amplification of MDM2 and other DDLPS-associated genes in plasma cell-free DNA using technology that is already routinely applied for other clinical indications. Our results may have clinical implications for improved diagnosis and surveillance of patients with retroperitoneal tumors.

LAMN as a differential diagnosis for abdominal pain: a case report from Syria

Low-grade appendiceal mucinous neoplasms (LAMNs) are papillary or flat mucinous tumors with low-grade cytologic atypia found in <0.3% of appendectomy specimens among older population. They are the most frequent source of pseudomyxoma peritonei. They can be easily misdiagnosed, due to unspecific symptoms, with acute appendicitis, retroperitoneal tumors or adnexal mass. Macroscopically, the appendix may appear normal or be variably dilated. Microscopic study determines whether the studied specimen is LAMN or mucinous adenocarcinomas. We report a 77-year-old patient presented with 15-day abdominal pain accompanied with chills and hyperthermia. Decision was made for right hemicolectomy as a result of the findings on ultrasound and computed tomography scan. Diagnosis was made after the pathologic study, which revealedLAMN.

Clinical Experience and Management Strategy of Retroperitoneal Tumor With Venous Tumor Thrombus Involvement

Background: To report the surgical management, complications, and outcomes for patients with retroperitoneal tumor and venous thrombus Methods: We retrospectively analyzed 19 cases of retroperitoneal tumor with venous tumor thrombus from August 2015 to March 2021. According to the characteristics of surgical techniques, a new tumor thrombus PUTH grading system was proposed. Results: There were 2 cases of PUTH-1a, 2 cases of PUTH-1b, 6 cases of PUTH-2, 6 cases of PUTH-3,3 cases of PUTH-4. All the operations were successfully performed in 19 patients. Among them, 5 cases (26.3%) were operated by completely laparoscopic approach and 13 cases (68.4%) were operated by open approach. One case (5.3%) was converted from laparoscopic approach to open approach. 5 cases experienced postoperative complications, the incidence was 26.3%. All the cases were followed-up for a median of 14 months. Cancer associated death were occurred in 3 cases. Distant metastases were occurred in 7 cases. Conclusions: In this study, we proposed a new tumor thrombus grading system based on the anatomical characteristics of retroperitoneal tumors with venous tumor thrombus. Retroperitoneal tumor resection and removal of venous tumor thrombus are safe and effective in the treatment of such diseases.

Retroperitoneal Liposarcoma Presenting as Bilateral Inguinal Hernias

Liposarcoma is one of the most common soft tissue sarcomas and has multiple subtypes, including atypical, well-differentiated, and dedifferentiated liposarcoma1. These tumors most commonly occur in the extremities and the retroperitoneum2, and account for 20% of all retroperitoneal tumors3. Retroperitoneal liposarcoma is very rare overall, occurring in 2.5 per one million people4. Patients will present from symptoms of mass effect due to the uncontrolled growth in the large potential space of the retroperitoneum, with its median size being around 30 cm5. The mainstay of treatment for this type of tumor is resection to a negative margin6. This is a case report describing a retroperitoneal liposarcoma presenting with bilateral inguinal hernias containing intraperitoneal fat from mass effect.

Radio-pathological correlation of a retroperitoneal teratoma in a 2-year-old girl: a case report

ABSTRACTRetroperitoneal teratoma is a extragonadal germ cell tumor comprising 5% of all teratomas in children, and the third most common retroperitoneal neoplasm in children. This is a case report of a 2 years old girl who presented with abdominal distension and palpable mass. The imaging findings of the mass was characteristic of retroperitoneal teratoma which was confirmed by histopathology report following complete excision. Retroperitoneal tumor is an uncommon tumor in children with characteristic imaging findings. Computed tomography is mainly used to evaluate the extent of the disease. Most of the retroperitoneal tumors are benign and curable with complete surgical excision.